diff --git a/src/coreclr/debug/daccess/daccess.cpp b/src/coreclr/debug/daccess/daccess.cpp
index 097c4ff170a80e..297fd552419fe7 100644
--- a/src/coreclr/debug/daccess/daccess.cpp
+++ b/src/coreclr/debug/daccess/daccess.cpp
@@ -95,20 +95,19 @@ ConvertUtf8(_In_ LPCUTF8 utf8,
             ULONG32* nameLen,
             _Out_writes_to_opt_(bufLen, *nameLen) PWSTR buffer)
 {
+    size_t cchUtf8 = strlen(utf8) + 1;
+
     if (nameLen)
     {
-        *nameLen = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, NULL, 0);
-        if (!*nameLen)
-        {
-            return HRESULT_FROM_GetLastError();
-        }
+        size_t cchName = minipal_get_length_utf8_to_utf16(utf8, cchUtf8, 0);
+        *nameLen = (ULONG32)cchName;
     }
 
     if (buffer && bufLen)
     {
-        if (!MultiByteToWideChar(CP_UTF8, 0, utf8, -1, buffer, bufLen))
+        if (!minipal_convert_utf8_to_utf16(utf8, cchUtf8, (CHAR16_T*)buffer, bufLen, 0))
         {
-            return HRESULT_FROM_GetLastError();
+            return HRESULT_FROM_WIN32(errno);
         }
     }
 
@@ -120,20 +119,23 @@ AllocUtf8(_In_opt_ LPCWSTR wstr,
           ULONG32 srcChars,
           _Outptr_ LPUTF8* utf8)
 {
-    ULONG32 chars = WideCharToMultiByte(CP_UTF8, 0, wstr, srcChars,
-                                           NULL, 0, NULL, NULL);
-    if (!chars)
+    if (wstr == NULL || srcChars == 0)
     {
-        return HRESULT_FROM_GetLastError();
+        return E_INVALIDARG;
     }
 
+    size_t cchSrc = srcChars == (ULONG32)-1 ? u16_strlen(wstr) + 1 : srcChars;
+    size_t chars = minipal_get_length_utf16_to_utf8((const CHAR16_T*)wstr, cchSrc, 0);
+
     // Make sure the converted string is always terminated.
     if (srcChars != (ULONG32)-1)
     {
-        if (!ClrSafeInt<ULONG32>::addition(chars, 1, chars))
+        S_SIZE_T charsWithNull = S_SIZE_T(chars) + S_SIZE_T(1);
+        if (charsWithNull.IsOverflow())
         {
             return HRESULT_FROM_WIN32(ERROR_ARITHMETIC_OVERFLOW);
         }
+        chars = charsWithNull.Value();
     }
 
     char* mem = new (nothrow) char[chars];
@@ -142,10 +144,9 @@ AllocUtf8(_In_opt_ LPCWSTR wstr,
         return E_OUTOFMEMORY;
     }
 
-    if (!WideCharToMultiByte(CP_UTF8, 0, wstr, srcChars,
-                                mem, chars, NULL, NULL))
+    if (!minipal_convert_utf16_to_utf8((const CHAR16_T*)wstr, cchSrc, mem, chars, 0))
     {
-        HRESULT hr = HRESULT_FROM_GetLastError();
+        HRESULT hr = HRESULT_FROM_WIN32(errno);
         delete [] mem;
         return hr;
     }
diff --git a/src/coreclr/debug/di/rsmain.cpp b/src/coreclr/debug/di/rsmain.cpp
index d41431301322fb..4b0a5ce52a7b3f 100644
--- a/src/coreclr/debug/di/rsmain.cpp
+++ b/src/coreclr/debug/di/rsmain.cpp
@@ -1873,11 +1873,8 @@ HRESULT Cordb::CreateObject(CorDebugInterfaceVersion iDebuggerVersion, DWORD pid
     if (lpApplicationGroupId != NULL)
     {
         // Get length of target string
-        int cbMultiByte = WideCharToMultiByte(CP_ACP, 0, lpApplicationGroupId, -1, NULL, 0, NULL, NULL);
-        if (cbMultiByte == 0)
-        {
-            return E_FAIL;
-        }
+        size_t cchApplicationGroupId = u16_strlen(lpApplicationGroupId) + 1;
+        size_t cbMultiByte = minipal_get_length_utf16_to_utf8((const CHAR16_T*)lpApplicationGroupId, cchApplicationGroupId, 0);
 
         applicationGroupId = new (nothrow) CHAR[cbMultiByte];
         if (applicationGroupId == NULL)
@@ -1885,8 +1882,7 @@ HRESULT Cordb::CreateObject(CorDebugInterfaceVersion iDebuggerVersion, DWORD pid
             return (E_OUTOFMEMORY);
         }
 
-        /* Convert to ASCII */
-        cbMultiByte = WideCharToMultiByte(CP_ACP, 0, lpApplicationGroupId, -1, applicationGroupId, cbMultiByte, NULL, NULL);
+        cbMultiByte = minipal_convert_utf16_to_utf8((const CHAR16_T*)lpApplicationGroupId, cchApplicationGroupId, applicationGroupId, cbMultiByte, 0);
         if (cbMultiByte == 0)
         {
             delete [] applicationGroupId;
diff --git a/src/coreclr/debug/ee/debugger.cpp b/src/coreclr/debug/ee/debugger.cpp
index 449e64f7ee8b7c..549a421b0c0569 100644
--- a/src/coreclr/debug/ee/debugger.cpp
+++ b/src/coreclr/debug/ee/debugger.cpp
@@ -920,8 +920,10 @@ void Debugger::InitDebugEventCounting()
     if (wstrValue != NULL)
     {
         LPSTR   strValue;
-        int     cbReq;
-        cbReq = WideCharToMultiByte(CP_UTF8, 0, wstrValue,-1, 0,0, 0,0);
+        size_t  cbReq;
+        const CHAR16_T* wszValue = (const CHAR16_T*)(LPWSTR)wstrValue;
+        size_t  cchValue = u16_strlen(wstrValue) + 1;
+        cbReq = minipal_get_length_utf16_to_utf8(wszValue, cchValue, 0);
 
         strValue = new (nothrow) char[cbReq+1];
         // This is a debug only thingy, if it fails, not worth taking
@@ -931,7 +933,7 @@ void Debugger::InitDebugEventCounting()
 
 
         // now translate the unicode to ansi string
-        WideCharToMultiByte(CP_UTF8, 0, wstrValue, -1, strValue, cbReq+1, 0,0);
+        minipal_convert_utf16_to_utf8(wszValue, cchValue, strValue, cbReq+1, 0);
         char *szEnd = (char *)strchr(strValue, ';');
         char *szStart = strValue;
         while (szEnd != NULL)
diff --git a/src/coreclr/dlls/mscordac/mscordac_unixexports.src b/src/coreclr/dlls/mscordac/mscordac_unixexports.src
index b1edc440164e6f..b21c32431ad380 100644
--- a/src/coreclr/dlls/mscordac/mscordac_unixexports.src
+++ b/src/coreclr/dlls/mscordac/mscordac_unixexports.src
@@ -76,7 +76,6 @@ nativeStringResourceTable_mscorrc
 #GetSystemInfo
 #LoadLibraryExA
 #LoadLibraryExW
-#MultiByteToWideChar
 #OutputDebugStringW
 #OutputDebugStringA
 #RaiseException
@@ -86,6 +85,5 @@ nativeStringResourceTable_mscorrc
 #SetThreadDescription
 #SwitchToThread
 #TerminateProcess
-#WideCharToMultiByte
 
 #GUID_NULL
diff --git a/src/coreclr/dlls/mscoree/exports.cpp b/src/coreclr/dlls/mscoree/exports.cpp
index ebe873e80bf59e..24ccdf5d250727 100644
--- a/src/coreclr/dlls/mscoree/exports.cpp
+++ b/src/coreclr/dlls/mscoree/exports.cpp
@@ -133,13 +133,14 @@ struct HostPropertyArraysTraits final
 // Convert 8 bit string to unicode
 static LPCWSTR StringToUnicode(LPCSTR str)
 {
-    int length = MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);
+    size_t cch = strlen(str) + 1;
+    size_t length = minipal_get_length_utf8_to_utf16(str, cch, 0);
     ASSERTE_ALL_BUILDS(length != 0);
 
     LPWSTR result = new (nothrow) WCHAR[length];
     ASSERTE_ALL_BUILDS(result != NULL);
 
-    length = MultiByteToWideChar(CP_UTF8, 0, str, -1, result, length);
+    length = minipal_convert_utf8_to_utf16(str, cch, (CHAR16_T*)result, length, 0);
     ASSERTE_ALL_BUILDS(length != 0);
 
     return result;
diff --git a/src/coreclr/gc/gccommon.cpp b/src/coreclr/gc/gccommon.cpp
index e1827fb37b5e48..9825efb7d780b3 100644
--- a/src/coreclr/gc/gccommon.cpp
+++ b/src/coreclr/gc/gccommon.cpp
@@ -12,6 +12,7 @@
 
 #include "gcenv.h"
 #include "gc.h"
+#include <minipal/utf8.h>
 
 IGCHeapInternal* g_theGCHeap;
 IGCHandleManager* g_theGCHandleManager;
@@ -131,7 +132,16 @@ FILE* CreateLogFile(const GCConfigStringHolder& temp_logfile_name, bool is_confi
     const char* suffix = is_config ? ".config.log" : ".log";
     //_snprintf_s(logfile_name, MAX_LONGPATH+1, _TRUNCATE, "%s.%d%s", temp_logfile_name.Get(), pid, suffix);
     _snprintf_s(logfile_name, MAX_LONGPATH+1, _TRUNCATE, "%s%s", temp_logfile_name.Get(), suffix);
+#ifdef TARGET_WINDOWS
+    // Config strings are UTF-8; fopen would interpret them as the ANSI code page.
+    size_t nameLen = strlen(logfile_name) + 1;
+    size_t wlen = minipal_get_length_utf8_to_utf16(logfile_name, nameLen, 0);
+    WCHAR* wpath = (WCHAR*)_alloca(wlen * sizeof(WCHAR));
+    minipal_convert_utf8_to_utf16(logfile_name, nameLen, (CHAR16_T*)wpath, wlen, 0);
+    logFile = _wfopen(wpath, L"wb");
+#else
     logFile = fopen(logfile_name, "wb");
+#endif
 
     if (logFile == NULL)
     {
diff --git a/src/coreclr/hosts/corerun/corerun.hpp b/src/coreclr/hosts/corerun/corerun.hpp
index 0cfdd44be9620f..ea0fff64883d1a 100644
--- a/src/coreclr/hosts/corerun/corerun.hpp
+++ b/src/coreclr/hosts/corerun/corerun.hpp
@@ -16,6 +16,7 @@
 #include <functional>
 #include <memory>
 #include <minipal/utils.h>
+#include <minipal/utf8.h>
 
 // Class used to perform specific actions.
 class platform_specific_actions;
@@ -211,12 +212,13 @@ namespace pal
 
     inline string_utf8_t convert_to_utf8(const char_t* str)
     {
-        int bytes_req = ::WideCharToMultiByte(CP_UTF8, 0, str, -1, nullptr, 0, nullptr, nullptr);
+        size_t length = ::wcslen(str) + 1;
+        size_t bytes_req = minipal_get_length_utf16_to_utf8((const CHAR16_T*)str, length, 0);
 
         malloc_ptr<char> buffer{ (char*)::malloc(bytes_req) };
         assert(buffer != nullptr);
 
-        int written = ::WideCharToMultiByte(CP_UTF8, 0, str, -1, buffer.get(), bytes_req, nullptr, nullptr);
+        size_t written = minipal_convert_utf16_to_utf8((const CHAR16_T*)str, length, buffer.get(), bytes_req, 0);
         assert(bytes_req == written);
 
         return { buffer.get() };
@@ -224,12 +226,13 @@ namespace pal
 
     inline string_t convert_from_utf8(const char* str)
     {
-        int wchar_req = ::MultiByteToWideChar(CP_UTF8, 0, str, -1, nullptr, 0);
+        size_t length = ::strlen(str) + 1;
+        size_t wchar_req = minipal_get_length_utf8_to_utf16(str, length, 0);
 
         malloc_ptr<wchar_t> buffer{ (wchar_t*)::malloc(wchar_req * sizeof(wchar_t)) };
         assert(buffer != nullptr);
 
-        int written = ::MultiByteToWideChar(CP_UTF8, 0, str, -1, buffer.get(), wchar_req);
+        size_t written = minipal_convert_utf8_to_utf16(str, length, (CHAR16_T*)buffer.get(), wchar_req, 0);
         assert(wchar_req == written);
 
         return { buffer.get() };
diff --git a/src/coreclr/ilasm/asmman.cpp b/src/coreclr/ilasm/asmman.cpp
index fcd3a71c9b4542..d8d5264e365d31 100644
--- a/src/coreclr/ilasm/asmman.cpp
+++ b/src/coreclr/ilasm/asmman.cpp
@@ -28,7 +28,7 @@ BinStr* BinStrToUnicode(BinStr* pSource, bool Swap)
             if(wz)
             {
                 memset(wz,0,L);
-                MultiByteToWideChar(g_uCodePage,0,pb,-1,wz,l);
+                minipal_convert_utf8_to_utf16(pb,strlen(pb)+1,(CHAR16_T*)wz,l,0);
                 tmp->remove(L-(DWORD)u16_strlen(wz)*sizeof(WCHAR));
 #if BIGENDIAN
                 if (Swap)
@@ -205,7 +205,7 @@ void    AsmMan::EmitFiles()
         if(!tmp->m_fNew) continue;
         tmp->m_fNew = FALSE;
 
-        MultiByteToWideChar(g_uCodePage,0,tmp->szName,-1,wzUniBuf,dwUniBuf);
+        minipal_convert_utf8_to_utf16(tmp->szName,strlen(tmp->szName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
         if(tmp->pHash==NULL) // if hash not explicitly specified
         {
             if(m_pAssembly      // and assembly is defined
@@ -553,7 +553,7 @@ void    AsmMan::EmitAssemblyRefs()
             dwFlags |= afPublicKey;
         }
         // Convert name to Unicode
-        MultiByteToWideChar(g_uCodePage,0,m_pCurAsmRef->szName,-1,wzUniBuf,dwUniBuf);
+        minipal_convert_utf8_to_utf16(m_pCurAsmRef->szName,strlen(m_pCurAsmRef->szName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
         hr = m_pAsmEmitter->DefineAssemblyRef(       // S_OK or error.
                     pbPublicKeyOrToken,              // [IN] Public key or token of the assembly.
                     cbPublicKeyOrToken,              // [IN] Count of bytes in the key or token.
@@ -588,7 +588,7 @@ void    AsmMan::EmitAssembly()
     FillAssemblyMetadata(m_pAssembly, &md);
 
     // Convert name to Unicode
-    MultiByteToWideChar(g_uCodePage,0,m_pAssembly->szName,-1,wzUniBuf,dwUniBuf);
+    minipal_convert_utf8_to_utf16(m_pAssembly->szName,strlen(m_pAssembly->szName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
 
     hr = m_pAsmEmitter->DefineAssembly(              // S_OK or error.
         (const void*)(m_sStrongName.m_pbPublicKey), // [IN] Public key of the assembly.
@@ -857,7 +857,7 @@ HRESULT AsmMan::EmitManifest()
             if(!pComType->m_fNew) continue;
             pComType->m_fNew = FALSE;
 
-            MultiByteToWideChar(g_uCodePage,0,pComType->szName,-1,wzUniBuf,dwUniBuf);
+            minipal_convert_utf8_to_utf16(pComType->szName,strlen(pComType->szName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
             mdToken     tkImplementation = mdTokenNil;
             if(pComType->tkImpl) tkImplementation = pComType->tkImpl;
             else if(pComType->szFileName)
@@ -930,7 +930,7 @@ HRESULT AsmMan::EmitManifest()
             if(!pManRes->m_fNew) continue;
             pManRes->m_fNew = FALSE;
 
-            MultiByteToWideChar(g_uCodePage,0,pManRes->szAlias,-1,wzUniBuf,dwUniBuf);
+            minipal_convert_utf8_to_utf16(pManRes->szAlias,strlen(pManRes->szAlias)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
             if(pManRes->szAsmRefName)
             {
                 tkImplementation = GetAsmRefTokByName(pManRes->szAsmRefName);
@@ -1007,7 +1007,7 @@ HRESULT AsmMan::EmitManifest()
             }
             if(fOK || ((Assembler*)m_pAssembler)->OnErrGo)
             {
-                MultiByteToWideChar(g_uCodePage,0,pManRes->szName,-1,wzUniBuf,dwUniBuf);
+                minipal_convert_utf8_to_utf16(pManRes->szName,strlen(pManRes->szName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
                 hr = m_pAsmEmitter->DefineManifestResource(         // S_OK or error.
                         (LPCWSTR)wzUniBuf,                          // [IN] Name of the resource.
                         tkImplementation,                           // [IN] mdFile or mdAssemblyRef that provides the resource.
diff --git a/src/coreclr/ilasm/asmparse.h b/src/coreclr/ilasm/asmparse.h
index aa576898fd8c14..9ff8598799af43 100644
--- a/src/coreclr/ilasm/asmparse.h
+++ b/src/coreclr/ilasm/asmparse.h
@@ -106,9 +106,10 @@ class MappedFileStream : public ReadStream {
 
         if (IsValid())
         {
-            int len = WideCharToMultiByte(CP_UTF8,0,wFileName,-1,NULL,0,NULL,NULL);
+            size_t cch = u16_strlen(wFileName)+1;
+            size_t len = minipal_get_length_utf16_to_utf8((const CHAR16_T*)wFileName,cch,0);
             m_fileNameUtf8 = new char[len+1];
-            WideCharToMultiByte(CP_UTF8,0,wFileName,-1,m_fileNameUtf8,len+1,NULL,NULL);
+            minipal_convert_utf16_to_utf8((const CHAR16_T*)wFileName,cch,m_fileNameUtf8,len+1,0);
         }
     }
     ~MappedFileStream()
diff --git a/src/coreclr/ilasm/assem.cpp b/src/coreclr/ilasm/assem.cpp
index 912ab2f3c9b2b3..b178543e48e370 100644
--- a/src/coreclr/ilasm/assem.cpp
+++ b/src/coreclr/ilasm/assem.cpp
@@ -22,7 +22,6 @@
 void indexKeywords(Indx* indx); // defined in asmparse.y
 
 unsigned int g_uCodePage = CP_ACP;
-unsigned int g_uConsoleCP = CP_ACP;
 
 char g_szSourceFileName[MAX_FILENAME_LENGTH*3];
 
@@ -605,7 +604,7 @@ void Assembler::EmitImports()
     mdToken tk;
     for(i=0; (pID = m_ImportList.PEEK(i)); i++)
     {
-        MultiByteToWideChar(g_uCodePage,0,pID->szDllName,-1,wzDllName,dwUniBuf-1);
+        minipal_convert_utf8_to_utf16(pID->szDllName,strlen(pID->szDllName)+1,(CHAR16_T*)wzDllName,dwUniBuf-1,0);
         if(FAILED(m_pEmitter->DefineModuleRef(             // S_OK or error.
                             wzDllName,            // [IN] DLL name
                             &tk)))      // [OUT] returned
@@ -619,7 +618,7 @@ HRESULT Assembler::EmitPinvokeMap(mdToken tk, PInvokeDescriptor* pDescr)
 {
     WCHAR*               wzAlias=&wzUniBuf[0];
 
-    if(pDescr->szAlias) MultiByteToWideChar(g_uCodePage,0,pDescr->szAlias,-1,wzAlias,dwUniBuf-1);
+    if(pDescr->szAlias) minipal_convert_utf8_to_utf16(pDescr->szAlias,strlen(pDescr->szAlias)+1,(CHAR16_T*)wzAlias,dwUniBuf-1,0);
 
     return m_pEmitter->DefinePinvokeMap(        // Return code.
                         tk,                     // [IN] FieldDef, MethodDef or MethodImpl.
@@ -657,7 +656,7 @@ BOOL Assembler::EmitMethod(Method *pMethod)
     ClassToken = (pMethod->IsGlobalMethod())? mdTokenNil
                                     : pMethod->m_pClass->m_cl;
     // Convert name to UNICODE
-    MultiByteToWideChar(g_uCodePage,0,pszMethodName,-1,wzMemberName,dwUniBuf-1);
+    minipal_convert_utf8_to_utf16(pszMethodName,strlen(pszMethodName)+1,(CHAR16_T*)wzMemberName,dwUniBuf-1,0);
 
     if(IsMdPrivateScope(pMethod->m_Attr))
     {
@@ -801,7 +800,7 @@ BOOL Assembler::EmitMethod(Method *pMethod)
             if(pAN->dwName) strcpy_s(szPhonyName,dwUniBuf >> 1,pAN->szName);
             else sprintf_s(szPhonyName,(dwUniBuf >> 1),"A_%d",pAN->nNum);
 
-            MultiByteToWideChar(g_uCodePage,0,szPhonyName,-1,wzParName,dwUniBuf >> 1);
+            minipal_convert_utf8_to_utf16(szPhonyName,strlen(szPhonyName)+1,(CHAR16_T*)wzParName,dwUniBuf >> 1,0);
 
             if(pAN->pValue)
             {
@@ -904,7 +903,7 @@ BOOL Assembler::EmitEvent(EventDescriptor* pED)
 
     if(!pED) return FALSE;
 
-    MultiByteToWideChar(g_uCodePage,0,pED->m_szName,-1,wzMemberName,dwUniBuf-1);
+    minipal_convert_utf8_to_utf16(pED->m_szName,strlen(pED->m_szName)+1,(CHAR16_T*)wzMemberName,dwUniBuf-1,0);
 
     mdAddOn = ResolveLocalMemberRef(pED->m_tkAddOn);
     if(TypeFromToken(mdAddOn) != mdtMethodDef)
@@ -964,7 +963,7 @@ BOOL Assembler::EmitProp(PropDescriptor* pPD)
 
     if(!pPD) return FALSE;
 
-    MultiByteToWideChar(g_uCodePage,0,pPD->m_szName,-1,wzMemberName,dwUniBuf-1);
+    minipal_convert_utf8_to_utf16(pPD->m_szName,strlen(pPD->m_szName)+1,(CHAR16_T*)wzMemberName,dwUniBuf-1,0);
 
     mdSet = ResolveLocalMemberRef(pPD->m_tkSet);
     if((RidFromToken(mdSet)!=0)&&(TypeFromToken(mdSet) != mdtMethodDef))
@@ -1091,7 +1090,7 @@ BOOL Assembler::EmitClass(Class *pClass)
     else
         szFullName = pClass->m_szFQN;
 
-    MultiByteToWideChar(g_uCodePage,0,szFullName,-1,wzFullName,dwUniBuf);
+    minipal_convert_utf8_to_utf16(szFullName,strlen(szFullName)+1,(CHAR16_T*)wzFullName,dwUniBuf,0);
 
     L = u16_strlen(wzFullName);
     if((L==0)||(wzFullName[L-1]==L'.')) // Missing class name!
@@ -1364,7 +1363,7 @@ char* Assembler::ReflectionNotation(mdToken tk)
                 mdToken tkResScope;
                 if(SUCCEEDED(m_pImporter->GetTypeRefProps(tk,&tkResScope,wzUniBuf,cchUniBuf,&N)))
                 {
-                    int ret = WideCharToMultiByte(CP_UTF8,0,wzUniBuf,-1,sz,szSizeBytes,NULL,NULL);
+                    size_t ret = minipal_convert_utf16_to_utf8((const CHAR16_T*)wzUniBuf,u16_strlen(wzUniBuf)+1,sz,szSizeBytes,0);
                     if(TypeFromToken(tkResScope)==mdtAssemblyRef)
                     {
                         AsmManAssembly *pAsmRef = m_pManifest->m_AsmRefLst.PEEK(RidFromToken(tkResScope)-1);
@@ -1403,8 +1402,8 @@ char* Assembler::ReflectionNotation(mdToken tk)
                                 {
                                     memcpy(wzUniBuf,pAsmRef->pLocale->ptr(),L);
                                     wzUniBuf[L>>1] = 0;
-                                    ret = WideCharToMultiByte(CP_UTF8,0,wzUniBuf,-1,pc,(int)szRemainingSizeBytes,NULL,NULL);
-                                    if (ret <= 0)
+                                    ret = minipal_convert_utf16_to_utf8((const CHAR16_T*)wzUniBuf,u16_strlen(wzUniBuf)+1,pc,szRemainingSizeBytes,0);
+                                    if (ret == 0)
                                     {
                                         report->error("Locale too long.\n");
                                         *sz=0;
@@ -1413,7 +1412,7 @@ char* Assembler::ReflectionNotation(mdToken tk)
                                     else
                                     {
                                         pc += ret;
-                                        szRemainingSizeBytes -= (size_t)ret;
+                                        szRemainingSizeBytes -= ret;
                                     }
                                 }
                             }
diff --git a/src/coreclr/ilasm/assembler.cpp b/src/coreclr/ilasm/assembler.cpp
index 5096bbdda453fa..3c45d0fc655ff8 100644
--- a/src/coreclr/ilasm/assembler.cpp
+++ b/src/coreclr/ilasm/assembler.cpp
@@ -373,7 +373,7 @@ mdToken Assembler::MakeTypeRef(mdToken tkResScope, LPCUTF8 pszFullClassName)
         if(*pc)
         {
             // convert name to widechar
-            MultiByteToWideChar(g_uCodePage,0,pc,-1,wzUniBuf,dwUniBuf);
+            minipal_convert_utf8_to_utf16(pc,strlen(pc)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
             if(FAILED(m_pEmitter->DefineTypeRefByName(tkResScope, wzUniBuf, &tkRet))) tkRet = mdTokenNil;
         }
     }
@@ -910,7 +910,7 @@ BOOL Assembler::EmitField(FieldDescriptor* pFD)
     cSig = pFD->m_pbsSig->length();
     mySig = (COR_SIGNATURE*)(pFD->m_pbsSig->ptr());
 
-    MultiByteToWideChar(g_uCodePage,0,pFD->m_szName,-1,wzFieldName,dwUniBuf); //int)cFieldNameLength);
+    minipal_convert_utf8_to_utf16(pFD->m_szName,strlen(pFD->m_szName)+1,(CHAR16_T*)wzFieldName,dwUniBuf,0); //int)cFieldNameLength);
     if(IsFdPrivateScope(pFD->m_dwAttr))
     {
         WCHAR* p = (WCHAR*)u16_strstr(wzFieldName,W("$PST04"));
@@ -1368,7 +1368,7 @@ void Assembler::EmitDataString(BinStr* str)
 
         if(UnicodeString)
         {
-            MultiByteToWideChar(g_uCodePage,0,pb,-1,UnicodeString,DataLen);
+            minipal_convert_utf8_to_utf16(pb,strlen(pb)+1,(CHAR16_T*)UnicodeString,DataLen,0);
             EmitData(UnicodeString,DataLen*sizeof(WCHAR));
             if(DataLen >= dwUniBuf) delete [] UnicodeString;
         }
@@ -1777,7 +1777,7 @@ mdToken Assembler::MakeMemberRef(mdToken cr, _In_ __nullterminated char* pszMemb
     }
     else
     {
-        MultiByteToWideChar(g_uCodePage,0,pszMemberName,-1,wzUniBuf,dwUniBuf);
+        minipal_convert_utf8_to_utf16(pszMemberName,strlen(pszMemberName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
 
         if(cr == mdTokenNil) cr = mdTypeRefNil;
         if(TypeFromToken(cr) == mdtAssemblyRef)
@@ -1998,7 +1998,8 @@ void Assembler::SetPropMethod(int MethodCode, mdToken tk)
 /**************************************************************************/
 void Assembler::EmitInstrStringLiteral(Instr* instr, BinStr* literal, BOOL ConvertToUnicode, BOOL Swap /*=FALSE*/)
 {
-    DWORD   DataLen = literal->length(),L;
+    DWORD   DataLen = literal->length();
+    size_t  L;
     uint8_t *pb = literal->ptr();
     HRESULT hr = S_OK;
     mdToken tk;
@@ -2014,7 +2015,7 @@ void Assembler::EmitInstrStringLiteral(Instr* instr, BinStr* literal, BOOL Conve
         literal->appendInt8(0);
         pb = literal->ptr();
         // convert string to Unicode
-        L = UnicodeString ? MultiByteToWideChar(g_uCodePage,0,(char*)pb,-1,UnicodeString,DataLen+1) : 0;
+        L = UnicodeString ? minipal_convert_utf8_to_utf16((char*)pb,strlen((char*)pb)+1,(CHAR16_T*)UnicodeString,DataLen+1,0) : 0;
         if(L == 0)
         {
             const char* sz=NULL;
@@ -2051,7 +2052,7 @@ void Assembler::EmitInstrStringLiteral(Instr* instr, BinStr* literal, BOOL Conve
     // Add the string data to the metadata, which will fold dupes.
     hr = m_pEmitter->DefineUserString(
         UnicodeString,
-        L,
+        (ULONG)L,
         &tk
     );
     if (FAILED(hr))
@@ -2412,7 +2413,7 @@ void Assembler::SetPdbFileName(_In_ __nullterminated char* szName)
         if (*szName)
         {
             strcpy_s(m_szPdbFileName, MAX_FILENAME_LENGTH * 3 + 1, szName);
-            MultiByteToWideChar(g_uCodePage, 0, szName, -1, m_wzPdbFileName, MAX_FILENAME_LENGTH);
+            minipal_convert_utf8_to_utf16(szName, strlen(szName) + 1, (CHAR16_T*)m_wzPdbFileName, MAX_FILENAME_LENGTH, 0);
         }
     }
 }
diff --git a/src/coreclr/ilasm/class.hpp b/src/coreclr/ilasm/class.hpp
index cb2c357ad56a6f..10549171e70c1b 100644
--- a/src/coreclr/ilasm/class.hpp
+++ b/src/coreclr/ilasm/class.hpp
@@ -96,7 +96,7 @@ class Class
         if(sz)
         {
             wzUniBuf[0] = 0;
-            MultiByteToWideChar(g_uCodePage,0,sz,-1,wzUniBuf,dwUniBuf);
+            minipal_convert_utf8_to_utf16(sz,strlen(sz)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
             return FindTyPar(wzUniBuf);
         }
         else return -1;
diff --git a/src/coreclr/ilasm/grammar_after.cpp b/src/coreclr/ilasm/grammar_after.cpp
index a66f8543d0b176..419dda757690d1 100644
--- a/src/coreclr/ilasm/grammar_after.cpp
+++ b/src/coreclr/ilasm/grammar_after.cpp
@@ -120,7 +120,7 @@ char* NewStrFromTokenW(_In_reads_(tokLen) void* curTok, size_t tokLen)
     char *nb = new char[(tokLen<<1) + 2];
     if(nb != NULL)
     {
-        tokLen = WideCharToMultiByte(CP_UTF8,0,(LPCWSTR)wcurTok,(int)(tokLen >> 1),nb,(int)(tokLen<<1) + 2,NULL,NULL);
+        tokLen = minipal_convert_utf16_to_utf8((const CHAR16_T*)wcurTok,tokLen >> 1,nb,(tokLen<<1) + 2,0);
         nb[tokLen] = 0;
     }
     return nb;
@@ -143,7 +143,7 @@ char* NewStaticStrFromTokenW(_In_reads_(tokLen) char* curTok, size_t tokLen, _Ou
     // CodeQL [SM02986] Cast to WCHAR is safe because we bail if curTok is not properly aligned
     WCHAR* wcurTok = (WCHAR*)curTok;
     if(tokLen >= bufSize/2) return NULL;
-    tokLen = WideCharToMultiByte(CP_UTF8,0,(LPCWSTR)wcurTok,(int)(tokLen >> 1),staticBuf,(int)bufSize,NULL,NULL);
+    tokLen = minipal_convert_utf16_to_utf8((const CHAR16_T*)wcurTok,tokLen >> 1,staticBuf,bufSize,0);
     staticBuf[tokLen] = 0;
     return staticBuf;
 }
@@ -990,7 +990,7 @@ int yylex()
                             {
                                 if((wzFile = new WCHAR[tokLen+1]) != NULL)
                                 {
-                                    tokLen = MultiByteToWideChar(g_uCodePage,0,curTok,(int)tokLen,wzFile,(int)tokLen+1);
+                                    tokLen = minipal_convert_utf8_to_utf16(curTok,tokLen,(CHAR16_T*)wzFile,tokLen+1,0);
                                     wzFile[tokLen] = 0;
                                 }
                             }
@@ -1814,15 +1814,6 @@ BinStr* AsmParse::MakeTypeClass(CorElementType kind, mdToken tk)
 /**************************************************************************/
 void PrintANSILine(FILE* pF, _In_ __nullterminated char* sz)
 {
-        WCHAR *wz = &wzUniBuf[0];
-        if(g_uCodePage != CP_ACP)
-        {
-                memset(wz,0,dwUniBuf); // dwUniBuf/2 WCHARs = dwUniBuf bytes
-                MultiByteToWideChar(g_uCodePage,0,sz,-1,wz,(dwUniBuf >> 1)-1);
-
-                memset(sz,0,dwUniBuf);
-                WideCharToMultiByte(g_uConsoleCP,0,wz,-1,sz,dwUniBuf-1,NULL,NULL);
-        }
         fprintf(pF,"%s",sz);
 }
 /**************************************************************************/
diff --git a/src/coreclr/ilasm/grammar_before.cpp b/src/coreclr/ilasm/grammar_before.cpp
index 04286fa137fb5a..523377e88fba9a 100644
--- a/src/coreclr/ilasm/grammar_before.cpp
+++ b/src/coreclr/ilasm/grammar_before.cpp
@@ -67,8 +67,6 @@ BOOL SkipToken = FALSE;
 BOOL neg = FALSE;
 BOOL newclass = FALSE;
 
-extern unsigned int g_uConsoleCP;
-
 struct VarName
 {
     char* name;
diff --git a/src/coreclr/ilasm/main.cpp b/src/coreclr/ilasm/main.cpp
index b6df0cfdd0c19a..ae417d4363850d 100644
--- a/src/coreclr/ilasm/main.cpp
+++ b/src/coreclr/ilasm/main.cpp
@@ -56,7 +56,6 @@ class NarrowForNumberParsing final
 static DWORD    g_dwSubsystem=(DWORD)-1,g_dwComImageFlags=(DWORD)-1,g_dwFileAlignment=0,g_dwTestRepeat=0;
 static ULONGLONG   g_stBaseAddress=0;
 static size_t   g_stSizeOfStackReserve=0;
-extern unsigned int g_uConsoleCP;
 
 void MakeTestFile(_In_ __nullterminated char* szFileName)
 {
@@ -98,14 +97,14 @@ void MakeProperSourceFileName(_In_ __nullterminated WCHAR* wzOrigName,
         }
     }
     while(j);
-    WideCharToMultiByte(uCodePage,0,wzProperName,-1,szProperName,MAX_FILENAME_LENGTH*3-1,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)wzProperName,u16_strlen(wzProperName)+1,szProperName,MAX_FILENAME_LENGTH*3-1,0);
 }
 
 char* FullFileName(_In_ __nullterminated WCHAR* wzFileName, unsigned uCodePage)
 {
 #ifdef TARGET_UNIX
     char szFileName[MAX_FILENAME_LENGTH*3];
-    WideCharToMultiByte(uCodePage,0,wzFileName,-1,szFileName,MAX_FILENAME_LENGTH*3-1,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)wzFileName,u16_strlen(wzFileName)+1,szFileName,MAX_FILENAME_LENGTH*3-1,0);
     char szCwd[PATH_MAX];
     char szFullPath[PATH_MAX + MAX_FILENAME_LENGTH*3];
     if((szFileName[0] != '/') && (getcwd(szCwd, sizeof(szCwd)) != NULL))
@@ -117,7 +116,7 @@ char* FullFileName(_In_ __nullterminated WCHAR* wzFileName, unsigned uCodePage)
     WCHAR* pwz;
     GetFullPathName(wzFileName,MAX_FILENAME_LENGTH,wzFullPath,&pwz);
     char szFullPath[MAX_FILENAME_LENGTH*3];
-    WideCharToMultiByte(uCodePage,0,wzFullPath,-1,szFullPath,MAX_FILENAME_LENGTH*3-1,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)wzFullPath,u16_strlen(wzFullPath)+1,szFullPath,MAX_FILENAME_LENGTH*3-1,0);
 #endif
     char* sz = new char[strlen(szFullPath)+1];
     if(sz) strcpy_s(sz,strlen(szFullPath)+1,szFullPath);
@@ -155,7 +154,6 @@ extern "C" int _cdecl wmain(int argc, _In_ WCHAR **argv)
     memset(&cw,0,sizeof(Clockwork));
     cw.cBegin = minipal_lowres_ticks();
 
-    g_uConsoleCP = GetConsoleOutputCP();
     memset(wzOutputFilename,0,sizeof(wzOutputFilename));
     memset(wzPdbFilename, 0, sizeof(wzPdbFilename));
 
@@ -238,7 +236,8 @@ extern "C" int _cdecl wmain(int argc, _In_ WCHAR **argv)
 #endif
                 {
                     char szOpt[3 + 1] = { 0 };
-                    WideCharToMultiByte(uCodePage, 0, &argv[i][1], 3, szOpt, sizeof(szOpt), NULL, NULL);
+                    size_t cchOpt = u16_strlen(&argv[i][1]);
+                    minipal_convert_utf16_to_utf8((const CHAR16_T*)&argv[i][1], cchOpt < 3 ? cchOpt : 3, szOpt, sizeof(szOpt), 0);
                     if (!_stricmp(szOpt, "NOA"))
                     {
                         pAsm->m_fAutoInheritFromObject = FALSE;
@@ -334,7 +333,7 @@ extern "C" int _cdecl wmain(int argc, _In_ WCHAR **argv)
                         // We could change it to be longer, but that would affect the existing usability (ARM64 was
                         // added much later). Thus, just distinguish the two here.
                         char szOpt2[5 + 1] = { 0 };
-                        WideCharToMultiByte(uCodePage, 0, &argv[i][1], 5, szOpt2, sizeof(szOpt2), NULL, NULL);
+                        minipal_convert_utf16_to_utf8((const CHAR16_T*)&argv[i][1], cchOpt < 5 ? cchOpt : 5, szOpt2, sizeof(szOpt2), 0);
                         if (!_stricmp(szOpt2, "ARM"))
                         {
                             pAsm->m_dwCeeFileFlags &= ~ICEE_CREATE_MACHINE_MASK;
@@ -702,7 +701,7 @@ extern "C" int _cdecl wmain(int argc, _In_ WCHAR **argv)
                             {
                                 char szOutputFilename[MAX_FILENAME_LENGTH*3];
                                 memset(szOutputFilename,0,sizeof(szOutputFilename));
-                                WideCharToMultiByte(uCodePage,0,wzOutputFilename,-1,szOutputFilename,MAX_FILENAME_LENGTH*3-1,NULL,NULL);
+                                minipal_convert_utf16_to_utf8((const CHAR16_T*)wzOutputFilename,u16_strlen(wzOutputFilename)+1,szOutputFilename,MAX_FILENAME_LENGTH*3-1,0);
                                 pParser->msg(" --> '%s'\n", szOutputFilename);
                             }
                         }
@@ -904,13 +903,14 @@ int main(int argc, char* str[])
 
     WCHAR **argv = new WCHAR*[argc];
     for (int i = 0; i < argc; i++) {
-        int length = MultiByteToWideChar(CP_ACP, 0, str[i], -1, NULL, 0);
+        size_t cch = strlen(str[i]) + 1;
+        size_t length = minipal_get_length_utf8_to_utf16(str[i], cch, 0);
         ASSERTE_ALL_BUILDS(length != 0);
 
         LPWSTR result = new (nothrow) WCHAR[length];
         ASSERTE_ALL_BUILDS(result != NULL);
 
-        length = MultiByteToWideChar(CP_ACP, 0, str[i], -1, result, length);
+        length = minipal_convert_utf8_to_utf16(str[i], cch, (CHAR16_T*)result, length, 0);
         ASSERTE_ALL_BUILDS (length != 0);
 
         argv[i] = result;
diff --git a/src/coreclr/ilasm/method.hpp b/src/coreclr/ilasm/method.hpp
index dfd22c1f79691f..e82b3d6ea6f139 100644
--- a/src/coreclr/ilasm/method.hpp
+++ b/src/coreclr/ilasm/method.hpp
@@ -373,7 +373,7 @@ class Method
         if(sz)
         {
             wzUniBuf[0] = 0;
-            MultiByteToWideChar(g_uCodePage,0,sz,-1,wzUniBuf,dwUniBuf);
+            minipal_convert_utf8_to_utf16(sz,strlen(sz)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
             return FindTyPar(wzUniBuf);
         }
         else return -1;
diff --git a/src/coreclr/ilasm/typar.hpp b/src/coreclr/ilasm/typar.hpp
index 5b6f94cc3adab0..de94e9f641783b 100644
--- a/src/coreclr/ilasm/typar.hpp
+++ b/src/coreclr/ilasm/typar.hpp
@@ -33,7 +33,7 @@ class TyParDescr
         if(pwzName)
         {
             memset(pwzName,0,sizeof(WCHAR)*cTemp);
-            MultiByteToWideChar(g_uCodePage,0,name,-1,pwzName,cTemp);
+            minipal_convert_utf8_to_utf16(name,strlen(name)+1,(CHAR16_T*)pwzName,cTemp,0);
         }
         m_dwAttrs = attrs;
     };
@@ -119,7 +119,7 @@ class TyParList {
             WCHAR*              wzDllName = new WCHAR [cTemp];
             // Convert name to UNICODE
             memset(wzDllName,0,sizeof(WCHAR)*cTemp);
-            MultiByteToWideChar(g_uCodePage,0,tp->name,-1,wzDllName,cTemp);
+            minipal_convert_utf8_to_utf16(tp->name,strlen(tp->name)+1,(CHAR16_T*)wzDllName,cTemp,0);
             nam[i] = (LPCWSTR)wzDllName;
             b[i] = tp->bound;
             if (attr)
diff --git a/src/coreclr/ilasm/writer.cpp b/src/coreclr/ilasm/writer.cpp
index da3e32142410c2..cd9d7e4d7f2a23 100644
--- a/src/coreclr/ilasm/writer.cpp
+++ b/src/coreclr/ilasm/writer.cpp
@@ -7,6 +7,7 @@
 
 #include "ceefilegenwriter.h"
 #include "sha256.h"
+#include <dn-stdio.h>
 
 #ifndef _MSC_VER
 //cloned definition from ntimage.h that is removed for non MSVC builds
@@ -498,7 +499,7 @@ HRESULT Assembler::CreateExportDirectory()
     Ldllname = (unsigned)u16_strlen(m_wzOutputFileName)*3+3;
     AStringHolder    szOutputFileName(new char[Ldllname]);
     memset(szOutputFileName,0,u16_strlen(m_wzOutputFileName)*3+3);
-    WideCharToMultiByte(CP_ACP,0,m_wzOutputFileName,-1,szOutputFileName,Ldllname,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)m_wzOutputFileName,u16_strlen(m_wzOutputFileName)+1,szOutputFileName,Ldllname,0);
     pszDllName = strrchr(szOutputFileName,DIRECTORY_SEPARATOR_CHAR_A);
 #ifdef TARGET_WINDOWS
     if(pszDllName == NULL) pszDllName = strrchr(szOutputFileName,':');
@@ -874,7 +875,7 @@ HRESULT Assembler::ResolveLocalMemberRefs()
                         }
                         if(tkMemberDef && ((*pMRD_pSig & IMAGE_CEE_CS_CALLCONV_MASK)==IMAGE_CEE_CS_CALLCONV_VARARG))
                         {
-                            MultiByteToWideChar(g_uCodePage,0,pMRD_szName,-1,wzUniBuf,dwUniBuf);
+                            minipal_convert_utf8_to_utf16(pMRD_szName,strlen(pMRD_szName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
 
                             if(IsMdPrivateScope(pListMD->m_Attr))
                             {
@@ -917,7 +918,7 @@ HRESULT Assembler::ResolveLocalMemberRefs()
 
                         if(RidFromToken(tkRef))
                         {
-                            MultiByteToWideChar(g_uCodePage,0,pMRD_szName,-1,wzUniBuf,dwUniBuf);
+                            minipal_convert_utf8_to_utf16(pMRD_szName,strlen(pMRD_szName)+1,(CHAR16_T*)wzUniBuf,dwUniBuf,0);
 
                             m_pEmitter->DefineMemberRef(tkRef, wzUniBuf, pMRD_pSig,
                                 pMRD_dwCSig, &tkMemberDef);
@@ -1205,7 +1206,7 @@ HRESULT Assembler::CreatePEFile(_In_ __nullterminated WCHAR *pwzOutputFilename)
     wzScopeName=&wzUniBuf[0];
     if(m_szScopeName[0]) // default: scope name = output file name
     {
-        MultiByteToWideChar(g_uCodePage,0,m_szScopeName,-1,wzScopeName,MAX_SCOPE_LENGTH);
+        minipal_convert_utf8_to_utf16(m_szScopeName,strlen(m_szScopeName)+1,(CHAR16_T*)wzScopeName,MAX_SCOPE_LENGTH,0);
     }
     else
     {
@@ -1705,12 +1706,12 @@ HRESULT Assembler::CreatePEFile(_In_ __nullterminated WCHAR *pwzOutputFilename)
         {
             m_pManifest->m_fMResNew[i] = FALSE;
             memset(sz,0,2048);
-            WideCharToMultiByte(CP_ACP,0,m_pManifest->m_wzMResName[i],-1,sz,2047,NULL,NULL);
+            minipal_convert_utf16_to_utf8((const CHAR16_T*)m_pManifest->m_wzMResName[i],u16_strlen(m_pManifest->m_wzMResName[i])+1,sz,2047,0);
             L = m_pManifest->m_dwMResSize[i];
             sizeread = 0;
             memcpy(ptr,&L,sizeof(DWORD));
             ptr += sizeof(DWORD);
-            if(fopen_s(&pFile,sz,"rb") == 0)
+            if(fopen_lp(&pFile,m_pManifest->m_wzMResName[i],W("rb")) == 0)
             {
                 sizeread = fread((void *)ptr,1,L,pFile);
                 fclose(pFile);
diff --git a/src/coreclr/ildasm/dasm.cpp b/src/coreclr/ildasm/dasm.cpp
index 68949122909291..27a3c006947a72 100644
--- a/src/coreclr/ildasm/dasm.cpp
+++ b/src/coreclr/ildasm/dasm.cpp
@@ -259,7 +259,7 @@ char* RstrA(unsigned n, unsigned codepage)
     WCHAR* wz = RstrW(n);
     // Unicode -> UTF-8
     memset(buff,0,sizeof(buff));
-    if(!WideCharToMultiByte(codepage,0,(LPCWSTR)wz,-1,buff,sizeof(buff),NULL,NULL))
+    if(!minipal_convert_utf16_to_utf8((const CHAR16_T*)wz,u16_strlen(wz)+1,buff,sizeof(buff),0))
         buff[0] = 0;
     return buff;
 }
@@ -3088,7 +3088,7 @@ char *DumpGenericPars(_Inout_updates_(SZSTRING_SIZE) char* szString, mdToken tok
         if (chName)
         {
             char* sz = (char*)(&wzUniBuf[UNIBUF_SIZE/2]);
-            WideCharToMultiByte(CP_UTF8,0,wzArgName,-1,sz,UNIBUF_SIZE,NULL,NULL);
+            minipal_convert_utf16_to_utf8((const CHAR16_T*)wzArgName,u16_strlen(wzArgName)+1,sz,UNIBUF_SIZE,0);
             szptr += sprintf_s(szptr,SZSTRING_REMAINING_SIZE(szptr),"%s",ProperName(sz));
         }
         CHECK_REMAINING_SIZE;
@@ -3156,7 +3156,7 @@ void DumpGenericParsCA(mdToken tok, void* GUICookie/*=NULL*/)
                     //if(u16_strlen(wzArgName) >= MAX_CLASSNAME_LENGTH)
                     //    wzArgName[MAX_CLASSNAME_LENGTH-1] = 0;
                     char* sz = (char*)(&wzUniBuf[UNIBUF_SIZE/2]);
-                    WideCharToMultiByte(CP_UTF8,0,wzArgName,-1,sz,UNIBUF_SIZE,NULL,NULL);
+                    minipal_convert_utf16_to_utf8((const CHAR16_T*)wzArgName,u16_strlen(wzArgName)+1,sz,UNIBUF_SIZE,0);
                     szptr += sprintf_s(szptr,SZSTRING_REMAINING_SIZE(szptr),"%s ",ProperName(sz));
                 }
                 else
@@ -3224,7 +3224,7 @@ void DumpGenericParsCA(mdToken tok, void* GUICookie/*=NULL*/)
                         if (chName > 0)
                         {
                             char* sz = (char*)(&wzUniBuf[UNIBUF_SIZE / 2]);
-                            WideCharToMultiByte(CP_UTF8, 0, wzArgName, -1, sz, UNIBUF_SIZE, NULL, NULL);
+                            minipal_convert_utf16_to_utf8((const CHAR16_T*)wzArgName, u16_strlen(wzArgName) + 1, sz, UNIBUF_SIZE, 0);
                             szptr += sprintf_s(szptr, SZSTRING_REMAINING_SIZE(szptr), "  %s", ProperName(sz));
                         }
                         else
@@ -6775,7 +6775,7 @@ void DumpMetaInfo(_In_ __nullterminated const WCHAR* pwzFileName, _In_opt_z_ con
                 int nLength = (int) strlen(pszObjFileName)+1;
                 pwzObjFileName = new WCHAR[nLength];
                 memset(pwzObjFileName,0,sizeof(WCHAR)*nLength);
-                MultiByteToWideChar(CP_UTF8,0,pszObjFileName,-1,pwzObjFileName,nLength);
+                minipal_convert_utf8_to_utf16(pszObjFileName,strlen(pszObjFileName)+1,(CHAR16_T*)pwzObjFileName,nLength,0);
             }
             DisplayFile((WCHAR*)pwzFileName, true, g_ulMetaInfoFilter, pwzObjFileName, DumpMI);
             g_pDisp->Release();
@@ -7214,9 +7214,9 @@ BOOL DumpFile()
     }
 
     memset(wzInputFileName,0,sizeof(WCHAR)*MAX_FILENAME_LENGTH);
-    MultiByteToWideChar(CP_UTF8,0,pszFilename,-1,wzInputFileName,MAX_FILENAME_LENGTH);
+    minipal_convert_utf8_to_utf16(pszFilename,strlen(pszFilename)+1,(CHAR16_T*)wzInputFileName,MAX_FILENAME_LENGTH,0);
     memset(szFilenameANSI,0,MAX_FILENAME_LENGTH*3);
-    WideCharToMultiByte(g_uConsoleCP,0,wzInputFileName,-1,szFilenameANSI,MAX_FILENAME_LENGTH*3,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)wzInputFileName,u16_strlen(wzInputFileName)+1,szFilenameANSI,MAX_FILENAME_LENGTH*3,0);
         fSuccess = g_pPELoader->open(wzInputFileName);
 
     if (fSuccess == FALSE)
@@ -7566,7 +7566,7 @@ BOOL DumpFile()
         {
             WCHAR wzResFileName[2048], *pwc;
             memset(wzResFileName,0,sizeof(wzResFileName));
-            MultiByteToWideChar(CP_UTF8,0,g_szOutputFile,-1,wzResFileName,2048);
+            minipal_convert_utf8_to_utf16(g_szOutputFile,strlen(g_szOutputFile)+1,(CHAR16_T*)wzResFileName,2048,0);
             pwc = (WCHAR*)u16_strrchr(wzResFileName,L'.');
             if(pwc == NULL) pwc = &wzResFileName[u16_strlen(wzResFileName)];
             wcscpy_s(pwc, 2048 - (pwc - wzResFileName), L".res");
diff --git a/src/coreclr/ildasm/dis.cpp b/src/coreclr/ildasm/dis.cpp
index 04d95e3e01781c..e89547335044cc 100644
--- a/src/coreclr/ildasm/dis.cpp
+++ b/src/coreclr/ildasm/dis.cpp
@@ -91,7 +91,7 @@ OPCODE DecodeOpcode(const BYTE *pCode, DWORD *pdwLen)
 WCHAR* UtfToUnicode(_In_ __nullterminated const char* sz)
 {
     WCHAR* wz = wzUniBuf;
-    if (MultiByteToWideChar(CP_UTF8,0,sz,-1,wz,UNIBUF_SIZE/2) == 0)
+    if (minipal_convert_utf8_to_utf16(sz,strlen(sz)+1,(CHAR16_T*)wz,UNIBUF_SIZE/2,0) == 0)
     {
         wz[UNIBUF_SIZE/2 - 1] = 0;
     }
@@ -100,7 +100,7 @@ WCHAR* UtfToUnicode(_In_ __nullterminated const char* sz)
 char* UnicodeToAnsi(_In_ __nullterminated const WCHAR* wz)
 {
     char* sz = (char*)(&wzUniBuf[UNIBUF_SIZE/2]);
-    if (WideCharToMultiByte(g_uConsoleCP,0,wz,-1,sz,UNIBUF_SIZE,NULL,NULL) == 0)
+    if (minipal_convert_utf16_to_utf8((const CHAR16_T*)wz,u16_strlen(wz)+1,sz,UNIBUF_SIZE,0) == 0)
     {
         sz[UNIBUF_SIZE - 1] = 0;
     }
@@ -109,7 +109,7 @@ char* UnicodeToAnsi(_In_ __nullterminated const WCHAR* wz)
 WCHAR* AnsiToUnicode(_In_ __nullterminated const char* sz)
 {
     WCHAR* wz = wzUniBuf;
-    if (MultiByteToWideChar(g_uConsoleCP,0,sz,-1,wz,UNIBUF_SIZE/2) == 0)
+    if (minipal_convert_utf8_to_utf16(sz,strlen(sz)+1,(CHAR16_T*)wz,UNIBUF_SIZE/2,0) == 0)
     {
         wz[UNIBUF_SIZE/2 - 1] = 0;
     }
@@ -118,7 +118,7 @@ WCHAR* AnsiToUnicode(_In_ __nullterminated const char* sz)
 char* UnicodeToUtf(_In_ __nullterminated const WCHAR* wz)
 {
     char* sz = (char*)(&wzUniBuf[UNIBUF_SIZE/2]);
-    if (WideCharToMultiByte(CP_UTF8,0,wz,-1,sz,UNIBUF_SIZE,NULL,NULL) == 0)
+    if (minipal_convert_utf16_to_utf8((const CHAR16_T*)wz,u16_strlen(wz)+1,sz,UNIBUF_SIZE,0) == 0)
     {
         sz[UNIBUF_SIZE - 1] = 0;
     }
@@ -727,7 +727,7 @@ char* DumpUnicodeString(void* GUICookie,
     szStr = new char[cbString*3 + 5];
     memset(szStr,0,cbString*3 + 5);
 
-    WideCharToMultiByte(CP_UTF8,0,pszString,cbString,&szStr[0],cbString*3,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)pszString,cbString,&szStr[0],cbString*3,0);
     L = (unsigned)strlen(szStr);
 
     szStr[L] = 0;
@@ -1069,7 +1069,7 @@ BOOL Disassemble(IMDInternalImport *pImport, BYTE *ILHeader, void *GUICookie, md
                     {
                         wcscpy_s(wzWasFileName,2048,wzFileName);
                         memset(szFileName,0,2048);
-                        WideCharToMultiByte(CP_UTF8,0,wzFileName,-1,szFileName,2048,NULL,NULL);
+                        minipal_convert_utf16_to_utf8((const CHAR16_T*)wzFileName,u16_strlen(wzFileName)+1,szFileName,2048,0);
                         if(fShowSource)
                         {
                             if(pFile) fclose(pFile);
diff --git a/src/coreclr/ildasm/dman.cpp b/src/coreclr/ildasm/dman.cpp
index 240f4a42e6f2aa..7ca18ae832a2a8 100644
--- a/src/coreclr/ildasm/dman.cpp
+++ b/src/coreclr/ildasm/dman.cpp
@@ -74,7 +74,7 @@ void DumpFiles(void* GUICookie)
                         int L = ulNameLen*3+3;
                         char* sz = new char[L];
                         memset(sz,0,L);
-                        WideCharToMultiByte(CP_UTF8,0,rFile[ix].name,-1,sz,L,NULL,NULL);
+                        minipal_convert_utf16_to_utf8((const CHAR16_T*)rFile[ix].name,u16_strlen(rFile[ix].name)+1,sz,L,0);
                         strcpy_s(szptr,SZSTRING_REMAINING_SIZE(szptr), ANCHORPT(ProperName(sz),rFileTok[ix]));
                         VDELETE(sz);
                     }
@@ -126,7 +126,7 @@ void DumpScope(void* GUICookie)
             UINT32 L = (UINT32)u16_strlen(scopeName)*3+3;
             char* sz = new char[L];
             memset(sz,0,L);
-            WideCharToMultiByte(CP_UTF8,0,scopeName,-1,sz,L,NULL,NULL);
+            minipal_convert_utf16_to_utf8((const CHAR16_T*)scopeName,u16_strlen(scopeName)+1,sz,L,0);
             sprintf_s(szString,SZSTRING_SIZE,"%s%s %s",g_szAsmCodeIndent,KEYWORD(".module"),ProperName(sz));
             VDELETE(sz);
         }
@@ -232,7 +232,7 @@ void DumpAssembly(void* GUICookie, BOOL fFullDump)
             {
                 char* sz = new char[3*ulNameLen+3];
                 memset(sz,0,3*ulNameLen+3);
-                WideCharToMultiByte(CP_UTF8,0,wzName,-1,sz,3*ulNameLen+3,NULL,NULL);
+                minipal_convert_utf16_to_utf8((const CHAR16_T*)wzName,u16_strlen(wzName)+1,sz,3*ulNameLen+3,0);
                 strcat_s(szString,SZSTRING_SIZE,ANCHORPT(ProperName(sz),tkAsm));
                 VDELETE(sz);
             }
@@ -354,7 +354,7 @@ void DumpAssemblyRefs(void* GUICookie)
                     {
                         char* sz = new char[3*ulNameLen+32];
                         memset(sz,0,3*ulNameLen+3);
-                        WideCharToMultiByte(CP_UTF8,0,rAsmRef[ix].name,-1,sz,3*ulNameLen+3,NULL,NULL);
+                        minipal_convert_utf16_to_utf8((const CHAR16_T*)rAsmRef[ix].name,u16_strlen(rAsmRef[ix].name)+1,sz,3*ulNameLen+3,0);
                         // check for name duplication and introduce alias if needed
                         for(ixx = 0; ixx < ix; ixx++)
                         {
@@ -424,7 +424,7 @@ void DumpComTypeFQN(
     UINT32 L = (UINT32)u16_strlen(pCTD->wzName)*3+3;
     char* sz = new char[L];
     memset(sz,0,L);
-    WideCharToMultiByte(CP_UTF8,0,pCTD->wzName,-1,sz,L,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)pCTD->wzName,u16_strlen(pCTD->wzName)+1,sz,L,0);
     strcat_s(szName, SZSTRING_SIZE, JUMPPT(ProperName(sz), pCTD->tkComTypeTok));
     VDELETE(sz);
 }
@@ -447,7 +447,7 @@ void DumpImplementation(mdToken tkImplementation,
                     UINT32 L = (UINT32)u16_strlen(rFile[i].name)*3+3;
                     char* sz = new char[L];
                     memset(sz,0,L);
-                    WideCharToMultiByte(CP_UTF8,0,rFile[i].name,-1,sz,L,NULL,NULL);
+                    minipal_convert_utf16_to_utf8((const CHAR16_T*)rFile[i].name,u16_strlen(rFile[i].name)+1,sz,L,0);
                     sprintf_s(szString,SZSTRING_SIZE,"%s%s %s",g_szAsmCodeIndent,KEYWORD(".file"),
                             JUMPPT(ProperName(sz),tkImplementation));
                     VDELETE(sz);
@@ -467,7 +467,7 @@ void DumpImplementation(mdToken tkImplementation,
                     UINT32 L = (UINT32)u16_strlen(rAsmRef[i].name)*3+3;
                     char* sz = new char[L];
                     memset(sz,0,L);
-                    WideCharToMultiByte(CP_UTF8,0,rAsmRef[i].name,-1,sz,L,NULL,NULL);
+                    minipal_convert_utf16_to_utf8((const CHAR16_T*)rAsmRef[i].name,u16_strlen(rAsmRef[i].name)+1,sz,L,0);
                     sprintf_s(szString,SZSTRING_SIZE,"%s%s %s",g_szAsmCodeIndent,KEYWORD(".assembly extern"),
                             JUMPPT(ProperName(sz),tkImplementation));
                     VDELETE(sz);
@@ -513,7 +513,7 @@ void DumpComType(LocalComTypeDescr* pCTD,
         UINT32 L = (UINT32)u16_strlen(pCTD->wzName)*3+3;
         char* sz = new char[L];
         memset(sz,0,L);
-        WideCharToMultiByte(CP_UTF8,0,pCTD->wzName,-1,sz,L,NULL,NULL);
+        minipal_convert_utf16_to_utf8((const CHAR16_T*)pCTD->wzName,u16_strlen(pCTD->wzName)+1,sz,L,0);
         strcpy_s(pc,SZSTRING_REMAINING_SIZE(pc),ANCHORPT(ProperName(sz),pCTD->tkComTypeTok));
         VDELETE(sz);
     }
@@ -778,7 +778,7 @@ void DumpManifestResources(void* GUICookie)
 
             static WCHAR wzFileName[2048];
 
-            MultiByteToWideChar(CP_UTF8,0,g_szOutputFile,-1,wzFileName,2048);
+            minipal_convert_utf8_to_utf16(g_szOutputFile,strlen(g_szOutputFile)+1,(CHAR16_T*)wzFileName,2048,0);
             wzName = (WCHAR*)u16_strrchr(wzFileName,DIRECTORY_SEPARATOR_CHAR_W);
 #ifdef HOST_WINDOWS
             if(wzName == NULL) wzName = (WCHAR*)u16_strrchr(wzFileName,':');
@@ -835,7 +835,7 @@ void DumpManifestResources(void* GUICookie)
                     char* pc = szString + strlen(szString);
                     wzName[ulNameLen]=0;
 
-                    WideCharToMultiByte(CP_UTF8,0,wzName,-1,sz,sizeof(sz),NULL,NULL);
+                    minipal_convert_utf16_to_utf8((const CHAR16_T*)wzName,u16_strlen(wzName)+1,sz,sizeof(sz),0);
                     strcpy_s(pc,SZSTRING_REMAINING_SIZE(pc),ProperName(sz));
 
                     // get rid of invalid characters and reserved names
@@ -890,7 +890,7 @@ void DumpManifestResources(void* GUICookie)
                     if(fAlias)
                     {
                         // update sz with the aliased name and print the 'as' keyword
-                        if (WideCharToMultiByte(CP_UTF8, 0, wzName, -1, sz, sizeof(sz), NULL, NULL) == 0)
+                        if (minipal_convert_utf16_to_utf8((const CHAR16_T*)wzName, u16_strlen(wzName) + 1, sz, sizeof(sz), 0) == 0)
                         {
                             sz[sizeof(sz) - 1] = 0;
                         }
diff --git a/src/coreclr/ildasm/windasm.cpp b/src/coreclr/ildasm/windasm.cpp
index 6e33c86ceeed0a..26cf2baae862e7 100644
--- a/src/coreclr/ildasm/windasm.cpp
+++ b/src/coreclr/ildasm/windasm.cpp
@@ -136,7 +136,7 @@ char* EqualOrColon(_In_ __nullterminated char* szArg)
 void GetInputFileFullPath()
 {
 #ifdef TARGET_UNIX
-    MultiByteToWideChar(g_uConsoleCP, 0, g_szInputFile, -1, g_wszFullInputFile, MAX_PATH + 1);
+    minipal_convert_utf8_to_utf16(g_szInputFile, strlen(g_szInputFile) + 1, (CHAR16_T*)g_wszFullInputFile, MAX_PATH + 1, 0);
 #else
     // We need the input file's full path to make uses of it later, despite changing CurrentDirectory
 
@@ -144,7 +144,7 @@ void GetInputFileFullPath()
     DWORD len = (DWORD) strlen(g_szInputFile) + 16;
     WCHAR* wzArg = new WCHAR[len];
     memset(wzArg, 0, len * sizeof(WCHAR));
-    MultiByteToWideChar(g_uConsoleCP, 0, g_szInputFile, -1, wzArg, len);
+    minipal_convert_utf8_to_utf16(g_szInputFile, strlen(g_szInputFile) + 1, (CHAR16_T*)wzArg, len, 0);
 
     // Get the full path
     len = GetFullPathName(wzArg, MAX_PATH, g_wszFullInputFile, NULL);
@@ -429,7 +429,7 @@ int ParseCmdLineW(int argc, _In_ __nullterminated wchar_t* argv[], _Out_ char**
     for(int i=1; i < argc; i++)
     {
         memset(szArg,0,2048);
-        WideCharToMultiByte(CP_UTF8,0,argv[i],-1,szArg,2048,NULL,NULL);
+        minipal_convert_utf16_to_utf8((const CHAR16_T*)argv[i],u16_strlen(argv[i])+1,szArg,2048,0);
         if((ret = ProcessOneArg(szArg,ppszObjFileName)) != 0) break;
     }
     VDELETE(szArg);
@@ -506,7 +506,7 @@ int main(int argc, char* argv[])
         g_fHideFOA = FALSE;
         g_fHidePrivScope = FALSE;
     }
-    g_uConsoleCP = GetConsoleOutputCP();
+    g_uConsoleCP = CP_UTF8;
 
     if(iCommandLineParsed)
     {
diff --git a/src/coreclr/inc/mdfileformat.h b/src/coreclr/inc/mdfileformat.h
index 85dbb6c1be3104..13e24f21a7a110 100644
--- a/src/coreclr/inc/mdfileformat.h
+++ b/src/coreclr/inc/mdfileformat.h
@@ -198,13 +198,13 @@ struct STORAGESTREAM
     }
     inline LPCWSTR GetName(__inout_ecount (iMaxSize) LPWSTR szName, int iMaxSize)
     {
-        VERIFY(::MultiByteToWideChar(CP_ACP, 0, rcName, -1, szName, iMaxSize));
+        VERIFY(minipal_convert_utf8_to_utf16(rcName, strlen(rcName) + 1, (CHAR16_T*)szName, iMaxSize, 0));
         return (szName);
     }
     inline void SetName(LPCWSTR szName)
     {
-        int size;
-        size = WideCharToMultiByte(CP_ACP, 0, szName, -1, rcName, MAXSTREAMNAME, 0, 0);
+        size_t size;
+        size = minipal_convert_utf16_to_utf8((const CHAR16_T*)szName, u16_strlen(szName) + 1, rcName, MAXSTREAMNAME, 0);
         _ASSERTE(size > 0);
     }
 
diff --git a/src/coreclr/inc/utilcode.h b/src/coreclr/inc/utilcode.h
index fa397c30c9c4fa..e43efebdb15d17 100644
--- a/src/coreclr/inc/utilcode.h
+++ b/src/coreclr/inc/utilcode.h
@@ -39,6 +39,7 @@ using std::nothrow;
 #include <minipal/guid.h>
 #include <minipal/log.h>
 #include <minipal/ospagesize.h>
+#include <minipal/utf8.h>
 #include <dn-u16.h>
 
 #include "clrnt.h"
@@ -206,28 +207,18 @@ typedef LPSTR   LPUTF8;
 // ptrname will be deleted when it goes out of scope.
 #define MAKE_UTF8PTR_FROMWIDE_NOTHROW(ptrname, widestr) \
     CQuickBytes __qb##ptrname; \
-    int __l##ptrname = (int)u16_strlen(widestr); \
+    size_t __lsrc##ptrname = u16_strlen(widestr) + 1; \
+    size_t __l##ptrname = 0; \
     LPUTF8 ptrname = NULL; \
-    if (__l##ptrname <= MAKE_MAX_LENGTH) { \
-        __l##ptrname = (int)((__l##ptrname + 1) * 2 * sizeof(char)); \
+    if (__lsrc##ptrname <= MAKE_MAX_LENGTH) { \
+        __l##ptrname = __lsrc##ptrname * 2; \
         ptrname = (LPUTF8) __qb##ptrname.AllocNoThrow(__l##ptrname); \
     } \
     if (ptrname) { \
-        INT32 __lresult##ptrname=WideCharToMultiByte(CP_UTF8, 0, widestr, -1, ptrname, __l##ptrname-1, NULL, NULL); \
-        DWORD __dwCaptureLastError##ptrname = ::GetLastError(); \
-        if ((__lresult##ptrname==0) && (((LPCWSTR)widestr)[0] != W('\0'))) { \
-            if (__dwCaptureLastError##ptrname==ERROR_INSUFFICIENT_BUFFER) { \
-                INT32 __lsize##ptrname=WideCharToMultiByte(CP_UTF8, 0, widestr, -1, NULL, 0, NULL, NULL); \
-                ptrname = (LPSTR) __qb##ptrname .AllocNoThrow(__lsize##ptrname); \
-                if (ptrname) { \
-                    if (WideCharToMultiByte(CP_UTF8, 0, widestr, -1, ptrname, __lsize##ptrname, NULL, NULL) != 0) { \
-                        ptrname[__l##ptrname] = 0; \
-                    } else { \
-                        ptrname = NULL; \
-                    } \
-                } \
-            } \
-            else { \
+        if (minipal_convert_utf16_to_utf8((const CHAR16_T*)(widestr), __lsrc##ptrname, ptrname, __l##ptrname, 0) == 0) { \
+            __l##ptrname = minipal_get_length_utf16_to_utf8((const CHAR16_T*)(widestr), __lsrc##ptrname, 0); \
+            ptrname = (LPUTF8) __qb##ptrname.AllocNoThrow(__l##ptrname); \
+            if (ptrname && minipal_convert_utf16_to_utf8((const CHAR16_T*)(widestr), __lsrc##ptrname, ptrname, __l##ptrname, 0) == 0) { \
                 ptrname = NULL; \
             } \
         } \
@@ -237,21 +228,23 @@ typedef LPSTR   LPUTF8;
 
 #define MAKE_WIDEPTR_FROMUTF8N_NOTHROW(ptrname, utf8str, n8chrs) \
     CQuickBytes __qb##ptrname; \
-    int __l##ptrname; \
+    size_t __n##ptrname = (size_t)(n8chrs); \
     LPWSTR ptrname = NULL; \
-    __l##ptrname = MultiByteToWideChar(CP_UTF8, 0, utf8str, n8chrs, 0, 0); \
-    if (__l##ptrname <= MAKE_MAX_LENGTH) { \
-        ptrname = (LPWSTR) __qb##ptrname.AllocNoThrow((__l##ptrname+1)*sizeof(WCHAR));  \
-        if (ptrname) { \
-            if (MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8str, n8chrs, ptrname, __l##ptrname) != 0) { \
-                ptrname[__l##ptrname] = 0; \
-            } else { \
-                ptrname = NULL; \
+    if (__n##ptrname != 0) { \
+        size_t __l##ptrname = minipal_get_length_utf8_to_utf16(utf8str, __n##ptrname, 0); \
+        if (__l##ptrname <= MAKE_MAX_LENGTH) { \
+            ptrname = (LPWSTR) __qb##ptrname.AllocNoThrow((__l##ptrname+1)*sizeof(WCHAR));  \
+            if (ptrname) { \
+                if (minipal_convert_utf8_to_utf16(utf8str, __n##ptrname, (CHAR16_T*)ptrname, __l##ptrname, MINIPAL_MB_NO_REPLACE_INVALID_CHARS) != 0) { \
+                    ptrname[__l##ptrname] = 0; \
+                } else { \
+                    ptrname = NULL; \
+                } \
             } \
         } \
     }
 
-#define MAKE_WIDEPTR_FROMUTF8_NOTHROW(ptrname, utf8str)   MAKE_WIDEPTR_FROMUTF8N_NOTHROW(ptrname, utf8str, -1)
+#define MAKE_WIDEPTR_FROMUTF8_NOTHROW(ptrname, utf8str)   MAKE_WIDEPTR_FROMUTF8N_NOTHROW(ptrname, utf8str, (utf8str) != NULL ? strlen(utf8str) + 1 : 0)
 
 const SIZE_T MaxSigned32BitDecString = ARRAY_SIZE("-2147483648") - 1;
 const SIZE_T MaxUnsigned32BitDecString = ARRAY_SIZE("4294967295") - 1;
diff --git a/src/coreclr/jit/helperexpansion.cpp b/src/coreclr/jit/helperexpansion.cpp
index 461b6dccbd5463..b26dba3e0f9346 100644
--- a/src/coreclr/jit/helperexpansion.cpp
+++ b/src/coreclr/jit/helperexpansion.cpp
@@ -1717,21 +1717,22 @@ bool Compiler::fgVNBasedIntrinsicExpansionForCall_ReadUtf8(BasicBlock** pBlock,
     const int MaxU8BufferSizeInBytes = 256;
     uint8_t   bufferU8[MaxU8BufferSizeInBytes];
 
-    const int srcLenU8 = (int)minipal_convert_utf16_to_utf8((const CHAR16_T*)bufferU16, srcLenCnsU16, (char*)bufferU8,
-                                                            MaxU8BufferSizeInBytes, 0);
-    if (srcLenU8 <= 0)
+    const size_t convertedLen = minipal_convert_utf16_to_utf8((const CHAR16_T*)bufferU16, srcLenCnsU16, (char*)bufferU8,
+                                                              MaxU8BufferSizeInBytes, 0);
+    if (convertedLen == 0)
     {
         // E.g. output buffer is too small
-        JITDUMP("ReadUtf8: minipal_convert_utf16_to_utf8 returned <= 0\n")
+        JITDUMP("ReadUtf8: minipal_convert_utf16_to_utf8 returned 0\n")
         return false;
     }
 
-    // The API is expected to return [1..MaxU8BufferSizeInBytes] real length of the UTF-8 value
-    // stored in bufferU8
-    assert((unsigned)srcLenU8 <= MaxU8BufferSizeInBytes);
+    // Narrow for the unsigned JIT helpers below. minipal_convert_utf16_to_utf8 cannot write
+    // more than MaxU8BufferSizeInBytes into the buffer.
+    const unsigned srcLenU8 = (unsigned)convertedLen;
+    assert(srcLenU8 <= (unsigned)MaxU8BufferSizeInBytes);
 
     // Now that we know the exact UTF8 buffer length we can check if it's unrollable
-    if (srcLenU8 > (int)getUnrollThreshold(UnrollKind::Memcpy))
+    if (srcLenU8 > getUnrollThreshold(UnrollKind::Memcpy))
     {
         JITDUMP("ReadUtf8: srcLenU8 is out of unrollable range\n")
         return false;
diff --git a/src/coreclr/jit/utils.cpp b/src/coreclr/jit/utils.cpp
index 2ae032145ad851..790d03d9237497 100644
--- a/src/coreclr/jit/utils.cpp
+++ b/src/coreclr/jit/utils.cpp
@@ -24,6 +24,7 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 #include "opcode.h"
 #include "jitstd/algorithm.h"
 #include "minipal/time.h"
+#include "minipal/utf8.h"
 
 /*****************************************************************************/
 
@@ -3934,13 +3935,10 @@ class Utf16String
 public:
     Utf16String(const char* str)
     {
-        int strBufferSize = MultiByteToWideChar(CP_UTF8, 0, str, -1, nullptr, 0);
-        if (strBufferSize == 0)
-        {
-            return;
-        }
+        size_t strLength     = strlen(str) + 1;
+        size_t strBufferSize = minipal_get_length_utf8_to_utf16(str, strLength, 0);
 
-        if (static_cast<size_t>(strBufferSize) > bufferSize)
+        if (strBufferSize > bufferSize)
         {
             m_pBuffer = new WCHAR[strBufferSize];
         }
@@ -3949,15 +3947,7 @@ class Utf16String
             m_pBuffer = m_bufferUnsafe;
         }
 
-        if (MultiByteToWideChar(CP_UTF8, 0, str, -1, m_pBuffer, strBufferSize) == 0)
-        {
-            if (m_pBuffer != m_bufferUnsafe)
-            {
-                delete[] m_pBuffer;
-            }
-
-            m_pBuffer = nullptr;
-        }
+        minipal_convert_utf8_to_utf16(str, strLength, (CHAR16_T*)m_pBuffer, strBufferSize, 0);
     }
 
     ~Utf16String()
diff --git a/src/coreclr/md/compiler/custattr_import.cpp b/src/coreclr/md/compiler/custattr_import.cpp
index 57465fb936ce10..81ab95b96ae107 100644
--- a/src/coreclr/md/compiler/custattr_import.cpp
+++ b/src/coreclr/md/compiler/custattr_import.cpp
@@ -34,15 +34,17 @@ STDMETHODIMP RegMeta::GetCustomAttributeByName( // S_OK or error.
     HRESULT     hr;                     // A result.
 
     LPUTF8      szName;                 // Name in UFT8.
-    int         iLen;                   // A length.
+    size_t      cchName;                // Length of the name, including the terminator.
+    size_t      iLen;                   // A length.
     CMiniMdRW   *pMiniMd = NULL;
 
     LOCKREAD();
     pMiniMd = &(m_pStgdb->m_MiniMd);
 
-    iLen = WideCharToMultiByte(CP_UTF8,0, wzName,-1, NULL,0, 0,0);
+    cchName = u16_strlen(wzName) + 1;
+    iLen = minipal_get_length_utf16_to_utf8((const CHAR16_T*)wzName, cchName, 0);
     szName = (LPUTF8)_alloca(iLen);
-    VERIFY(WideCharToMultiByte(CP_UTF8,0, wzName,-1, szName,iLen, 0,0));
+    VERIFY(minipal_convert_utf16_to_utf8((const CHAR16_T*)wzName, cchName, szName, iLen, 0));
 
     hr = ImportHelper::GetCustomAttributeByName(pMiniMd, tkObj, szName, ppData, pcbData);
 
diff --git a/src/coreclr/md/compiler/disp.cpp b/src/coreclr/md/compiler/disp.cpp
index d1d8ad6e066a96..05f48690810960 100644
--- a/src/coreclr/md/compiler/disp.cpp
+++ b/src/coreclr/md/compiler/disp.cpp
@@ -629,11 +629,12 @@ Disp::SetOption(
         }
         else
         {
-            INT32 len = WideCharToMultiByte(CP_UTF8, 0, V_BSTR(pvalue), -1, NULL, 0, NULL, NULL);
+            size_t cchVersion = u16_strlen(V_BSTR(pvalue)) + 1;
+            size_t len = minipal_get_length_utf16_to_utf8((const CHAR16_T*)V_BSTR(pvalue), cchVersion, 0);
             m_OptionValue.m_RuntimeVersion = new (nothrow) char[len];
             if (m_OptionValue.m_RuntimeVersion == NULL)
             IfFailGo(E_INVALIDARG);
-            WideCharToMultiByte(CP_UTF8, 0, V_BSTR(pvalue), -1, m_OptionValue.m_RuntimeVersion, len, NULL, NULL);
+            minipal_convert_utf16_to_utf8((const CHAR16_T*)V_BSTR(pvalue), cchVersion, m_OptionValue.m_RuntimeVersion, len, 0);
         }
     }
     else if (optionid == MetaDataInitialSize)
diff --git a/src/coreclr/md/compiler/import.cpp b/src/coreclr/md/compiler/import.cpp
index 098223ebef4094..6e8fff28ac22c9 100644
--- a/src/coreclr/md/compiler/import.cpp
+++ b/src/coreclr/md/compiler/import.cpp
@@ -2978,7 +2978,7 @@ HRESULT RegMeta::GetVersionString(    // S_OK or error.
 
     REGMETA_POSSIBLE_INTERNAL_POINTER_EXPOSED();
 
-    DWORD       cch;                    // Length of WideChar string.
+    size_t      cch;                    // Length of WideChar string.
     LPCSTR      pVer;                   // Pointer to version string.
 
     LOCKREAD();
@@ -2988,17 +2988,24 @@ HRESULT RegMeta::GetVersionString(    // S_OK or error.
         // For convenience, get a pointer to the version string.
         // @todo: get from alternate locations when there is no STOREAGESIGNATURE.
         pVer = reinterpret_cast<const char*>(reinterpret_cast<const STORAGESIGNATURE*>(m_pStgdb->m_pvMd)->pVersion);
-        // Attempt to convert into caller's buffer.
-        cch = MultiByteToWideChar(CP_UTF8,0, pVer,-1, pwzBuf,cchBufSize);
-        // Did the string fit?
-        if (cch == 0)
-        {   // No, didn't fit.  Find out space required.
-            cch = MultiByteToWideChar(CP_UTF8,0, pVer,-1, pwzBuf,0);
-            // NUL terminate string.
-            if (cchBufSize > 0)
+        size_t cchVer = strlen(pVer) + 1;
+        if (cchBufSize == 0)
+        {   // Only the space required.
+            cch = minipal_get_length_utf8_to_utf16(pVer, cchVer, 0);
+        }
+        else
+        {
+            // Attempt to convert into caller's buffer.
+            cch = minipal_convert_utf8_to_utf16(pVer, cchVer, (CHAR16_T*)pwzBuf, cchBufSize, 0);
+            // Did the string fit?
+            if (cch == 0)
+            {   // No, didn't fit.  Find out space required.
+                cch = minipal_get_length_utf8_to_utf16(pVer, cchVer, 0);
+                // NUL terminate string.
                 pwzBuf[cchBufSize-1] = W('\0');
-            // Truncation return code.
-            hr = CLDB_S_TRUNCATION;
+                // Truncation return code.
+                hr = CLDB_S_TRUNCATION;
+            }
         }
     }
     else
@@ -3009,7 +3016,7 @@ HRESULT RegMeta::GetVersionString(    // S_OK or error.
     }
 
     if (pchBufSize)
-        *pchBufSize = cch;
+        *pchBufSize = (DWORD)cch;
 
 ErrExit:
     return hr;
diff --git a/src/coreclr/md/enc/metamodelrw.cpp b/src/coreclr/md/enc/metamodelrw.cpp
index 0fc2b8b041d817..ea568f67d22724 100644
--- a/src/coreclr/md/enc/metamodelrw.cpp
+++ b/src/coreclr/md/enc/metamodelrw.cpp
@@ -3819,7 +3819,8 @@ CMiniMdRW::Impl_GetStringW(
                              ULONG *pcchBuffer)
 {
     LPCSTR  szString;       // Single byte version.
-    int     iSize;          // Size of resulting string, in wide chars.
+    size_t  cchString;      // Length of the single byte version, including the terminator.
+    size_t  iSize;          // Size of resulting string, in wide chars.
     HRESULT hr = NOERROR;
 
     IfFailGo(getString(ix, &szString));
@@ -3833,18 +3834,19 @@ CMiniMdRW::Impl_GetStringW(
             *pcchBuffer = 0;
         goto ErrExit;
     }
-    if (!(iSize=::MultiByteToWideChar(CP_UTF8, 0, szString, -1, szOut, cchBuffer)))
+    cchString = strlen(szString) + 1;
+    if (cchBuffer == 0)
+        iSize = minipal_get_length_utf8_to_utf16(szString, cchString, 0);
+    else
+        iSize = szOut != NULL ? minipal_convert_utf8_to_utf16(szString, cchString, (CHAR16_T*)szOut, cchBuffer, 0) : 0;
+    if (iSize == 0)
     {
-        // What was the problem?
-        DWORD dwNT = GetLastError();
-
-        // Not truncation?
-        if (dwNT != ERROR_INSUFFICIENT_BUFFER)
-            IfFailGo(HRESULT_FROM_NT(dwNT));
-
         // Truncation error; get the size required.
         if (pcchBuffer)
-            *pcchBuffer = ::MultiByteToWideChar(CP_UTF8, 0, szString, -1, NULL, 0);
+        {
+            size_t cchNeeded = minipal_get_length_utf8_to_utf16(szString, cchString, 0);
+            *pcchBuffer = (ULONG)cchNeeded;
+        }
 
         if ((szOut != NULL) && (cchBuffer > 0))
         {   // null-terminate the truncated output string
@@ -3855,7 +3857,7 @@ CMiniMdRW::Impl_GetStringW(
         goto ErrExit;
     }
     if (pcchBuffer)
-        *pcchBuffer = iSize;
+        *pcchBuffer = (ULONG)iSize;
 
 ErrExit:
     return hr;
diff --git a/src/coreclr/md/enc/rwutil.cpp b/src/coreclr/md/enc/rwutil.cpp
index 27dd972cd056d9..33ac00b8c66aea 100644
--- a/src/coreclr/md/enc/rwutil.cpp
+++ b/src/coreclr/md/enc/rwutil.cpp
@@ -164,18 +164,10 @@ Unicode2UTF(
     LPUTF8  szDst,  // Buffer for the output UTF8 string.
     int     cbDst)  // Size of the buffer for UTF8 string.
 {
-    int cchSrc = (int)u16_strlen(wszSrc);
-    int cchRet;
-
-    cchRet = WideCharToMultiByte(
-        CP_UTF8,
-        0,
-        wszSrc,
-        cchSrc + 1,
-        szDst,
-        cbDst,
-        NULL,
-        NULL);
+    size_t cchSrc = u16_strlen(wszSrc);
+    size_t cchRet;
+
+    cchRet = minipal_convert_utf16_to_utf8((const CHAR16_T*)wszSrc, cchSrc + 1, szDst, cbDst, 0);
 
     if (cchRet == 0)
     {
diff --git a/src/coreclr/md/enc/stgtiggerstorage.cpp b/src/coreclr/md/enc/stgtiggerstorage.cpp
index 22551616b43508..1f89a48bb44891 100644
--- a/src/coreclr/md/enc/stgtiggerstorage.cpp
+++ b/src/coreclr/md/enc/stgtiggerstorage.cpp
@@ -358,11 +358,13 @@ TiggerStorage::GetStreamSaveSize(
     UINT32  cbDataSize,         // Size of data to go into stream.
     UINT32 *pcbSaveSize)        // Return data size plus stream overhead.
 {
+    size_t cbName;                 // Converted stream name length.
     UINT32 cbTotalSize;            // Add up each element.
 
     // Find out how large the name will be.
-    cbTotalSize = ::WideCharToMultiByte(CP_ACP, 0, szStreamName, -1, 0, 0, 0, 0);
-    _ASSERTE(cbTotalSize != 0);
+    cbName = minipal_get_length_utf16_to_utf8((const CHAR16_T*)szStreamName, u16_strlen(szStreamName) + 1, 0);
+    _ASSERTE(cbName != 0);
+    cbTotalSize = (UINT32)cbName;
 
     // Add the size of the stream header minus the static name array.
     cbTotalSize += sizeof(STORAGESTREAM) - MAXSTREAMNAME;
@@ -445,7 +447,7 @@ HRESULT STDMETHODCALLTYPE TiggerStorage::CreateStream(
 {
 #ifdef FEATURE_METADATA_PERSISTENCE
     char        rcStream[MAXSTREAMNAME];// For converted name.
-    VERIFY(WideCharToMultiByte(CP_ACP, 0, pwcsName, -1, rcStream, sizeof(rcStream), 0, 0));
+    VERIFY(minipal_convert_utf16_to_utf8((const CHAR16_T*)pwcsName, u16_strlen(pwcsName) + 1, rcStream, sizeof(rcStream), 0));
     return (CreateStream(rcStream, grfMode, reserved1, reserved2, ppstm));
 #else
     return E_NOTIMPL;
@@ -641,7 +643,7 @@ HRESULT STDMETHODCALLTYPE TiggerStorage::OpenStream(
     HRESULT     hr;
 
     // Convert the name for internal use.
-    VERIFY(::WideCharToMultiByte(CP_ACP, 0, szStream, -1, rcName, sizeof(rcName), 0, 0));
+    VERIFY(minipal_convert_utf16_to_utf8((const CHAR16_T*)szStream, u16_strlen(szStream) + 1, rcName, sizeof(rcName), 0));
 
     // Look for the stream which must be found for this to work.  Note that
     // this error is explicitly not posted as an error object since unfound streams
diff --git a/src/coreclr/md/runtime/metamodelro.cpp b/src/coreclr/md/runtime/metamodelro.cpp
index 2f3638c331957c..ca327f28a49b4a 100644
--- a/src/coreclr/md/runtime/metamodelro.cpp
+++ b/src/coreclr/md/runtime/metamodelro.cpp
@@ -102,7 +102,8 @@ CMiniMd::Impl_GetStringW(
     ULONG *pcchBuffer)
 {
     LPCSTR  szString;       // Single byte version.
-    int     iSize;          // Size of resulting string, in wide chars.
+    size_t  cchString;      // Length of the single byte version, including the terminator.
+    size_t  iSize;          // Size of resulting string, in wide chars.
     HRESULT hr = NOERROR;
 
     IfFailGo(getString(ix, &szString));
@@ -116,19 +117,19 @@ CMiniMd::Impl_GetStringW(
             *pcchBuffer = 0;
         goto ErrExit;
     }
-    iSize = ::MultiByteToWideChar(CP_UTF8, 0, szString, -1, szOut, cchBuffer);
+    cchString = strlen(szString) + 1;
+    if (cchBuffer == 0)
+        iSize = minipal_get_length_utf8_to_utf16(szString, cchString, 0);
+    else
+        iSize = szOut != NULL ? minipal_convert_utf8_to_utf16(szString, cchString, (CHAR16_T*)szOut, cchBuffer, 0) : 0;
     if (iSize == 0)
     {
-        // What was the problem?
-        DWORD dwNT = GetLastError();
-
-        // Not truncation?
-        if (dwNT != ERROR_INSUFFICIENT_BUFFER)
-            IfFailGo(HRESULT_FROM_NT(dwNT));
-
         // Truncation error; get the size required.
         if (pcchBuffer != NULL)
-            *pcchBuffer = ::MultiByteToWideChar(CP_UTF8, 0, szString, -1, NULL, 0);
+        {
+            size_t cchNeeded = minipal_get_length_utf8_to_utf16(szString, cchString, 0);
+            *pcchBuffer = (ULONG)cchNeeded;
+        }
 
         if ((szOut != NULL) && (cchBuffer > 0))
         {   // null-terminate the truncated output string
@@ -139,7 +140,7 @@ CMiniMd::Impl_GetStringW(
         goto ErrExit;
     }
     if (pcchBuffer != NULL)
-        *pcchBuffer = iSize;
+        *pcchBuffer = (ULONG)iSize;
 
 ErrExit:
     return hr;
diff --git a/src/coreclr/md/runtime/stgpool.cpp b/src/coreclr/md/runtime/stgpool.cpp
index d0d3524ae6ea88..04395f867cad71 100644
--- a/src/coreclr/md/runtime/stgpool.cpp
+++ b/src/coreclr/md/runtime/stgpool.cpp
@@ -970,7 +970,7 @@ StgStringPool::AddStringW(
     CONTRACTL_END
 
     STRINGHASH  *pHash;                 // Hash item for add.
-    ULONG       iLen;                   // Correct length after conversion.
+    size_t      iLen;                   // Correct length after conversion.
     LPSTR       pData;                  // Pointer to location for new string.
 
     _ASSERTE(!m_bReadOnly);
@@ -986,38 +986,22 @@ StgStringPool::AddStringW(
         return (S_OK);
     }
 
-    // How many bytes will be required in the heap?
-    iLen = ::WideCharToMultiByte(
-        CP_UTF8,
-        0,
-        szString,
-        -1,     // null-terminated string
-        NULL,
-        0,
-        NULL,
-        NULL);
-    // WCTMB includes trailing 0 if (when passing parameter #4 (length) -1.
+    // How many bytes will be required in the heap, including the trailing 0?
+    size_t cchString = u16_strlen(szString) + 1;
+    iLen = minipal_get_length_utf16_to_utf8((const CHAR16_T*)szString, cchString, 0);
 
     // Check for room.
     if (iLen > GetCbSegAvailable())
     {
-        if (!Grow(iLen))
+        if (!Grow((ULONG)iLen))
             return (PostError(OutOfMemory()));
     }
     pData = reinterpret_cast<LPSTR>(GetNextLocation());
 
     // Convert the data in place to the correct location.
-    iLen = ::WideCharToMultiByte(
-        CP_UTF8,
-        0,
-        szString,
-        -1,
-        pData,
-        GetCbSegAvailable(),
-        NULL,
-        NULL);
+    iLen = minipal_convert_utf16_to_utf8((const CHAR16_T*)szString, cchString, pData, GetCbSegAvailable(), 0);
     if (iLen == 0)
-        return (BadError(HRESULT_FROM_NT(GetLastError())));
+        return (BadError(HRESULT_FROM_NT(errno)));
 
     // If the hash table is to be kept built (default).
     if (m_bHash)
@@ -1031,7 +1015,7 @@ StgStringPool::AddStringW(
         if (pHash->iOffset == 0xffffffff)
         {
             *pnOffset = pHash->iOffset = GetNextOffset();
-            SegAllocate(iLen);
+            SegAllocate((ULONG)iLen);
         }
         // Else use the old one.
         else
@@ -1043,7 +1027,7 @@ StgStringPool::AddStringW(
     else
     {
         *pnOffset = GetNextOffset();
-        SegAllocate(iLen);
+        SegAllocate((ULONG)iLen);
     }
     return (S_OK);
 } // StgStringPool::AddStringW
diff --git a/src/coreclr/nativeaot/Runtime/windows/PalCommon.cpp b/src/coreclr/nativeaot/Runtime/windows/PalCommon.cpp
index 8e4e582c5cec00..5d30e1dc218e59 100644
--- a/src/coreclr/nativeaot/Runtime/windows/PalCommon.cpp
+++ b/src/coreclr/nativeaot/Runtime/windows/PalCommon.cpp
@@ -17,6 +17,7 @@
 #include <winternl.h>
 #include "CommonMacros.h"
 #include "rhassert.h"
+#include <minipal/utf8.h>
 
 // Given the OS handle of a loaded module, compute the upper and lower virtual address bounds (inclusive).
 void PalGetModuleBounds(HANDLE hOsHandle, _Out_ uint8_t ** ppLowerBound, _Out_ uint8_t ** ppUpperBound)
@@ -160,15 +161,9 @@ void PalGetPDBInfo(HANDLE hOsHandle, GUID * pGuidSignature, _Out_ uint32_t * pdw
         memcpy(pGuidSignature, &pdbInfoLast.m_pPdb70->signature, sizeof(GUID));
         *pdwAge = pdbInfoLast.m_pPdb70->age;
 
-        // Convert build path from ANSI (UTF-8) to UNICODE (UTF-16)
-        int result = MultiByteToWideChar(
-            CP_UTF8,                // Code page for UTF-8
-            0,                      // No special flags
-            pdbInfoLast.m_pPdb70->path, // Source UTF-8 string
-            -1,                     // Source string length (-1 for null-terminated)
-            wszPath,                // Destination buffer for UTF-16 string
-            cchPath                 // Size of destination buffer
-        );
+        // Convert build path from UTF-8 to UTF-16
+        const char* path = pdbInfoLast.m_pPdb70->path;
+        size_t result = minipal_convert_utf8_to_utf16(path, strlen(path) + 1, (CHAR16_T*)wszPath, cchPath, 0);
 
         if (result == 0)
         {
diff --git a/src/coreclr/nativeaot/Runtime/windows/PalMinWin.cpp b/src/coreclr/nativeaot/Runtime/windows/PalMinWin.cpp
index 529ba14f3f8976..4cbe4991bdffc0 100644
--- a/src/coreclr/nativeaot/Runtime/windows/PalMinWin.cpp
+++ b/src/coreclr/nativeaot/Runtime/windows/PalMinWin.cpp
@@ -5,6 +5,7 @@
 #include <windows.h>
 #include <stdio.h>
 #include <errno.h>
+#include <minipal/utf8.h>
 
 #include "holder.h"
 
@@ -886,7 +887,7 @@ bool PalSetCurrentThreadName(const char* name)
     {
         return false;
     }
-    if (MultiByteToWideChar(CP_UTF8, 0, name, -1, threadNameWide, (int)(len + 1)) == 0)
+    if (minipal_convert_utf8_to_utf16(name, len + 1, (CHAR16_T*)threadNameWide, len + 1, 0) == 0)
     {
         delete[] threadNameWide;
         return false;
@@ -939,15 +940,14 @@ void PalPrintFatalError(const char* message)
 
 char* PalCopyTCharAsChar(const TCHAR* toCopy)
 {
-    int len = ::WideCharToMultiByte(CP_UTF8, 0, toCopy, -1, nullptr, 0, nullptr, nullptr);
-    if (len == 0)
-        return nullptr;
+    size_t length = wcslen(toCopy) + 1;
+    size_t len = minipal_get_length_utf16_to_utf8((const CHAR16_T*)toCopy, length, 0);
 
     char* converted = new (nothrow) char[len];
 
     if (converted != nullptr)
     {
-        int written = ::WideCharToMultiByte(CP_UTF8, 0, toCopy, -1, converted, len, nullptr, nullptr);
+        size_t written = minipal_convert_utf16_to_utf8((const CHAR16_T*)toCopy, length, converted, len, 0);
         assert(len == written);
     }
     return converted;
@@ -962,7 +962,7 @@ HANDLE PalLoadLibrary(const char* moduleName)
     {
         return 0;
     }
-    if (MultiByteToWideChar(CP_UTF8, 0, moduleName, -1, moduleNameWide, (int)(len + 1)) == 0)
+    if (minipal_convert_utf8_to_utf16(moduleName, len + 1, (CHAR16_T*)moduleNameWide, len + 1, 0) == 0)
     {
         return 0;
     }
diff --git a/src/coreclr/nativeresources/resourcestring.cpp b/src/coreclr/nativeresources/resourcestring.cpp
index b3089043cc919a..53c5488c8c8cdf 100644
--- a/src/coreclr/nativeresources/resourcestring.cpp
+++ b/src/coreclr/nativeresources/resourcestring.cpp
@@ -22,7 +22,7 @@ static int CompareNativeStringResources(const void *a, const void *b)
 
 int LoadNativeStringResource(const NativeStringResourceTable &nativeStringResourceTable, unsigned int iResourceID, WCHAR* szBuffer, int iMax, int *pcwchUsed)
 {
-    int len = 0;
+    size_t len = 0;
     if (szBuffer && iMax)
     {
         // Search the sorted set of resources for the ID we're interested in.
@@ -36,16 +36,15 @@ int LoadNativeStringResource(const NativeStringResourceTable &nativeStringResour
 
         if (resourceEntry != NULL)
         {
-            len = MultiByteToWideChar(CP_UTF8, 0, resourceEntry->resourceString, -1, szBuffer, iMax);
+            const char* resourceString = resourceEntry->resourceString;
+            len = minipal_convert_utf8_to_utf16(resourceString, strlen(resourceString) + 1, (CHAR16_T*)szBuffer, iMax, 0);
             if (len == 0)
             {
-                int hr = HRESULT_FROM_GetLastError();
-
                 // Tell the caller if the buffer isn't big enough
-                if (hr == HRESULT_FROM_WIN32(ERROR_INSUFFICIENT_BUFFER) && pcwchUsed)
+                if (pcwchUsed)
                     *pcwchUsed = iMax;
 
-                return hr;
+                return HRESULT_FROM_WIN32(ERROR_INSUFFICIENT_BUFFER);
             }
         }
         else
@@ -64,7 +63,7 @@ int LoadNativeStringResource(const NativeStringResourceTable &nativeStringResour
 
             if (nxt != NULL)
             {
-                len = (int)(nxt - szBuffer);
+                len = (size_t)(nxt - szBuffer);
             }
             else
             {
@@ -79,7 +78,7 @@ int LoadNativeStringResource(const NativeStringResourceTable &nativeStringResour
 
     if (pcwchUsed)
     {
-        *pcwchUsed = len;
+        *pcwchUsed = (int)len;
     }
 
     return S_OK;
diff --git a/src/coreclr/pal/inc/pal.h b/src/coreclr/pal/inc/pal.h
index ff0fdc732d83f7..8e3e3b0b0a4051 100644
--- a/src/coreclr/pal/inc/pal.h
+++ b/src/coreclr/pal/inc/pal.h
@@ -433,11 +433,6 @@ typedef struct _OVERLAPPED {
 #define STD_OUTPUT_HANDLE        ((DWORD)-11)
 #define STD_ERROR_HANDLE         ((DWORD)-12)
 
-PALIMPORT
-UINT
-PALAPI
-GetConsoleOutputCP();
-
 PALIMPORT
 DWORD
 PALAPI
@@ -1994,44 +1989,6 @@ FlushInstructionCache(
               IN LPCVOID lpBaseAddress,
               IN SIZE_T dwSize);
 
-#define MAX_LEADBYTES         12
-#define MAX_DEFAULTCHAR       2
-
-typedef struct _cpinfo {
-    UINT MaxCharSize;
-    BYTE DefaultChar[MAX_DEFAULTCHAR];
-    BYTE LeadByte[MAX_LEADBYTES];
-} CPINFO, *LPCPINFO;
-
-#define MB_PRECOMPOSED            0x00000001
-#define MB_ERR_INVALID_CHARS      0x00000008
-
-PALIMPORT
-int
-PALAPI
-MultiByteToWideChar(
-            IN UINT CodePage,
-            IN DWORD dwFlags,
-            IN LPCSTR lpMultiByteStr,
-            IN int cbMultiByte,
-            OUT LPWSTR lpWideCharStr,
-            IN int cchWideChar);
-
-#define WC_NO_BEST_FIT_CHARS      0x00000400
-
-PALIMPORT
-int
-PALAPI
-WideCharToMultiByte(
-            IN UINT CodePage,
-            IN DWORD dwFlags,
-            IN LPCWSTR lpWideCharStr,
-            IN int cchWideChar,
-            OUT LPSTR lpMultiByteStr,
-            IN int cbMultyByte,
-            IN LPCSTR lpDefaultChar,
-            OUT LPBOOL lpUsedDefaultChar);
-
 #define EXCEPTION_NONCONTINUABLE 0x1
 #define EXCEPTION_UNWINDING 0x2
 
diff --git a/src/coreclr/pal/src/CMakeLists.txt b/src/coreclr/pal/src/CMakeLists.txt
index 9272d2f18bf4b0..543e6802855237 100644
--- a/src/coreclr/pal/src/CMakeLists.txt
+++ b/src/coreclr/pal/src/CMakeLists.txt
@@ -154,7 +154,6 @@ set(SOURCES
   init/pal.cpp
   init/sxs.cpp
   loader/module.cpp
-  locale/unicode.cpp
   misc/cgroup.cpp
   misc/dbgmsg.cpp
   misc/environ.cpp
diff --git a/src/coreclr/pal/src/cruntime/wchar.cpp b/src/coreclr/pal/src/cruntime/wchar.cpp
index aa44b2adc87ef8..7ddcce37ad3e3a 100644
--- a/src/coreclr/pal/src/cruntime/wchar.cpp
+++ b/src/coreclr/pal/src/cruntime/wchar.cpp
@@ -22,6 +22,7 @@ Module Name:
 
 #include <errno.h>
 #include <algorithm>
+#include <minipal/utf8.h>
 
 SET_DEFAULT_DEBUG_CHANNEL(CRT);
 
@@ -36,17 +37,17 @@ __cdecl
 _wtoi(
     const wchar_16 *string)
 {
-    int len;
+    size_t len;
     int ret;
     char *tempStr;
 
     PERF_ENTRY(_wtoi);
     ENTRY("_wtoi (string=%p)\n", string);
 
-    len = WideCharToMultiByte(CP_ACP, 0, string, -1, 0, 0, 0, 0);
+    len = minipal_get_length_utf16_to_utf8((const CHAR16_T*)string, PAL_wcslen(string) + 1, 0);
     if (!len)
     {
-        ASSERT("WideCharToMultiByte failed.  Error is %d\n",
+        ASSERT("UTF-16 to UTF-8 conversion failed.  Error is %d\n",
               GetLastError());
         return -1;
     }
@@ -57,10 +58,10 @@ _wtoi(
         SetLastError(ERROR_NOT_ENOUGH_MEMORY);
         return -1;
     }
-    len = WideCharToMultiByte(CP_ACP, 0, string, -1, tempStr, len, 0, 0);
+    len = minipal_convert_utf16_to_utf8((const CHAR16_T*)string, PAL_wcslen(string) + 1, tempStr, len, 0);
     if (!len)
     {
-        ASSERT("WideCharToMultiByte failed.  Error is %d\n",
+        ASSERT("UTF-16 to UTF-8 conversion failed.  Error is %d\n",
               GetLastError());
         free(tempStr);
         return -1;
@@ -240,18 +241,18 @@ PAL_wcstoul(
     char *s_nptr = 0;
     char *s_endptr = 0;
     unsigned long res;
-    int size;
+    size_t size;
     DWORD dwLastError = 0;
 
     PERF_ENTRY(wcstoul);
     ENTRY("wcstoul (nptr=%p (%S), endptr=%p, base=%d)\n", nptr?nptr:W16_NULLSTRING, nptr?nptr:W16_NULLSTRING,
           endptr, base);
 
-    size = WideCharToMultiByte(CP_ACP, 0, nptr, -1, NULL, 0, NULL, NULL);
+    size = minipal_get_length_utf16_to_utf8((const CHAR16_T*)nptr, PAL_wcslen(nptr) + 1, 0);
     if (!size)
     {
         dwLastError = GetLastError();
-        ASSERT("WideCharToMultiByte failed.  Error is %d\n", dwLastError);
+        ASSERT("UTF-16 to UTF-8 conversion failed.  Error is %d\n", dwLastError);
         SetLastError(ERROR_INVALID_PARAMETER);
         res = 0;
         goto PAL_wcstoulExit;
@@ -264,11 +265,11 @@ PAL_wcstoul(
         res = 0;
         goto PAL_wcstoulExit;
     }
-    size = WideCharToMultiByte(CP_ACP, 0, nptr, -1, s_nptr, size, NULL, NULL);
+    size = minipal_convert_utf16_to_utf8((const CHAR16_T*)nptr, PAL_wcslen(nptr) + 1, s_nptr, size, 0);
     if (!size)
     {
         dwLastError = GetLastError();
-        ASSERT("WideCharToMultiByte failed.  Error is %d\n", dwLastError);
+        ASSERT("UTF-16 to UTF-8 conversion failed.  Error is %d\n", dwLastError);
         SetLastError(ERROR_INVALID_PARAMETER);
         res = 0;
         goto PAL_wcstoulExit;
@@ -330,18 +331,18 @@ PAL__wcstoui64(
     char *s_nptr = 0;
     char *s_endptr = 0;
     unsigned long long res;
-    int size;
+    size_t size;
     DWORD dwLastError = 0;
 
     PERF_ENTRY(wcstoul);
     ENTRY("_wcstoui64 (nptr=%p (%S), endptr=%p, base=%d)\n", nptr?nptr:W16_NULLSTRING, nptr?nptr:W16_NULLSTRING,
           endptr, base);
 
-    size = WideCharToMultiByte(CP_ACP, 0, nptr, -1, NULL, 0, NULL, NULL);
+    size = minipal_get_length_utf16_to_utf8((const CHAR16_T*)nptr, PAL_wcslen(nptr) + 1, 0);
     if (!size)
     {
         dwLastError = GetLastError();
-        ASSERT("WideCharToMultiByte failed.  Error is %d\n", dwLastError);
+        ASSERT("UTF-16 to UTF-8 conversion failed.  Error is %d\n", dwLastError);
         SetLastError(ERROR_INVALID_PARAMETER);
         res = 0;
         goto PAL__wcstoui64Exit;
@@ -354,11 +355,11 @@ PAL__wcstoui64(
         res = 0;
         goto PAL__wcstoui64Exit;
     }
-    size = WideCharToMultiByte(CP_ACP, 0, nptr, -1, s_nptr, size, NULL, NULL);
+    size = minipal_convert_utf16_to_utf8((const CHAR16_T*)nptr, PAL_wcslen(nptr) + 1, s_nptr, size, 0);
     if (!size)
     {
         dwLastError = GetLastError();
-        ASSERT("WideCharToMultiByte failed.  Error is %d\n", dwLastError);
+        ASSERT("UTF-16 to UTF-8 conversion failed.  Error is %d\n", dwLastError);
         SetLastError(ERROR_INVALID_PARAMETER);
         res = 0;
         goto PAL__wcstoui64Exit;
@@ -860,9 +861,8 @@ PAL_wcstod( const wchar_16 * nptr, wchar_16 **endptr )
 
         if ( lpStringRep )
         {
-            if ( WideCharToMultiByte( CP_ACP, 0, lpStartOfExpression, Length,
-                                      lpStringRep, Length + 1 ,
-                                      NULL, 0 ) != 0 )
+            if ( minipal_convert_utf16_to_utf8( (const CHAR16_T*)lpStartOfExpression, Length,
+                                                lpStringRep, Length + 1, 0 ) != 0 )
             {
                 LPSTR ScanStop = NULL;
                 lpStringRep[Length]= 0;
diff --git a/src/coreclr/pal/src/debug/debug.cpp b/src/coreclr/pal/src/debug/debug.cpp
index cdf7e58cc1f03d..0a7097bbccdcf6 100644
--- a/src/coreclr/pal/src/debug/debug.cpp
+++ b/src/coreclr/pal/src/debug/debug.cpp
@@ -24,6 +24,7 @@ SET_DEFAULT_DEBUG_CHANNEL(DEBUG); // some headers have code with asserts, so do
 #include "pal/stackstring.hpp"
 #include "pal/utils.h"
 #include <minipal/ospagesize.h>
+#include <minipal/utf8.h>
 
 #include <signal.h>
 #include <unistd.h>
@@ -170,7 +171,7 @@ OutputDebugStringW(
         IN LPCWSTR lpOutputString)
 {
     CHAR *lpOutputStringA;
-    int strLen;
+    size_t strLen;
 
     PERF_ENTRY(OutputDebugStringW);
     ENTRY("OutputDebugStringW (lpOutputString=%p (%S))\n",
@@ -183,8 +184,7 @@ OutputDebugStringW(
         goto EXIT;
     }
 
-    if ((strLen = WideCharToMultiByte(CP_ACP, 0, lpOutputString, -1, NULL, 0,
-                                      NULL, NULL))
+    if ((strLen = minipal_get_length_utf16_to_utf8((const CHAR16_T*)lpOutputString, PAL_wcslen(lpOutputString) + 1, 0))
         == 0)
     {
         ASSERT("failed to get wide chars length\n");
@@ -200,8 +200,8 @@ OutputDebugStringW(
         goto EXIT;
     }
 
-    if(! WideCharToMultiByte(CP_ACP, 0, lpOutputString, -1,
-                             lpOutputStringA, strLen, NULL, NULL))
+    if(! minipal_convert_utf16_to_utf8((const CHAR16_T*)lpOutputString, PAL_wcslen(lpOutputString) + 1,
+                                       lpOutputStringA, strLen, 0))
     {
         ASSERT("failed to convert wide chars to multibytes\n");
         SetLastError(ERROR_INTERNAL_ERROR);
diff --git a/src/coreclr/pal/src/include/pal/dbgmsg.h b/src/coreclr/pal/src/include/pal/dbgmsg.h
index 4103f2c54c8529..18b43e4152d31a 100644
--- a/src/coreclr/pal/src/include/pal/dbgmsg.h
+++ b/src/coreclr/pal/src/include/pal/dbgmsg.h
@@ -51,7 +51,6 @@ Available channels :
     THREAD  : Threading mechanism
     EXCEPT  : Structured Exception Handling functions
     CRT     : PAL implementation of the C Runtime Library functions
-    UNICODE : Unicode support API
     ARCH    : platform-dependent stuff
     SYNC    : Management of synchronization objects
     FILE    : File I/O API
@@ -166,7 +165,6 @@ typedef enum
     DCI_THREAD,
     DCI_EXCEPT,
     DCI_CRT,
-    DCI_UNICODE,
     DCI_ARCH,
     DCI_SYNC,
     DCI_FILE,
diff --git a/src/coreclr/pal/src/include/pal/utils.h b/src/coreclr/pal/src/include/pal/utils.h
index 2636f04db4cf5f..5a79a099a12d07 100644
--- a/src/coreclr/pal/src/include/pal/utils.h
+++ b/src/coreclr/pal/src/include/pal/utils.h
@@ -90,7 +90,7 @@ Parameters :
 
 Return Value :
     newly allocated buffer containing the converted string. Conversion is
-    performed using CP_ACP. Buffer is allocated with malloc(), release it
+    performed using UTF-8. Buffer is allocated with malloc(), release it
     with free().
     In case if failure, LastError will be set.
 --*/
@@ -109,7 +109,7 @@ Parameters :
 
 Return Value :
     newly allocated buffer containing the converted string. Conversion is
-    performed using CP_ACP. Buffer is allocated with malloc(), release it
+    performed using UTF-8. Buffer is allocated with malloc(), release it
     with free().
     In case if failure, LastError will be set.
 --*/
diff --git a/src/coreclr/pal/src/init/pal.cpp b/src/coreclr/pal/src/init/pal.cpp
index e7ce5834ff974e..0fb193f9da1175 100644
--- a/src/coreclr/pal/src/init/pal.cpp
+++ b/src/coreclr/pal/src/init/pal.cpp
@@ -21,6 +21,7 @@ SET_DEFAULT_DEBUG_CHANNEL(PAL); // some headers have code with asserts, so do th
 #include "../thread/procprivate.hpp"
 #include "pal/module.h"
 #include "pal/environ.h"
+#include <minipal/utf8.h>
 #include "pal/utils.h"
 #include "pal/debug.h"
 #include "pal/init.h"
@@ -691,7 +692,7 @@ BOOL PALInitLock(void)
 static LPWSTR INIT_GetCurrentEXEPath()
 {
     LPWSTR return_value;
-    INT return_size;
+    size_t return_size;
 
     char* path = minipal_getexepath();
     if (!path)
@@ -704,10 +705,10 @@ static LPWSTR INIT_GetCurrentEXEPath()
     real_path.Set(path, strlen(path));
     free(path);
 
-    return_size = MultiByteToWideChar(CP_ACP, 0, real_path, -1, nullptr, 0);
+    return_size = minipal_get_length_utf8_to_utf16(real_path, strlen(real_path) + 1, 0);
     if (0 == return_size)
     {
-        ASSERT("MultiByteToWideChar failure\n");
+        ASSERT("UTF-8 to UTF-16 conversion failure\n");
         return nullptr;
     }
 
@@ -719,10 +720,9 @@ static LPWSTR INIT_GetCurrentEXEPath()
     }
     else
     {
-        if (!MultiByteToWideChar(CP_ACP, 0, real_path, -1,
-                                return_value, return_size))
+        if (!minipal_convert_utf8_to_utf16(real_path, strlen(real_path) + 1, (CHAR16_T*)return_value, return_size, 0))
         {
-            ASSERT("MultiByteToWideChar failure\n");
+            ASSERT("UTF-8 to UTF-16 conversion failure\n");
             free(return_value);
             return_value = nullptr;
         }
diff --git a/src/coreclr/pal/src/loader/module.cpp b/src/coreclr/pal/src/loader/module.cpp
index e1c9501da5021d..d0159ffad21a48 100644
--- a/src/coreclr/pal/src/loader/module.cpp
+++ b/src/coreclr/pal/src/loader/module.cpp
@@ -28,6 +28,7 @@ SET_DEFAULT_DEBUG_CHANNEL(LOADER); // some headers have code with asserts, so do
 #include "pal/init.h"
 #include "pal/environ.h"
 #include "pal/stackstring.hpp"
+#include <minipal/utf8.h>
 
 #include <sys/param.h>
 #include <errno.h>
@@ -381,6 +382,7 @@ GetModuleFileNameA(
     INT name_length;
     DWORD retval = 0;
     LPWSTR wide_name = nullptr;
+    size_t converted = 0;
 
     PERF_ENTRY(GetModuleFileNameA);
     ENTRY("GetModuleFileNameA (hModule=%p, lpFileName=%p, nSize=%u)\n",
@@ -404,9 +406,8 @@ GetModuleFileNameA(
 
     /* Convert module name to Ascii, place it in the supplied buffer */
 
-    name_length = WideCharToMultiByte(CP_ACP, 0, wide_name, -1, lpFileName,
-                                      nSize, nullptr, nullptr);
-    if (name_length == 0)
+    converted = minipal_convert_utf16_to_utf8((const CHAR16_T*)wide_name, PAL_wcslen(wide_name) + 1, lpFileName, nSize, 0);
+    if (converted == 0)
     {
         TRACE("Buffer too small to copy module's file name.\n");
         SetLastError(ERROR_INSUFFICIENT_BUFFER);
@@ -414,6 +415,7 @@ GetModuleFileNameA(
     }
 
     TRACE("File name of module %p is %s\n", hModule, lpFileName);
+    name_length = (INT)converted;
     retval = name_length;
 done:
     UnlockModuleList();
@@ -1293,14 +1295,14 @@ static bool LOADConvertLibraryPathWideStringToMultibyteString(
     _ASSERTE(wideLibraryPath != nullptr);
 
     size_t length = (PAL_wcslen(wideLibraryPath)+1) * MaxWCharToAcpLengthFactor;
-    *multibyteLibraryPathLengthRef = WideCharToMultiByte(CP_ACP, 0, wideLibraryPath, -1, multibyteLibraryPath,
-                                                        length, nullptr, nullptr);
+    size_t converted = minipal_convert_utf16_to_utf8((const CHAR16_T*)wideLibraryPath, PAL_wcslen(wideLibraryPath) + 1, multibyteLibraryPath, length, 0);
+    *multibyteLibraryPathLengthRef = (INT)converted;
 
     if (*multibyteLibraryPathLengthRef == 0)
     {
         DWORD dwLastError = GetLastError();
 
-        ASSERT("WideCharToMultiByte failure! error is %d\n", dwLastError);
+        ASSERT("UTF-16 to UTF-8 conversion failure! error is %d\n", dwLastError);
 
         SetLastError(ERROR_INVALID_PARAMETER);
         return false;
diff --git a/src/coreclr/pal/src/locale/unicode.cpp b/src/coreclr/pal/src/locale/unicode.cpp
deleted file mode 100644
index d163f851676c9d..00000000000000
--- a/src/coreclr/pal/src/locale/unicode.cpp
+++ /dev/null
@@ -1,221 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*++
-Module Name:
-unicode.cpp
-
-Abstract:
-Implementation of all functions related to Unicode support
---*/
-
-#include "pal/thread.hpp"
-
-#include "pal/palinternal.h"
-#include "pal/dbgmsg.h"
-#include <minipal/strings.h>
-#include <minipal/utf8.h>
-#include "pal/cruntime.h"
-#include "pal/stackstring.hpp"
-
-#include <pthread.h>
-#include <locale.h>
-#include <errno.h>
-
-#include <debugmacrosext.h>
-
-using namespace CorUnix;
-
-SET_DEFAULT_DEBUG_CHANNEL(UNICODE);
-
-/*++
-Function:
-GetConsoleOutputCP
-
-See MSDN doc.
---*/
-UINT
-PALAPI
-GetConsoleOutputCP(
-       VOID)
-{
-    return CP_UTF8;
-}
-
-/*++
-Function:
-MultiByteToWideChar
-
-See MSDN doc.
-
---*/
-int
-PALAPI
-MultiByteToWideChar(
-        IN UINT CodePage,
-        IN DWORD dwFlags,
-        IN LPCSTR lpMultiByteStr,
-        IN int cbMultiByte,
-        OUT LPWSTR lpWideCharStr,
-        IN int cchWideChar)
-{
-    INT retval =0;
-
-    PERF_ENTRY(MultiByteToWideChar);
-    ENTRY("MultiByteToWideChar(CodePage=%u, dwFlags=%#x, lpMultiByteStr=%p (%s),"
-    " cbMultiByte=%d, lpWideCharStr=%p, cchWideChar=%d)\n",
-    CodePage, dwFlags, lpMultiByteStr?lpMultiByteStr:"NULL", lpMultiByteStr?lpMultiByteStr:"NULL",
-    cbMultiByte, lpWideCharStr, cchWideChar);
-
-    if (dwFlags & ~(MB_ERR_INVALID_CHARS | MB_PRECOMPOSED))
-    {
-        ASSERT("Error dwFlags(0x%x) parameter is invalid\n", dwFlags);
-        SetLastError(ERROR_INVALID_FLAGS);
-        goto EXIT;
-    }
-
-    if ( (cbMultiByte == 0) || (cchWideChar < 0) ||
-        (lpMultiByteStr == NULL) ||
-        ((cchWideChar != 0) &&
-        ((lpWideCharStr == NULL) ||
-        (lpMultiByteStr == (LPSTR)lpWideCharStr))) )
-    {
-        ERROR("Error lpMultiByteStr parameters are invalid\n");
-        SetLastError(ERROR_INVALID_PARAMETER);
-        goto EXIT;
-    }
-
-    if (CodePage == CP_UTF8 || CodePage == CP_ACP)
-    {
-        if (cbMultiByte < 0)
-            cbMultiByte = strlen(lpMultiByteStr) + 1;
-
-        if (!lpWideCharStr || cchWideChar == 0)
-            retval = minipal_get_length_utf8_to_utf16(lpMultiByteStr, cbMultiByte, dwFlags);
-
-        if (lpWideCharStr)
-        {
-            if (cchWideChar == 0) cchWideChar = retval;
-            retval = minipal_convert_utf8_to_utf16(lpMultiByteStr, cbMultiByte, (CHAR16_T*)lpWideCharStr, cchWideChar, dwFlags);
-        }
-
-        goto EXIT;
-    }
-
-    ERROR( "This code page is not in the system.\n" );
-    SetLastError( ERROR_INVALID_PARAMETER );
-    goto EXIT;
-
-EXIT:
-
-    LOGEXIT("MultiByteToWideChar returns %d.\n",retval);
-    PERF_EXIT(MultiByteToWideChar);
-    return retval;
-}
-
-
-/*++
-Function:
-WideCharToMultiByte
-
-See MSDN doc.
-
---*/
-int
-PALAPI
-WideCharToMultiByte(
-        IN UINT CodePage,
-        IN DWORD dwFlags,
-        IN LPCWSTR lpWideCharStr,
-        IN int cchWideChar,
-        OUT LPSTR lpMultiByteStr,
-        IN int cbMultiByte,
-        IN LPCSTR lpDefaultChar,
-        OUT LPBOOL lpUsedDefaultChar)
-{
-    INT retval =0;
-    char defaultChar = '?';
-    BOOL usedDefaultChar = FALSE;
-
-    PERF_ENTRY(WideCharToMultiByte);
-    ENTRY("WideCharToMultiByte(CodePage=%u, dwFlags=%#x, lpWideCharStr=%p (%S), "
-          "cchWideChar=%d, lpMultiByteStr=%p, cbMultiByte=%d, "
-          "lpDefaultChar=%p, lpUsedDefaultChar=%p)\n",
-          CodePage, dwFlags, lpWideCharStr?lpWideCharStr:W16_NULLSTRING, lpWideCharStr?lpWideCharStr:W16_NULLSTRING,
-          cchWideChar, lpMultiByteStr, cbMultiByte,
-          lpDefaultChar, lpUsedDefaultChar);
-
-    if (dwFlags & ~WC_NO_BEST_FIT_CHARS)
-    {
-        ERROR("dwFlags %d invalid\n", dwFlags);
-        SetLastError(ERROR_INVALID_FLAGS);
-        goto EXIT;
-    }
-
-    // No special action is needed for WC_NO_BEST_FIT_CHARS. The default
-    // behavior of this API on Unix is not to find the best fit for a unicode
-    // character that does not map directly into a code point in the given
-    // code page. The best fit functionality is not available in wctomb on Unix
-    // and is better left unimplemented for security reasons anyway.
-
-    if ((cchWideChar < -1) || (cbMultiByte < 0) ||
-        (lpWideCharStr == NULL) ||
-        ((cbMultiByte != 0) &&
-        ((lpMultiByteStr == NULL) ||
-        (lpWideCharStr == (LPWSTR)lpMultiByteStr))) )
-    {
-        ERROR("Error lpWideCharStr parameters are invalid\n");
-        SetLastError(ERROR_INVALID_PARAMETER);
-        goto EXIT;
-    }
-
-    if (lpDefaultChar != NULL)
-    {
-        defaultChar = *lpDefaultChar;
-    }
-
-    if (CodePage == CP_UTF8 || CodePage == CP_ACP)
-    {
-        if (cchWideChar < 0)
-            cchWideChar = minipal_u16_strlen((CHAR16_T*)lpWideCharStr) + 1;
-
-        if (!lpMultiByteStr || cbMultiByte == 0)
-            retval = minipal_get_length_utf16_to_utf8((CHAR16_T*)lpWideCharStr, cchWideChar, dwFlags);
-
-        if (lpMultiByteStr)
-        {
-            if (cbMultiByte == 0) cbMultiByte = retval;
-            retval = minipal_convert_utf16_to_utf8((CHAR16_T*)lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, dwFlags);
-        }
-
-        goto EXIT;
-    }
-
-    ERROR( "This code page is not in the system.\n" );
-    SetLastError( ERROR_INVALID_PARAMETER );
-    goto EXIT;
-
-EXIT:
-
-    if ( lpUsedDefaultChar != NULL )
-    {
-        *lpUsedDefaultChar = usedDefaultChar;
-    }
-
-    /* Flag the cases when WC_NO_BEST_FIT_CHARS was not specified
-     * but we found characters that had to be replaced with default
-     * characters. Note that Windows would have attempted to find
-     * best fit characters under these conditions and that could pose
-     * a security risk.
-     */
-    _ASSERT_MSG((dwFlags & WC_NO_BEST_FIT_CHARS) || !usedDefaultChar,
-          "WideCharToMultiByte found a string which doesn't round trip: (%p)%S "
-          "and WC_NO_BEST_FIT_CHARS was not specified\n",
-          lpWideCharStr, lpWideCharStr);
-
-    LOGEXIT("WideCharToMultiByte returns INT %d\n", retval);
-    PERF_EXIT(WideCharToMultiByte);
-    return retval;
-}
-
-extern char * g_szCoreCLRPath;
diff --git a/src/coreclr/pal/src/misc/dbgmsg.cpp b/src/coreclr/pal/src/misc/dbgmsg.cpp
index 0b3c0181bc4839..015cb277b42974 100644
--- a/src/coreclr/pal/src/misc/dbgmsg.cpp
+++ b/src/coreclr/pal/src/misc/dbgmsg.cpp
@@ -72,7 +72,6 @@ static const char *dbg_channel_names[]=
     "THREAD",
     "EXCEPT",
     "CRT",
-    "UNICODE",
     "ARCH",
     "SYNC",
     "FILE",
diff --git a/src/coreclr/pal/src/misc/environ.cpp b/src/coreclr/pal/src/misc/environ.cpp
index 919496a124f7bb..a42ccb1c8c0396 100644
--- a/src/coreclr/pal/src/misc/environ.cpp
+++ b/src/coreclr/pal/src/misc/environ.cpp
@@ -12,6 +12,7 @@ Module Name:
 #include "pal/palinternal.h"
 #include "pal/dbgmsg.h"
 #include "pal/environ.h"
+#include <minipal/utf8.h>
 
 #if HAVE_CRT_EXTERNS_H
 #include <crt_externs.h>
@@ -154,7 +155,7 @@ GetEnvironmentVariableW(
 {
     CHAR *inBuff = nullptr;
     CHAR *outBuff = nullptr;
-    INT inBuffSize;
+    size_t inBuffSize;
     DWORD size = 0;
 
     PERF_ENTRY(GetEnvironmentVariableW);
@@ -162,8 +163,7 @@ GetEnvironmentVariableW(
           lpName ? lpName : W16_NULLSTRING,
           lpName ? lpName : W16_NULLSTRING, lpBuffer, nSize);
 
-    inBuffSize = WideCharToMultiByte(CP_ACP, 0, lpName, -1,
-                                     inBuff, 0, nullptr, nullptr);
+    inBuffSize = lpName != nullptr ? minipal_get_length_utf16_to_utf8((const CHAR16_T*)lpName, PAL_wcslen(lpName) + 1, 0) : 0;
     if (0 == inBuffSize)
     {
         ERROR("lpName has to be a valid parameter\n");
@@ -190,10 +190,9 @@ GetEnvironmentVariableW(
         }
     }
 
-    if (0 == WideCharToMultiByte(CP_ACP, 0, lpName, -1, inBuff,
-                                   inBuffSize, nullptr, nullptr))
+    if (0 == minipal_convert_utf16_to_utf8((const CHAR16_T*)lpName, PAL_wcslen(lpName) + 1, inBuff, inBuffSize, 0))
     {
-        ASSERT("WideCharToMultiByte failed!\n");
+        ASSERT("UTF-16 to UTF-8 conversion failed!\n");
         SetLastError(ERROR_INTERNAL_ERROR);
         goto done;
     }
@@ -215,7 +214,8 @@ GetEnvironmentVariableW(
     }
     else
     {
-        size = MultiByteToWideChar(CP_ACP, 0, outBuff, -1, lpBuffer, nSize);
+        size_t converted = minipal_convert_utf8_to_utf16(outBuff, strlen(outBuff) + 1, (CHAR16_T*)lpBuffer, nSize, 0);
+        size = (DWORD)converted;
         if (0 != size)
         {
             // -1 for the null.
@@ -223,7 +223,7 @@ GetEnvironmentVariableW(
         }
         else
         {
-            ASSERT("MultiByteToWideChar failed!\n");
+            ASSERT("UTF-8 to UTF-16 conversion failed!\n");
             SetLastError(ERROR_INTERNAL_ERROR);
             size = 0;
             *lpBuffer = '\0';
@@ -281,8 +281,8 @@ SetEnvironmentVariableW(
 {
     PCHAR name = nullptr;
     PCHAR value = nullptr;
-    INT nameSize = 0;
-    INT valueSize = 0;
+    size_t nameSize = 0;
+    size_t valueSize = 0;
     BOOL bRet = FALSE;
 
     PERF_ENTRY(SetEnvironmentVariableW);
@@ -290,10 +290,9 @@ SetEnvironmentVariableW(
         lpName?lpName:W16_NULLSTRING,
         lpName?lpName:W16_NULLSTRING, lpValue?lpValue:W16_NULLSTRING, lpValue?lpValue:W16_NULLSTRING);
 
-    if ((nameSize = WideCharToMultiByte(CP_ACP, 0, lpName, -1, name, 0,
-                                        nullptr, nullptr)) == 0)
+    if ((nameSize = lpName != nullptr ? minipal_get_length_utf16_to_utf8((const CHAR16_T*)lpName, PAL_wcslen(lpName) + 1, 0) : 0) == 0)
     {
-        ERROR("WideCharToMultiByte failed\n");
+        ERROR("UTF-16 to UTF-8 conversion failed\n");
         SetLastError(ERROR_INVALID_PARAMETER);
         goto done;
     }
@@ -306,20 +305,18 @@ SetEnvironmentVariableW(
         goto done;
     }
 
-    if (0 == WideCharToMultiByte(CP_ACP, 0, lpName,  -1,
-                                 name,  nameSize, nullptr, nullptr))
+    if (0 == minipal_convert_utf16_to_utf8((const CHAR16_T*)lpName, PAL_wcslen(lpName) + 1, name, nameSize, 0))
     {
-        ASSERT("WideCharToMultiByte returned 0\n");
+        ASSERT("UTF-16 to UTF-8 conversion returned 0\n");
         SetLastError(ERROR_INTERNAL_ERROR);
         goto done;
     }
 
     if (lpValue != nullptr)
     {
-        if ((valueSize = WideCharToMultiByte(CP_ACP, 0, lpValue, -1, value,
-                                             0, nullptr, nullptr)) == 0)
+        if ((valueSize = minipal_get_length_utf16_to_utf8((const CHAR16_T*)lpValue, PAL_wcslen(lpValue) + 1, 0)) == 0)
         {
-            ERROR("WideCharToMultiByte failed\n");
+            ERROR("UTF-16 to UTF-8 conversion failed\n");
             SetLastError(ERROR_INVALID_PARAMETER);
             goto done;
         }
@@ -333,10 +330,9 @@ SetEnvironmentVariableW(
             goto done;
         }
 
-        if (0 == WideCharToMultiByte(CP_ACP, 0, lpValue, -1,
-                                     value, valueSize, nullptr, nullptr))
+        if (0 == minipal_convert_utf16_to_utf8((const CHAR16_T*)lpValue, PAL_wcslen(lpValue) + 1, value, valueSize, 0))
         {
-            ASSERT("WideCharToMultiByte failed\n");
+            ASSERT("UTF-16 to UTF-8 conversion failed\n");
             SetLastError( ERROR_INTERNAL_ERROR );
             goto done;
         }
@@ -384,7 +380,8 @@ GetEnvironmentStringsW(
                VOID)
 {
     WCHAR *wenviron = nullptr, *tempEnviron;
-    int i, len, envNum;
+    int i;
+    size_t len, envNum;
 
     PERF_ENTRY(GetEnvironmentStringsW);
     ENTRY("GetEnvironmentStringsW()\n");
@@ -398,7 +395,7 @@ GetEnvironmentStringsW(
     /* get total length of the bytes that we need to allocate */
     for (i = 0; palEnvironment[i] != 0; i++)
     {
-        len = MultiByteToWideChar(CP_ACP, 0, palEnvironment[i], -1, wenviron, 0);
+        len = minipal_get_length_utf8_to_utf16(palEnvironment[i], strlen(palEnvironment[i]) + 1, 0);
         envNum += len;
     }
 
@@ -414,7 +411,7 @@ GetEnvironmentStringsW(
     tempEnviron = wenviron;
     for (i = 0; palEnvironment[i] != 0; i++)
     {
-        len = MultiByteToWideChar(CP_ACP, 0, palEnvironment[i], -1, tempEnviron, envNum);
+        len = minipal_convert_utf8_to_utf16(palEnvironment[i], strlen(palEnvironment[i]) + 1, (CHAR16_T*)tempEnviron, envNum, 0);
         tempEnviron += len;
         envNum      -= len;
     }
diff --git a/src/coreclr/pal/src/misc/fmtmessage.cpp b/src/coreclr/pal/src/misc/fmtmessage.cpp
index f096156f23847e..c578639080aa7e 100644
--- a/src/coreclr/pal/src/misc/fmtmessage.cpp
+++ b/src/coreclr/pal/src/misc/fmtmessage.cpp
@@ -22,6 +22,7 @@ Revision History:
 #include "pal/palinternal.h"
 #include "pal/dbgmsg.h"
 #include "pal/module.h"
+#include <minipal/utf8.h>
 
 #include "errorstrings.h"
 
@@ -104,12 +105,9 @@ static INT FMTMSG__watoi( LPWSTR str )
 {
     CONST UINT MAX_NUMBER_LENGTH = 3;
     CHAR buf[ MAX_NUMBER_LENGTH ];
-    INT nRetVal = 0;
+    size_t converted = minipal_convert_utf16_to_utf8((const CHAR16_T*)str, PAL_wcslen(str) + 1, buf, MAX_NUMBER_LENGTH, 0);
 
-    nRetVal = WideCharToMultiByte( CP_ACP, 0, str, -1, buf,
-                                   MAX_NUMBER_LENGTH, NULL, 0 );
-
-    if ( nRetVal != 0 )
+    if ( converted != 0 )
     {
         return atoi( buf );
     }
diff --git a/src/coreclr/pal/src/misc/utils.cpp b/src/coreclr/pal/src/misc/utils.cpp
index c9f5ba80a78d9b..5bd995307518e8 100644
--- a/src/coreclr/pal/src/misc/utils.cpp
+++ b/src/coreclr/pal/src/misc/utils.cpp
@@ -26,6 +26,7 @@ SET_DEFAULT_DEBUG_CHANNEL(MISC); // some headers have code with asserts, so do t
 
 #include <errno.h>
 #include <string.h>
+#include <minipal/utf8.h>
 
 
 // In safemath.h, Template SafeInt uses macro _ASSERTE, which need to use variable
@@ -46,18 +47,18 @@ Parameters :
 
 Return Value :
     newly allocated buffer containing the converted string. Conversion is
-    performed using CP_ACP. Buffer is allocated with malloc(), release it
+    performed using UTF-8. Buffer is allocated with malloc(), release it
     with free().
     In case if failure, LastError will be set.
 --*/
 LPSTR UTIL_WCToMB_Alloc(LPCWSTR lpWideCharStr, int cchWideChar)
 {
-    int length;
+    size_t cchSource = cchWideChar < 0 ? PAL_wcslen(lpWideCharStr) + 1 : (size_t)cchWideChar;
+    size_t length;
     LPSTR lpMultiByteStr;
 
     /* get required buffer length */
-    length = WideCharToMultiByte(CP_ACP, 0, lpWideCharStr, cchWideChar,
-                                 NULL, 0, NULL, NULL);
+    length = minipal_get_length_utf16_to_utf8((const CHAR16_T*)lpWideCharStr, cchSource, 0);
     if(0 == length)
     {
         ERROR("WCToMB error; GetLastError returns %#x", GetLastError());
@@ -74,8 +75,7 @@ LPSTR UTIL_WCToMB_Alloc(LPCWSTR lpWideCharStr, int cchWideChar)
     }
 
     /* convert into allocated buffer */
-    length = WideCharToMultiByte(CP_ACP, 0, lpWideCharStr, cchWideChar,
-                                 lpMultiByteStr, length, NULL, NULL);
+    length = minipal_convert_utf16_to_utf8((const CHAR16_T*)lpWideCharStr, cchSource, lpMultiByteStr, length, 0);
     if(0 == length)
     {
         ASSERT("WCToMB error; GetLastError returns %#x\n", GetLastError());
@@ -98,18 +98,18 @@ Parameters :
 
 Return Value :
     newly allocated buffer containing the converted string. Conversion is
-    performed using CP_ACP. Buffer is allocated with malloc(), release it
+    performed using UTF-8. Buffer is allocated with malloc(), release it
     with free().
     In case if failure, LastError will be set.
 --*/
 LPWSTR UTIL_MBToWC_Alloc(LPCSTR lpMultiByteStr, int cbMultiByte)
 {
-    int length;
+    size_t cbSource = cbMultiByte < 0 ? strlen(lpMultiByteStr) + 1 : (size_t)cbMultiByte;
+    size_t length;
     LPWSTR lpWideCharStr;
 
     /* get required buffer length */
-    length = MultiByteToWideChar(CP_ACP, 0, lpMultiByteStr, cbMultiByte,
-                                      NULL, 0);
+    length = minipal_get_length_utf8_to_utf16(lpMultiByteStr, cbSource, 0);
     if(0 == length)
     {
         ERROR("MBToWC error; GetLastError returns %#x", GetLastError());
@@ -120,7 +120,7 @@ LPWSTR UTIL_MBToWC_Alloc(LPCSTR lpMultiByteStr, int cbMultiByte)
     size_t fullsize;
     if (!ClrSafeInt<size_t>::multiply(length,sizeof(WCHAR),fullsize))
     {
-        ERROR("integer overflow! length = %d , sizeof(WCHAR) = (%d)\n", length,sizeof(WCHAR) );
+        ERROR("integer overflow! length = %zu , sizeof(WCHAR) = (%zu)\n", length,sizeof(WCHAR) );
         SetLastError(ERROR_ARITHMETIC_OVERFLOW);
         return NULL;
     }
@@ -134,9 +134,8 @@ LPWSTR UTIL_MBToWC_Alloc(LPCSTR lpMultiByteStr, int cbMultiByte)
     }
 
     /* convert into allocated buffer */
-    length = MultiByteToWideChar(CP_ACP, 0, lpMultiByteStr, cbMultiByte,
-                                      lpWideCharStr, length);
-    if(0 >= length)
+    length = minipal_convert_utf8_to_utf16(lpMultiByteStr, cbSource, (CHAR16_T*)lpWideCharStr, length, 0);
+    if(0 == length)
     {
         ASSERT("MCToMB error; GetLastError returns %#x\n", GetLastError());
         free(lpWideCharStr);
diff --git a/src/coreclr/pal/src/thread/thread.cpp b/src/coreclr/pal/src/thread/thread.cpp
index cb21db893f0f49..f5d80cbf0063c4 100644
--- a/src/coreclr/pal/src/thread/thread.cpp
+++ b/src/coreclr/pal/src/thread/thread.cpp
@@ -24,6 +24,7 @@ SET_DEFAULT_DEBUG_CHANNEL(THREAD); // some headers have code with asserts, so do
 #include "pal/module.h"
 #include "pal/environ.h"
 #include "pal/init.h"
+#include <minipal/utf8.h>
 #include "pal/utils.h"
 
 #include <minipal/thread.h>
@@ -1302,7 +1303,7 @@ SetThreadDescription(
 
     CPalThread *pTargetThread = NULL;
     IPalObject *pobjThread = NULL;
-    int nameSize;
+    size_t nameSize;
     char *nameBuf = NULL;
 
     PAL_ERROR palError = InternalGetThreadDataFromHandle(pThread, hThread, &pTargetThread, &pobjThread);
@@ -1312,11 +1313,11 @@ SetThreadDescription(
         // it causes the value returned by Process.ProcessName to change.
         if ((pid_t)pTargetThread->GetThreadId() != getpid())
         {
-            nameSize = WideCharToMultiByte(CP_ACP, 0, lpThreadDescription, -1, NULL, 0, NULL, NULL);
+            nameSize = lpThreadDescription != NULL ? minipal_get_length_utf16_to_utf8((const CHAR16_T*)lpThreadDescription, PAL_wcslen(lpThreadDescription) + 1, 0) : 0;
             if (nameSize > 0)
             {
                 nameBuf = (char *)malloc(nameSize);
-                if (nameBuf == NULL || WideCharToMultiByte(CP_ACP, 0, lpThreadDescription, -1, nameBuf, nameSize, NULL, NULL) != nameSize)
+                if (nameBuf == NULL || minipal_convert_utf16_to_utf8((const CHAR16_T*)lpThreadDescription, PAL_wcslen(lpThreadDescription) + 1, nameBuf, nameSize, 0) != nameSize)
                 {
                     pThread->SetLastError(ERROR_INSUFFICIENT_BUFFER);
                 }
diff --git a/src/coreclr/pal/tests/palsuite/CMakeLists.txt b/src/coreclr/pal/tests/palsuite/CMakeLists.txt
index e1362b3e39a900..f4c57af54c0ca7 100644
--- a/src/coreclr/pal/tests/palsuite/CMakeLists.txt
+++ b/src/coreclr/pal/tests/palsuite/CMakeLists.txt
@@ -38,24 +38,6 @@ add_executable_clr(paltests
   EXCLUDE_FROM_ALL
   paltests.cpp
   common/palsuite.cpp
-  c_runtime/atof/test1/test1.cpp
-  c_runtime/atoi/test1/test1.cpp
-  c_runtime/isalnum/test1/test1.cpp
-  c_runtime/isalpha/test1/test1.cpp
-  c_runtime/isdigit/test1/test1.cpp
-  c_runtime/isprint/test1/isprint.cpp
-  c_runtime/isprint/test2/test2.cpp
-  c_runtime/isspace/test1/test1.cpp
-  c_runtime/iswdigit/test1/test1.cpp
-  #c_runtime/iswprint/test1/test1.cpp
-  c_runtime/iswspace/test1/test1.cpp
-  c_runtime/iswupper/test1/test1.cpp
-  c_runtime/isxdigit/test1/test1.cpp
-  c_runtime/llabs/test1/test1.cpp
-  c_runtime/memchr/test1/test1.cpp
-  c_runtime/memcmp/test1/test1.cpp
-  c_runtime/memmove/test1/test1.cpp
-  c_runtime/memset/test1/test1.cpp
   c_runtime/sscanf_s/test1/test1.cpp
   c_runtime/sscanf_s/test10/test10.cpp
   c_runtime/sscanf_s/test11/test11.cpp
@@ -73,21 +55,6 @@ add_executable_clr(paltests
   c_runtime/sscanf_s/test7/test7.cpp
   c_runtime/sscanf_s/test8/test8.cpp
   c_runtime/sscanf_s/test9/test9.cpp
-  c_runtime/strcat/test1/test1.cpp
-  c_runtime/strchr/test1/test1.cpp
-  c_runtime/strcmp/test1/test1.cpp
-  c_runtime/strcpy/test1/test1.cpp
-  c_runtime/strlen/test1/test1.cpp
-  c_runtime/strncat/test1/test1.cpp
-  c_runtime/strncmp/test1/test1.cpp
-  c_runtime/strncpy/test1/test1.cpp
-  c_runtime/strpbrk/test1/test1.cpp
-  c_runtime/strrchr/test1/test1.cpp
-  c_runtime/strstr/test1/test1.cpp
-  c_runtime/tolower/test1/test1.cpp
-  c_runtime/toupper/test1/test1.cpp
-  c_runtime/towlower/test1/test1.cpp
-  c_runtime/towupper/test1/test1.cpp
   c_runtime/wcscat/test1/test1.cpp
   c_runtime/wcschr/test1/test1.cpp
   c_runtime/wcscmp/test1/test1.cpp
@@ -105,9 +72,6 @@ add_executable_clr(paltests
   c_runtime/wcstoul/test4/test4.cpp
   c_runtime/wcstoul/test5/test5.cpp
   c_runtime/wcstoul/test6/test6.cpp
-  c_runtime/_alloca/test1/test1.cpp
-  c_runtime/_rotl/test1/test1.cpp
-  c_runtime/_rotr/test1/test1.cpp
   c_runtime/_vsnprintf_s/test1/test1.cpp
   c_runtime/_vsnprintf_s/test10/test10.cpp
   c_runtime/_vsnprintf_s/test11/test11.cpp
@@ -166,32 +130,10 @@ add_executable_clr(paltests
 #  filemapping_memmgt/GetProcAddress/test2/testlib.cpp
   filemapping_memmgt/ProbeMemory/ProbeMemory_neg1/ProbeMemory_neg.cpp
   filemapping_memmgt/ProbeMemory/test1/ProbeMemory.cpp
-  loader/LoadLibraryA/test1/LoadLibraryA.cpp
-  loader/LoadLibraryA/test2/LoadLibraryA.cpp
-  loader/LoadLibraryA/test3/loadlibrarya.cpp
-  loader/LoadLibraryA/test5/loadlibrarya.cpp
-  #loader/LoadLibraryA/test6/dlltest.cpp
-  #loader/LoadLibraryA/test6/loadlibrarya.cpp
-  loader/LoadLibraryA/test7/LoadLibraryA.cpp
-  #loader/LoadLibraryA/test8/dlltest.cpp
-  #loader/LoadLibraryA/test8/loadlibrarya.cpp
   loader/LoadLibraryW/test1/LoadLibraryW.cpp
   loader/LoadLibraryW/test2/loadlibraryw.cpp
   loader/LoadLibraryW/test3/loadlibraryw.cpp
   loader/LoadLibraryW/test5/loadlibraryw.cpp
-  #locale_info/CompareStringA/test1/test1.cpp
-  #locale_info/CompareStringW/test1/test1.cpp
-  #locale_info/GetLocaleInfoW/test1/test1.cpp
-  #locale_info/GetLocaleInfoW/test2/test2.cpp
-  locale_info/MultiByteToWideChar/test1/test1.cpp
-  locale_info/MultiByteToWideChar/test2/test2.cpp
-  locale_info/MultiByteToWideChar/test3/test3.cpp
-  locale_info/MultiByteToWideChar/test4/test4.cpp
-  locale_info/WideCharToMultiByte/test1/test1.cpp
-  locale_info/WideCharToMultiByte/test2/test2.cpp
-  locale_info/WideCharToMultiByte/test3/test3.cpp
-  locale_info/WideCharToMultiByte/test4/test4.cpp
-  locale_info/WideCharToMultiByte/test5/test5.cpp
   miscellaneous/CloseHandle/test2/test.cpp
   miscellaneous/FlushInstructionCache/test1/test1.cpp
   miscellaneous/FormatMessageW/test1/test.cpp
@@ -234,11 +176,6 @@ add_executable_clr(paltests
   miscellaneous/InterlockedIncrement/test2/test.cpp
   miscellaneous/InterlockedIncrement64/test1/test.cpp
   miscellaneous/InterlockedIncrement64/test2/test.cpp
-  #miscellaneous/IsBadCodePtr/test1/test1.cpp
-  #miscellaneous/IsBadReadPtr/test1/test.cpp
-  #miscellaneous/IsBadWritePtr/test1/test.cpp
-  #miscellaneous/IsBadWritePtr/test2/test2.cpp
-  #miscellaneous/IsBadWritePtr/test3/test3.cpp
   miscellaneous/SetEnvironmentVariableA/test1/test1.cpp
   miscellaneous/SetEnvironmentVariableA/test2/test2.cpp
   miscellaneous/SetEnvironmentVariableA/test3/test3.cpp
@@ -250,8 +187,6 @@ add_executable_clr(paltests
   miscellaneous/SetLastError/test1/test.cpp
   pal_specific/PAL_Initialize_Terminate/test1/PAL_Initialize_Terminate.cpp
   pal_specific/PAL_Initialize_Terminate/test2/pal_initialize_twice.cpp
-#  pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test1/PAL_RegisterLibraryW_UnregisterLibraryW.cpp
-#  pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test2_neg/reg_unreg_libraryw_neg.cpp
   samples/test1/test.cpp
   samples/test2/test.cpp
   threading/CreateThread/test1/test1.cpp
@@ -272,8 +207,6 @@ add_executable_clr(paltests
   threading/QueryThreadCycleTime/test1/test1.cpp
   threading/ResumeThread/test1/test1.cpp
   threading/RuntimeEvent/test1/test1.cpp
-  threading/Sleep/test1/Sleep.cpp
-  threading/Sleep/test2/sleep.cpp
   threading/SwitchToThread/test1/test1.cpp
   threading/TerminateProcess/test1/TerminateProcess.cpp
   threading/ThreadPriority/test1/ThreadPriority.cpp
diff --git a/src/coreclr/pal/tests/palsuite/DisabledTests.txt b/src/coreclr/pal/tests/palsuite/DisabledTests.txt
index 6b665948ce27e1..e5d3f730249cef 100644
--- a/src/coreclr/pal/tests/palsuite/DisabledTests.txt
+++ b/src/coreclr/pal/tests/palsuite/DisabledTests.txt
@@ -15,13 +15,11 @@ The above testcases were disabled in the palsuite, because they depend heavily o
 WaitForDebugEvent,DebugActiveProcess and ContinueDebugEvent, where these api's
 have been removed from the PAL.
 
-locale_info/getcpinfo/test2:
 =======================================
 This test will be useful in future versions for testing various
 languages (code pages).  Currently only U.S. English (tested by -
 test1) is supported.
 
-locale_info/getcpinfo/test3:
 =======================================
 This test will be useful in future versions for testing various
 languages (code pages).  Currently only U.S. English (tested by -
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/_alloca/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/_alloca/test1/test1.cpp
deleted file mode 100644
index d11b65e99dce05..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/_alloca/test1/test1.cpp
+++ /dev/null
@@ -1,61 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Checks that _alloca allocates memory, and that the memory is
-**          readable and writeable.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(c_runtime__alloca_test1_paltest_alloca_test1, "c_runtime/_alloca/test1/paltest_alloca_test1")
-{
-
-    char *testA = NULL;
-    int i = 0;
-
-    /*
-     * Initialize the PAL and return FAIL if this fails
-     */
-    if (0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-
-
-    /* check that _alloca really gives us addressable memory */
-    testA = (char *)_alloca(20 * sizeof(char));
-    if (testA == NULL)
-    {
-        Fail ("The call to _alloca failed\n");
-    }
-
-    memset(testA, 'a', 20);
-
-    for (i = 0; i < 20; i++)
-    {
-        if (testA[i] != 'a')
-        {
-            Fail ("The memory returned by _alloca doesn't seem to be"
-                    " properly allocated\n");
-        }
-    }
-    
-    PAL_Terminate();
-    return PASS;
-}
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/_rotl/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/_rotl/test1/test1.cpp
deleted file mode 100644
index 52f321ec97064f..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/_rotl/test1/test1.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c (_rotl)
-**
-** Purpose: Tests the PAL implementation of the _rotl function. 
-**          The _rotl function rotates the unsigned value. _rotl
-**          rotates the value left and "wraps" bits rotated off 
-**          one end of value to the other end.  
-**          This test compares the result to a previously determined
-**          value.
-**          
-**
-**
-**===================================================================*/
-#include <palsuite.h>
-
-PALTEST(c_runtime__rotl_test1_paltest_rotl_test1, "c_runtime/_rotl/test1/paltest_rotl_test1")
-{
-    unsigned results = 0;
-    int i,j;
-   
-    unsigned hTestNums[5][8] = {
-        {0x00ff, 0x01fe, 0x03fc, 0x07f8, 0x0ff0, 0x1fe0, 0x3fc0, 0x7f80},
-        {0x0055, 0x00aa, 0x0154, 0x02a8, 0x0550, 0x0aa0, 0x1540, 0x2a80},
-        {0x0099, 0x0132, 0x0264, 0x04c8, 0x0990, 0x1320, 0x2640, 0x4c80},
-        {0x0036, 0x006c, 0x00d8, 0x01b0, 0x0360, 0x06c0, 0x0d80, 0x1b00},
-        {0x008f, 0x011e, 0x023c, 0x0478, 0x08f0, 0x11e0, 0x23c0, 0x4780}};
-  
-    if ((PAL_Initialize(argc, argv)) != 0)
-    {
-        return (FAIL);
-    }
-
-    /*Loop through expected test results*/
-    for (j = 0; j <= 4; j++)
-    {
-        for(i = 1; i <= 7; i++)
-        {
-            results = _rotl(hTestNums[j][0], i);
-            if (results != hTestNums[j][i])
-            {
-                Fail("ERROR: \"0x%4.4x\" rotated bits to the left %d times"
-                    " gave \"0x%4.4x\", expected \"0x%4.4x\"\n", 
-                    hTestNums[j][0], i, results, hTestNums[j][i]) ;
-            }
-        }
-    }
-
-    PAL_Terminate();
-    return (PASS);
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/_rotr/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/_rotr/test1/test1.cpp
deleted file mode 100644
index 2f753c56b6c174..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/_rotr/test1/test1.cpp
+++ /dev/null
@@ -1,59 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c (_rotr)
-**
-** Purpose: Tests the PAL implementation of the _rotr function. 
-**          The _rotr function rotates the unsigned value. _rotr
-**          rotates the value right and "wraps" bits rotated off 
-**          one end of value to the other end.  
-**          This test compares the result to a previously 
-**          determined value.
-**
-**
-**===================================================================*/
-#include <palsuite.h>
-
-PALTEST(c_runtime__rotr_test1_paltest_rotr_test1, "c_runtime/_rotr/test1/paltest_rotr_test1")
-{
-    unsigned results = 0;
-    int i,j;
-   
-    unsigned hTestNums[5][8] = {
-        {0x00ff, 0x8000007f, 0xc000003f, 0xe000001f, 
-            0xf000000f, 0xf8000007, 0xfc000003, 0xfe000001},
-        {0x0055, 0x8000002a, 0x40000015, 0xa000000a, 
-            0x50000005, 0xa8000002, 0x54000001, 0xaa000000},
-        {0x0099, 0x8000004c, 0x40000026, 0x20000013,
-            0x90000009, 0xc8000004, 0x64000002, 0x32000001},
-        {0x0036, 0x001b, 0x8000000d, 0xc0000006, 
-            0x60000003, 0xb0000001, 0xd8000000, 0x6c000000},
-        {0x008f, 0x80000047, 0xc0000023, 0xe0000011,
-            0xf0000008, 0x78000004, 0x3c000002 ,0x1e000001}};
-  
-    
-    if ((PAL_Initialize(argc, argv)) != 0)
-    {
-        return (FAIL);
-    }
-
-    /*Loop through expected test results*/
-    for (j = 0; j <= 4; j++)
-    {
-        for(i = 1; i <= 7; i++)
-        {
-            results = _rotr(hTestNums[j][0], i);
-            if (results != hTestNums[j][i])
-            {
-                Fail("ERROR: \"0x%4.4x\" rotated bits to the left %d times"
-                    " gave \"0x%4.4x\", expected \"0x%4.4x\"\n", 
-                    hTestNums[j][0], i, results, hTestNums[j][i]) ;
-            }
-        }
-    }
-
-    PAL_Terminate();
-    return (PASS);
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/atof/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/atof/test1/test1.cpp
deleted file mode 100644
index 6d8becb3d955b2..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/atof/test1/test1.cpp
+++ /dev/null
@@ -1,74 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Passes to atof() a series of strings containing floats,
-**          checking that each one is correctly extracted.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-#include <float.h>
-
-struct testCase
-{
-    float fvalue;
-    char avalue[20];
-};
-
-PALTEST(c_runtime_atof_test1_paltest_atof_test1, "c_runtime/atof/test1/paltest_atof_test1")
-{
-    int i = 0;
-    double f = 0;
-    struct testCase testCases[] =
-    {
-        {1234, "1234"},
-        {-1234, "-1234"},
-        {1234e-5, "1234e-5"},
-        {1234e+5, "1234e+5"},
-        {1234e5, "1234E5"},
-        {1234.567e-8, "1234.567e-8"},
-        {1234.567e-8, "   1234.567e-8 foo"},
-        {0,"a12"}
-    };
-
-    /*
-     *  Initialize the PAL and return FAIL if this fails
-     */
-    if (0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-        /*Convert the string to a float.*/
-        f = atof(testCases[i].avalue);
-        double result = f - testCases[i].fvalue;
-
-        if (fabs(result) > FLT_EPSILON)
-        {
-            Fail ("atof misinterpreted \"%s\" as %g instead of %g. result %g fabs %g\n",
-                testCases[i].avalue, f, testCases[i].fvalue, result, fabs(result));
-        }
-    }
-    PAL_Terminate();
-    return PASS;
-}
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/atoi/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/atoi/test1/test1.cpp
deleted file mode 100644
index 3137bf903e6824..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/atoi/test1/test1.cpp
+++ /dev/null
@@ -1,85 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests the PAL implementation of the atoi function.
-**          Check to ensure that the different ints (normal,
-**          negative, decimal,exponent), all work as expected with
-**          this function.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-
-struct testCase
-{
-    int IntValue;
-    char avalue[20];
-};
-
-PALTEST(c_runtime_atoi_test1_paltest_atoi_test1, "c_runtime/atoi/test1/paltest_atoi_test1")
-{
-
-    int result=0;
-    int i=0;
-
-    struct testCase testCases[] =
-        {
-            {1234,  "1234"},
-            {-1234, "-1234"},
-            {1234,  "1234.44"},
-            {1234,  "1234e-5"},
-            {1234,  "1234e+5"},
-            {1234,  "1234E5"},
-            {1234,  "1234.657e-8"},
-            {1234567,  "   1234567e-8 foo"},
-            {0,     "aaa 32 test"}
-        };
-
-    /*
-     *  Initialize the PAL and return FAIL if this fails
-     */
-    if (0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-
-    /* Loop through each case.  Convert the string to an int
-       and then compare to ensure that it is the correct value.
-    */
-
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-        /*Convert the string to an int.*/
-        result = atoi(testCases[i].avalue);
-
-        if (testCases[i].IntValue != result)
-        {
-            Fail("ERROR: atoi misinterpreted \"%s\" as %i instead of %i.\n"
-                   , testCases[i].avalue, result, testCases[i].IntValue);
-        }
-
-    }
-
-
-    PAL_Terminate();
-    return PASS;
-}
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/isalnum/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/isalnum/test1/test1.cpp
deleted file mode 100644
index b7ec330ae94769..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/isalnum/test1/test1.cpp
+++ /dev/null
@@ -1,87 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests the PAL implementation of the isalnum function
-**          Check that a number of characters return the correct
-**          values for whether they are alpha/numeric or not.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-
-struct testCase
-{
-    int CorrectResult;
-    int character;
-};
-
-PALTEST(c_runtime_isalnum_test1_paltest_isalnum_test1, "c_runtime/isalnum/test1/paltest_isalnum_test1")
-{
-  
-    int result;  
-    int i;
-  
-    struct testCase testCases[] = 
-        {
-            {1,  'a'},  
-            {1, 'z'},
-            {1,  'B'},
-            {1,  '5'},
-            {1,  '0'},
-            {0,  '?'},  
-            {0,  230}
-        };
-  
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-  
-    /* Loop through each case. Check to see if each is alpha/numeric or
-       not.
-    */
-  
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-      
-        result = isalnum(testCases[i].character);
-     
-        /* The return value is 'non-zero' for success.  This if condition
-         * will still work if that non-zero isn't just 1 
-         */ 
-        if ( ((testCases[i].CorrectResult == 1) && (result == 0)) ||
-             ( (testCases[i].CorrectResult == 0) && (result != 0) ))
-        {
-            Fail("ERROR: isalnum returned %i instead of %i for character "
-                   " %c.\n",
-                   result,
-                   testCases[i].CorrectResult, 
-                   testCases[i].character);
-        }
-    
-    }      
-  
-  
-    PAL_Terminate();
-    return PASS;
-} 
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/isalpha/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/isalpha/test1/test1.cpp
deleted file mode 100644
index 581f5d3e277ad8..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/isalpha/test1/test1.cpp
+++ /dev/null
@@ -1,85 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests the PAL implementation of the isalpha function
-**          Check that a number of characters return the correct
-**          values for whether they are alpha or not.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    int CorrectResult;
-    int character;
-};
-
-PALTEST(c_runtime_isalpha_test1_paltest_isalpha_test1, "c_runtime/isalpha/test1/paltest_isalpha_test1")
-{
-  
-    int result;  
-    int i;
-  
-    struct testCase testCases[] = 
-        {
-            {1,  'a'},  
-            {1, 'z'},
-            {1,  'B'},
-            {0,  '5'},
-            {0,  '?'},  
-            {0,  230}
-        };
-  
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-  
-    /* Loop through each case. Check to see if each is alpha or
-       not.
-    */
-  
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-      
-        result = isalpha(testCases[i].character);
-     
-        /* The return value is 'non-zero' for success.  This if condition
-         * will still work if that non-zero isn't just 1 
-         */ 
-        if ( ((testCases[i].CorrectResult == 1) && (result == 0)) ||
-             ( (testCases[i].CorrectResult == 0) && (result != 0) ))
-        {
-            Fail("ERROR: isalpha returned %i instead of %i for character "
-                   "%c.\n",
-                   result,
-                   testCases[i].CorrectResult, 
-                   testCases[i].character);
-        }
-    
-    }      
-  
-  
-    PAL_Terminate();
-    return PASS;
-} 
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/isdigit/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/isdigit/test1/test1.cpp
deleted file mode 100644
index d84029f9322d14..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/isdigit/test1/test1.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Checks every character against the known range of digits.
-**
-**
-**==========================================================================*/
-
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_isdigit_test1_paltest_isdigit_test1, "c_runtime/isdigit/test1/paltest_isdigit_test1")
-{
-    int i;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    for (i=0; i<256; i++)
-    {
-        if (isdigit(i))
-        {
-            if (i < '0' || i > '9')
-            {
-                Fail("ERROR: isdigit returned true for '%c' (%d)!\n", i, i);
-            }
-        }
-        else
-        {
-            if (i >= '0' && i <= '9')
-            {
-                Fail("ERROR: isdigit returned false for '%c' (%d)!\n", i, i);
-            }
-        }
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/isprint/test1/isprint.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/isprint/test1/isprint.cpp
deleted file mode 100644
index 0d3f0618024c6b..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/isprint/test1/isprint.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source: isprint.c
-**
-** Purpose: Positive test the isprint API.
-**          Call isprint to test if a character is printable 
-**
-**
-**============================================================*/
-#include <palsuite.h>
-
-PALTEST(c_runtime_isprint_test1_paltest_isprint_test1, "c_runtime/isprint/test1/paltest_isprint_test1")
-{
-    int err;
-    int index;
-
-    /*Initialize the PAL environment*/
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        return FAIL;
-    }
-
-    /*check if the character is printable*/
-    for(index = 0x20; index<=0x7E;index++)
-    {
-        err = isprint(index);
-        if(0 == err)
-        {
-            Fail("\nFailed to call isprint API to check "
-                "printable character from 0x20 to 0x7E!\n");
-        }
-    }
-
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/isprint/test2/test2.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/isprint/test2/test2.cpp
deleted file mode 100644
index 9871c1d221a66b..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/isprint/test2/test2.cpp
+++ /dev/null
@@ -1,58 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source: isprint.c
-**
-** Purpose: Negative test for the isprint API. Call isprint 
-**			to test if out of range characters are 
-**			not printable.
-**
-**
-**============================================================*/
-#include <palsuite.h>
-
-PALTEST(c_runtime_isprint_test2_paltest_isprint_test2, "c_runtime/isprint/test2/paltest_isprint_test2")
-{
-    int err;
-
-    /*Initialize the PAL environment*/
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        return FAIL;
-    }
-
-    /*check that function fails for values that are not printable*/
-    err = isprint(0x15);
-    if(err)
-    {
-        Fail("\nSucceeded when it should have failed because 0x15 "
-        "is not in the range of printable characters\n");
-    }
-
-    err = isprint(0xAA);
-    if(err)
-    {
-        Fail("\nSucceeded when it should have failed because 0xAA "
-        "is not in the range of printable characters\n");
-    }
-    
-    /* check carriage return */
-    if(0 != isprint(0x0d))
-    {
-        Fail("\nSucceeded when it should have failed because 0x0d "
-        "is not in the range of printable characters\n");
-    }
-    
-    /* check line feed */
-    if(0 != isprint(0x0a))
-    {
-        Fail("\nSucceeded when it should have failed because 0x0a "
-        "is not in the range of printable characters\n");
-    }
-    
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/isspace/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/isspace/test1/test1.cpp
deleted file mode 100644
index a5bdf2cb2187c4..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/isspace/test1/test1.cpp
+++ /dev/null
@@ -1,81 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Test #1 for the isspace function
-**
-**
-**==========================================================================*/
-
-
-
-#include <palsuite.h>
-
-struct testCase
-{
-    long result;
-    char avalue;
-};
-
-
-
-PALTEST(c_runtime_isspace_test1_paltest_isspace_test1, "c_runtime/isspace/test1/paltest_isspace_test1")
-{
-    int i=0;
-    long result = 0;
-
-    /*
-     * A structures of the testcases to be tested with
-     * isspace function
-     */
-    struct testCase testCases[] =
-    {
-           {1,'\n'},
-           {1,'\t'},
-           {1,'\r'},
-           {1,'\v'},
-           {1,'\f'},
-           {1,' '},
-           {0,'a'},
-           {0,'A'},
-           {0,'z'},
-           {0,'Z'},
-           {0,'r'},
-           {0,'R'},
-           {0,'0'},
-           {0,'*'},
-           {0,3}
-    };
-
-    /*
-     *  Initialize the PAL
-     */
-    if ( 0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    /* Loop through the testcases */
-    for (i=0; i<sizeof(testCases)/sizeof(struct testCase); i++)
-    {
-        result = isspace(testCases[i].avalue);
-        if ( ((testCases[i].result == 1) && (result==0)) ||
-             ((testCases[i].result ==0) && (result !=0)) )
-        {
-            Fail("ERROR: isspace() returned %d for %c instead of %d\n",
-                 result,
-                 testCases[i].avalue,
-                 testCases[i].result );
-        }
-    }
-
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/iswdigit/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/iswdigit/test1/test1.cpp
deleted file mode 100644
index d7ea8d5513a213..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/iswdigit/test1/test1.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c (iswdigit)
-**
-** Purpose: Tests the PAL implementation of the iswdigit function.
-**          Tests the passed parameter to iswdigit for being a 
-**          digit ('0' - '9'). Also passes non-digits to make sure
-**          iswdigit picks them up. 
-**          NOTE: There are three ASCII values that under Windows,
-**              iswdigit will return non-zero, indicating a digit. 
-**              These values are quite apparently not digits:
-**              178, 179, 185. 
-**          These are not tested.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_iswdigit_test1_paltest_iswdigit_test1, "c_runtime/iswdigit/test1/paltest_iswdigit_test1")
-{
-  
-    int result;  
-    int i;
-  
-    char16_t passTestCases[] = {'1','2','3','4','5','6','7','8','9'};
-    char16_t failTestCases[] = {'a','b','p','$','?',234};
-  
-    if ((PAL_Initialize(argc, argv)) != 0)
-    {
-        return (FAIL);
-    }
-  
-    /* Loop through each case. Testing if each is a digit. */
-    for(i = 0; i < sizeof(passTestCases) / sizeof(char16_t); i++)
-    {
-        result = iswdigit(passTestCases[i]);
-     
-        /* The return value is 'non-zero' indicates digit*/
-        if (result == 0)
-        {
-            Fail("ERROR: iswdigit returned \"%d\" instead indicating"
-                    " \"%c\" is not a digit\n",
-                    result,
-                    passTestCases[i]);
-        }
-    }      
-
-    /* Loop through each case. Testing if each is a not a digit. */
-    for(i = 0; i < sizeof(failTestCases) / sizeof(char16_t); i++)
-    {
-        result = iswdigit(failTestCases[i]);
-             
-        /* The return value is 'zero' indicates non-digit*/
-        if (result != 0)
-        {
-            Fail("ERROR: iswdigit returned \"%d\", indicating"
-                    " \"%c\" is a digit\n",
-                    result,
-                    failTestCases[i]);
-        }
-    }      
-    PAL_Terminate();
-    return (PASS);
-} 
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/iswprint/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/iswprint/test1/test1.cpp
deleted file mode 100644
index cdc249a62727ca..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/iswprint/test1/test1.cpp
+++ /dev/null
@@ -1,58 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests iswprint with all wide characters, ensuring they are 
-**          consistent with GetStringTypeExW.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_iswprint_test1_paltest_iswprint_test1, "c_runtime/iswprint/test1/paltest_iswprint_test1")
-{
-    WORD Info;
-    int ret;
-    int i;
-    WCHAR ch;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    for (i=0; i<=0xFFFF; i++)
-    {
-        ch = i;
-        ret = GetStringTypeExW(LOCALE_USER_DEFAULT, CT_CTYPE1, &ch, 1, &Info);
-        if (!ret)
-        {
-            Fail("GetStringTypeExW failed to get information for %#X!\n", ch);
-        }
-
-        ret = iswprint(ch);
-        if (Info & (C1_BLANK|C1_PUNCT|C1_ALPHA|C1_DIGIT))
-        {
-            if (!ret)
-            {
-                Fail("iswprint returned incorrect results for %#X: "
-                    "expected printable\n", ch);
-            }
-        }
-        else
-        {
-            if (ret)
-            {
-                Fail("iswprint returned incorrect results for %#X: "
-                    "expected non-printable\n", ch);
-            }
-        }
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/iswspace/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/iswspace/test1/test1.cpp
deleted file mode 100644
index 4d9de5d01a67e8..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/iswspace/test1/test1.cpp
+++ /dev/null
@@ -1,77 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests iswspace with a range of wide characters.
-**
-**
-**
-**==========================================================================*/
-
-
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_iswspace_test1_paltest_iswspace_test1, "c_runtime/iswspace/test1/paltest_iswspace_test1")
-{
-    int ret;
-    int i;
-
-    struct testChars
-    {
-        WCHAR charValue;
-        int result;
-    };
-
-    /* create an array of chars that test the range of possible characters */
-    struct testChars testChars1[] =    
-    {
-            {0x00,0}, /* null */
-            {0x09,1}, /* open circle */
-            {0x0D,1}, /* musical note */
-            {0x20,1}, /* space */
-            {0x3F,0}, /* ? */
-            {0x5E,0}, /* ^ */
-            {0x7B,0}, /* { */
-            {0x86,0}, /* a with circle on top */
-            {0x9F,0}, /* slanted f */
-            {0xC4,0}, /* long dash */
-            {0xE5,0} /* sigma */
-    };
-
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    for (i = 0; i < (sizeof(testChars1) / sizeof(struct testChars)); i++)
-    {
-
-        ret = iswspace(testChars1[i].charValue);
-
-        if((ret==0) && (testChars1[i].result != 0))
-            {
-            Fail("ERROR:  wide character %#X IS considered a space, "
-            "but iswspace did NOT indicate it was one with error %u.\n", 
-            testChars1[i].charValue,
-            GetLastError());
-            }
-
-        if((ret!=0) && (testChars1[i].result == 0))
-        {
-            Fail("ERROR: wide character %#X is NOT considered a space, " 
-            "but iswspace DID indicate it was a space with error %u.\n", 
-            testChars1[i].charValue,
-            GetLastError());               
-        }
-    }
-
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/iswupper/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/iswupper/test1/test1.cpp
deleted file mode 100644
index 7106aef6cd1b4d..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/iswupper/test1/test1.cpp
+++ /dev/null
@@ -1,90 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests the PAL implementation of the iswupper function
-**          Check that a number of characters return the correct
-**          values for whether they are upper case or not.
-**
-**
-**===================================================================*/
-
-#define UNICODE
-#include <palsuite.h>
-
-
-struct testCase
-{
-    int CorrectResult;
-    WCHAR character;
-};
-
-PALTEST(c_runtime_iswupper_test1_paltest_iswupper_test1, "c_runtime/iswupper/test1/paltest_iswupper_test1")
-{
-  
-    int result;  
-    int i;
-    
-    /* Note: 1 iff char =  A..Z
-             0 iff char =~ A..Z
-    */
-                       
-    struct testCase testCases[] = 
-        {
-            {1,  'A'},  /* Basic cases */
-            {1, 'Z'},
-            {0,  'b'},  /* Lower case */
-            {0,  '?'},  /* Characters without case */
-            {0,  230}
-        };
-  
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-  
-    /* Loop through each case. Check to see if each is upper case or
-       not.
-    */
-  
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-      
-        result = iswupper(testCases[i].character);
-     
-        /* The return value is 'non-zero' for success.  This if condition
-         * will still work if that non-zero isn't just 1 
-         */ 
-        if ( ((testCases[i].CorrectResult == 1) && (result == 0)) ||
-             ( (testCases[i].CorrectResult == 0) && (result != 0) ))
-        {
-            Fail("ERROR: iswupper returned %i instead of %i for "
-                   "character %c.\n",
-                   result,
-                   testCases[i].CorrectResult, 
-                   testCases[i].character);
-        }
-    
-    }      
-  
-  
-    PAL_Terminate();
-    return PASS;
-} 
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/isxdigit/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/isxdigit/test1/test1.cpp
deleted file mode 100644
index 8b49147fd6b137..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/isxdigit/test1/test1.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Run through every possible character.  For each time that
-** isxdigit returns:
-** 1, check through a list of the known hex characters to ensure that it
-** is really a hex char.  Also, when it returns 0, ensure that the character
-** isn't a hex character.
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(c_runtime_isxdigit_test1_paltest_isxdigit_test1, "c_runtime/isxdigit/test1/paltest_isxdigit_test1")
-{
-    int i;
-
-    /* Initialize the PAL */
-    if ( 0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    /* Loop through each character and call isxdigit for each character */
-    for (i=1; i<256; i++)
-    {
-
-        if (isxdigit(i) == 0)
-        {
-            if( ((i>=48) && (i<=57)) || ((i>=97) && (i<=102)) ||
-                ((i>=65) && (i<=70)) )
-            {
-                Fail("ERROR: isxdigit() returns true for '%c' (%d)\n", i, i);
-            }
-        }
-        else
-        {
-            if( ((i<48) && (i>58)) || ((i<97) && (i>102)) ||
-                ((i<65) && (i>70)) )
-            {
-                Fail("ERROR: isxdigit() returns false for '%c' (%d)\n", i, i);
-            }
-        }
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/llabs/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/llabs/test1/test1.cpp
deleted file mode 100644
index 09bf0670bf479b..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/llabs/test1/test1.cpp
+++ /dev/null
@@ -1,64 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Call llabs on a series of values -- negative, positive,
-** zero, and the largest negative value of an int64_t.  Ensure that
-** they are all changed properly to their absolute value.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    int64_t LongLongValue;
-    int64_t AbsoluteLongLongValue;
-};
-
-PALTEST(c_runtime_llabs_test1_paltest_llabs_test1, "c_runtime/llabs/test1/paltest_llabs_test1")
-{
-
-    int64_t result=0;
-    int i=0;
-
-    struct testCase testCases[] =
-        {
-            {1234,  1234},
-            {-1234, 1234},
-            {0,     0},
-            {-9223372036854775807LL, 9223372036854775807LL},  /* Max value to abs */
-            {9223372036854775807LL, 9223372036854775807LL}
-        };
-
-    if (0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-
-    /* Loop through each case. Call llabs on each int64_t and ensure that
-       the resulting value is correct.
-    */
-
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-        /* Absolute value on an int64_t */
-        result = llabs(testCases[i].LongLongValue);
-
-        if (testCases[i].AbsoluteLongLongValue != result)
-        {
-            Fail("ERROR: llabs took the absolute value of '%d' to be '%d' "
-                 "instead of %d.\n",
-                 testCases[i].LongLongValue,
-                 result,
-                 testCases[i].AbsoluteLongLongValue);
-        }
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/memchr/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/memchr/test1/test1.cpp
deleted file mode 100644
index a7e44dbd911f1a..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/memchr/test1/test1.cpp
+++ /dev/null
@@ -1,121 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests the PAL implementation of the memchr function.
-**          Create a string buffer, and check for a number of
-**          characters in it. Test to ensure it returns NULL if
-**          it can't find the character, and that the size argument
-**          works properly.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-   char *result;
-   char string[50];
-   int character;
-   int length;
-};
-
-
-PALTEST(c_runtime_memchr_test1_paltest_memchr_test1, "c_runtime/memchr/test1/paltest_memchr_test1")
-{
-    int i = 0;
-    char *result = NULL;
-
-    /*
-     * this structure includes several strings to be tested with
-     * memchr function and the expected results
-     */
-
-    struct testCase testCases[]=
-    {
-        {"st","corn cup cat cream coast",'s',23}, 
-                                   /* single instance of char                 */
-        {"st","corn cup cat cream coast",'s',24}, 
-                                   /* single inst, inst< exact length         */
-        {"q","corn cup cat cream coastq",'q',25},
-                                   /* single inst at end, inst=exact length   */
-        {"q","corn cup cat cream coastq",'q',26},
-                                   /* single inst at end, inst<length, 
-                                                           length>len(string) */
-        {"st","corn cup cat cream coast",115,24},
-                                   /* single int inst, inst<exact length      */
-        {"corn cup cat cream coast","corn cup cat cream coast",'c',24},
-                                   /* multi-inst, inst=1, exact length        */
-        {"corn cup cat cream coast","corn cup cat cream coast",'c',1},
-                                   /* multi-inst, inst = length, length=1     */
-        {"is is a test","This is a test",105,14},  
-                                   /* single int inst, exact length           */
-        {"is is a test","This is a test",'i',14},  
-                                   /* double inst, exact length               */
-        {"a test","This is a test",'a',9}, 
-                                   /* single instance instance = length       */
-        {NULL,"This is a test",'b',14}, 
-                                   /* no instance exact length                */
-        {NULL,"This is a test",'a',8},  
-                                   /* single instance - < length              */
-        {NULL,"This is a test",121,14}, 
-                                   /* single instance - exact length          */
-        {" is a test of the function","This is a test of the function",
-         ' ',17}                   /* single inst<length, len(string)>length  */
-    };
-
-
-    /* Initialize the PAL */
-    if ( 0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    /* Loop through the testcases in the structure */
-    for (i=0; i< sizeof(testCases)/sizeof(struct testCase); i++)
-    {
-        /* Need to type cast function in order to compare the result */
-        result = (char *)memchr(testCases[i].string,
-                 testCases[i].character,testCases[i].length);
-
-        if (result==NULL)
-        {
-           if (testCases[i].result != NULL)
-           {
-               Fail("ERROR:  Expected memcmp to return \"%s\" instead of"
-                    " NULL\n", testCases[i].result);
-           }
-        }
-        else
-        {
-           if (strcmp(result,testCases[i].result)!=0 )
-
-           {
-              Fail("ERROR:  Expected memcmp to return \"%s\" instead of"
-                    " \"%s\"\n", testCases[i].result, result);
-           }
-
-        }
-     }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/memcmp/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/memcmp/test1/test1.cpp
deleted file mode 100644
index c1a17f30a659bb..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/memcmp/test1/test1.cpp
+++ /dev/null
@@ -1,56 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Check that memcmp find identical buffers to be identical,
-**          and that it correctly orders different buffers.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_memcmp_test1_paltest_memcmp_test1, "c_runtime/memcmp/test1/paltest_memcmp_test1")
-{
-
-    char testA[] = "aaaaaaaaaaaaaaaaaaaa";
-    char testB[] = "aaaaaaaaaaaaaaaaaaaa";
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    if (!(memcmp(testA, testB, 20) == 0))
-    {
-        Fail("memcmp compared two identical buffers and found them to "
-             "differ.\n");
-    }
-    testB[3] = 'b';
-
-    if (!(memcmp(testA, testB, 20) < 0)
-    || !(memcmp(testB, testA, 20) >0 ))
-    {
-        Fail("memcmp compared two buffers with different contents, and"
-             " did not order them correctly.\n");
-    }
-    
-    if (memcmp(testA, testB, 0) != 0)
-    {
-        Fail("memcmp didn't return 0 when comparing buffers of length 0.\n");
-    }
-  
-    PAL_Terminate();
-    return PASS;
-}
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/memmove/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/memmove/test1/test1.cpp
deleted file mode 100644
index 476ba01f5f276c..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/memmove/test1/test1.cpp
+++ /dev/null
@@ -1,115 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Test that memmove correctly copies text from one buffer
-**          to another even when the buffers overlap.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_memmove_test1_paltest_memmove_test1, "c_runtime/memmove/test1/paltest_memmove_test1")
-{
-    char testA[11] = "abcdefghij";
-    char testB[15] = "aabbccddeeffgg";
-    char testC[15] = "aabbccddeeffgg";
-    char testD[15] = "aabbccddeeffgg";
-    char insString[4] = "zzz";
-    char *retVal;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    /* move a string onto itself */
-    retVal = (char *)memmove(testA + 2, testA, 8);
-    if (retVal != testA + 2)
-    {
-        Fail("The return value should have been the value of the destination"
-             "pointer, but wasn't\n");
-    }
-
-    /*Check the most likely error*/
-    if (memcmp(testA, "ababababab", 11) == 0)
-    {
-        Fail("memmove should have saved the characters in the region of"
-             " overlap between source and destination, but didn't.\n");
-    }
-
-    if (memcmp(testA, "ababcdefgh", 11) != 0)
-    {
-        /* not sure what exactly went wrong. */
-        Fail("memmove was called on a region containing the characters"
-             " \"abcdefghij\".  It was to move the first 8 positions to"
-             " the last 8 positions, giving the result \"ababcdefgh\". "
-             " Instead, it gave the result \"%s\".\n", testA);
-    }
-
-    /* move a string to the front of testB */
-    retVal = (char *)memmove(testB, insString, 3);
-    if(retVal != testB)
-    {
-        Fail("memmove: The function did not return the correct "
-        "string.\n");
-    }
-
-    if(memcmp(testB, "zzzbccddeeffgg",15) != 0)
-    {
-        Fail("memmove: The function failed to move the string "
-        "correctly.\n");
-    }
-
-
-    /* move a string to the middle of testC */
-    retVal = (char*)memmove(testC+5, insString, 3);
-    if(retVal != testC+5)
-    {
-        Fail("memmove: The function did not return the correct "
-        "string.\n");
-    }
-
-    if(memcmp(testC, "aabbczzzeeffgg",15) != 0)
-    {
-        Fail("memmove: The function failed to move the string "
-        "correctly.\n");
-    }
-
-
-    /* move a string to the end of testD */
-    retVal = (char*)memmove(testD+11, insString, 3);
-    if(retVal != testD+11)
-    {
-        Fail("memmove: The function did not return the correct "
-        "string.\n");
-    }
-
-    if(memcmp(testD, "aabbccddeefzzz",15) != 0)
-    {
-        Fail("memmove: The function failed to move the string "
-        "correctly.\n");
-    }
-
-    PAL_Terminate();
-    return PASS;
-
-}
-
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/memset/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/memset/test1/test1.cpp
deleted file mode 100644
index ee8d92fd4ab538..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/memset/test1/test1.cpp
+++ /dev/null
@@ -1,59 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Check that memset correctly fills a destination buffer
-**          without overflowing it.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_memset_test1_paltest_memset_test1, "c_runtime/memset/test1/paltest_memset_test1")
-{
-
-    char testA[22] = "bbbbbbbbbbbbbbbbbbbbb";
-    char *retVal;
-
-    int i;
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    retVal = (char *)memset(testA, 'a', 20);
-    if (retVal != testA) 
-    {
-        Fail("memset should have returned the value of the destination"
-             "pointer, but didn't");
-    }
-
-    for(i = 0; i<20; i++)
-    {
-        if (testA[i]!= 'a')
-        {
-            Fail("memset didn't set the destination bytes.\n");
-        }
-    }
-    if (testA[20] == 'a')
-    {
-        Fail("memset overfilled the destination buffer.\n");
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strcat/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strcat/test1/test1.cpp
deleted file mode 100644
index 7c8ec61fe9f6e9..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strcat/test1/test1.cpp
+++ /dev/null
@@ -1,65 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose:
-** Concatenate three strings into one string.  Each time, check to ensure 
-** the pointer returned was what we expected.  When finished, compare the 
-** newly formed string to what it should be to ensure no characters were 
-** lost.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(c_runtime_strcat_test1_paltest_strcat_test1, "c_runtime/strcat/test1/paltest_strcat_test1")
-{
-    char dest[80];
-    char *test = "foo bar baz";
-    char *str1 = "foo ";
-    char *str2 = "bar ";
-    char *str3 = "baz";
-    char *ptr;
-
-    
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    dest[0] = 0;
-
-    ptr = strcat(dest, str1);
-    if (ptr != dest)
-    {
-        Fail("ERROR: Expected strcat to return ptr to %p, got %p", dest, ptr);
-    }
-
-    ptr = strcat(dest, str2);
-    if (ptr != dest)
-    {
-        Fail("ERROR: Expected strcat to return ptr to %p, got %p", dest, ptr);
-    }
-
-    ptr = strcat(dest, str3);
-    if (ptr != dest)
-    {
-        Fail("ERROR: Expected strcat to return ptr to %p, got %p", dest, ptr);
-    }
-
-    if (strcmp(dest, test) != 0)
-    {
-        Fail("ERROR: Expected strcat to give \"%s\", got \"%s\"\n", 
-            test, dest);
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strchr/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strchr/test1/test1.cpp
deleted file mode 100644
index 0c706b8b538e95..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strchr/test1/test1.cpp
+++ /dev/null
@@ -1,85 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose:
-** Test this on a character which is in a string, and ensure the pointer
-** points to that character.  Then check the string for the null character,
-** which the return pointer should point to.  Then search for a character not
-** in the string and check that the return value is NULL.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    int result;
-    char string[50];
-    int character;
-};
-
-
-
-PALTEST(c_runtime_strchr_test1_paltest_strchr_test1, "c_runtime/strchr/test1/paltest_strchr_test1")
-{
-    int i = 0;
-    char *result;
-
-    /*
-     * this structure includes several strings to be tested with
-     * strchr function and the expected results
-     */
-
-    struct testCase testCases[]=
-    {
-        {22,"corn cup cat cream coast",'s'},
-        {10,"corn cup cat cream coast",'a'},
-        {2,"This is a test",'i'},
-        {10,"This is a test",'t'},
-        {'\0',"This is a test",'b'},/* zero used instead of NULL */
-        {'\0',"This is a test",121},/* zero used instead of NULL */
-        {4,"This is a test of the function",' '},
-        {25,"This is a test of the function",'c'},
-        {'\0',"This is a test of the function",'C'},
-        {24,"corn cup cat cream coast", '\0'}/* zero used instead of NULL */
-    };
-
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    /* Loop through the structure and test each case */
-
-    for (i=0; i< sizeof(testCases)/sizeof(struct testCase); i++)
-    {
-       result = strchr(testCases[i].string,testCases[i].character);
-       if (result==NULL)
-       {
-          if (testCases[i].result != 0)
-          {
-              Fail("Expected strchr() to return \"%s\" instead of NULL!\n",
-                   testCases[i].string + testCases[i].result);
-          }
-       }
-       else
-       {
-          if (result != testCases[i].string + testCases[i].result)
-          {
-              Fail("Expected strchr() to return \"%s\" instead of \"%s\"!\n",
-                   testCases[i].string + testCases[i].result, result);
-          }
-        }
-
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strcmp/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strcmp/test1/test1.cpp
deleted file mode 100644
index dadbeb5cb5b334..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strcmp/test1/test1.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose:
-** Compare a number of different strings against each other, ensure that the
-** three return values are given at the appropriate times.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-typedef struct
-{
-    int result;
-    char string1[50];
-    char string2[50];
-} testCase;
-
-PALTEST(c_runtime_strcmp_test1_paltest_strcmp_test1, "c_runtime/strcmp/test1/paltest_strcmp_test1")
-{
-    testCase testCases[]=
-    {
-        {0,"Hello","Hello"},
-        {1,"hello","Hello"},
-        {-1,"Hello","hello"},
-        {0,"0Test","0Test"},
-        {0,"***???","***???"},
-        {0,"Testing the string for string comparison","Testing the string for "
-            "string comparison"},
-        {-1,"Testing the string for string comparison","Testing the string for "
-            "string comparsioa"},
-        {1,"Testing the string for string comparison","Testing the string for "
-            "comparison"},
-        {-1,"aaaabbbbb","aabcdefeccg"}
-    };
-
-    int i = 0;
-    int result = 0;
-    
-    /*
-     *  Initialize the PAL
-     */
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    /* Loop through structure and test each case */
-    for (i=0; i < sizeof(testCases)/sizeof(testCase); i++)
-    {
-        result = strcmp(testCases[i].string1,testCases[i].string2);
-
-        /* Compare returned value */
-        if( ((result == 0) && (testCases[i].result !=0)) ||
-            ((result <0) && (testCases[i].result !=-1)) ||
-            ((result >0) && (testCases[i].result !=1)) )
-        {
-           Fail("ERROR:  strcmp returned %d instead of %d\n",
-                result, testCases[i].result);
-        }
-
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strcpy/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strcpy/test1/test1.cpp
deleted file mode 100644
index acb1e68b013e99..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strcpy/test1/test1.cpp
+++ /dev/null
@@ -1,50 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose:
-** Call the function to copy into an empty buffer.  Check that the return value
-** is pointing at the destination buffer.  Also compare the string copied to
-** the original string, to ensure they are the same.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(c_runtime_strcpy_test1_paltest_strcpy_test1, "c_runtime/strcpy/test1/paltest_strcpy_test1")
-{
-    char dest[80];
-    char *result = "foo";
-    char str[] = {'f','o','o',0,'b','a','r',0};
-    char *ret;
-
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    ret = strcpy(dest, str);
-
-    if (ret != dest)
-    {
-        Fail("Expected strcpy to return %p, got %p!\n", dest, ret);
-
-    }
-
-    if (strcmp(dest, result) != 0)
-    {
-        Fail("Expected strcpy to give \"%s\", got \"%s\"!\n", result, dest);
-    }
-
-
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strlen/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strlen/test1/test1.cpp
deleted file mode 100644
index b19b3fec34457f..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strlen/test1/test1.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: 
-** Check the length of a string and the length of a 0 character string to 
-** see that this function returns the correct values for each.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(c_runtime_strlen_test1_paltest_strlen_test1, "c_runtime/strlen/test1/paltest_strlen_test1")
-{
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    if (strlen("foo") != 3)
-        Fail("ERROR: strlen(\"foo\") != 3\n");
-
-    if (strlen("") != 0)
-        Fail("ERROR: strlen(\"\") != 0\n");
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strncat/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strncat/test1/test1.cpp
deleted file mode 100644
index 240a78f9fef276..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strncat/test1/test1.cpp
+++ /dev/null
@@ -1,76 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: 
-** Concatenate a few strings together, setting different lengths to be 
-** used for each one.  Check to ensure the pointers which are returned are
-** correct, and that the final string is what was expected.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(c_runtime_strncat_test1_paltest_strncat_test1, "c_runtime/strncat/test1/paltest_strncat_test1")
-{
-    char dest[80];
-    char *test = "foo barbaz";
-    char *str1 = "foo ";
-    char *str2 = "bar ";
-    char *str3 = "baz";
-    char *ptr;
-    int i;
-
-    
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    dest[0] = 0;
-    for (i=1; i<80; i++)
-    {
-        dest[i] = 'x';
-    }
-
-    ptr = strncat(dest, str1, strlen(str1));
-    if (ptr != dest)
-    {
-        Fail("ERROR: Expected strncat to return ptr to %p, got %p", dest, ptr);
-    }
-
-    ptr = strncat(dest, str2, 3);
-    if (ptr != dest)
-    {
-        Fail("ERROR: Expected strncat to return ptr to %p, got %p", dest, ptr);
-    }
-    if (dest[7] != 0)
-    {
-        Fail("ERROR: strncat did not place a terminating NULL!");
-    }
-
-    ptr = strncat(dest, str3, 20);
-    if (ptr != dest)
-    {
-        Fail("ERROR: Expected strncat to return ptr to %p, got %p", dest, ptr);
-    }
-    if (strcmp(dest, test) != 0)
-    {
-        Fail("ERROR: Expected strncat to give \"%s\", got \"%s\"\n", 
-            test, dest);
-    }
-    if (dest[strlen(test)+1] != 'x')
-    {
-        Fail("strncat went out of bounds!\n");
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strncmp/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strncmp/test1/test1.cpp
deleted file mode 100644
index c39498739f1df6..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strncmp/test1/test1.cpp
+++ /dev/null
@@ -1,78 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: 
-** Test to ensure all three possible return values are given under the 
-** appropriate circumstance.  Also, uses different sizes, to only compare
-** portions of strings, checking to make sure these return the correct value.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-typedef struct
-{
-    int result;
-    char string1[50];
-    char string2[50];
-    int number;
-} testCase;
-
-PALTEST(c_runtime_strncmp_test1_paltest_strncmp_test1, "c_runtime/strncmp/test1/paltest_strncmp_test1")
-{
-    testCase testCases[]=
-    {
-        {0,"Hello","Hello",5},
-        {1,"hello","Hello",3},
-        {-1,"Hello","hello",5},
-        {0,"heLLo","heLLo",5},
-        {1,"hello","heLlo",5},
-        {-1,"heLlo","hello",5},
-        {0,"0Test","0Test",5},
-        {0,"***???","***???",6},
-        {0,"Testing the string for string comparison","Testing the string for "
-            "string comparison",40},
-        {-1,"Testing the string for string comparison","Testing the string for "
-            "string comparsioa",40},
-        {1,"Testing the string for string comparison","Testing the string for "
-            "comparison",34},
-        {0,"aaaabbbbb","aabcdefeccg",2},
-        {0,"abcd","abcd",10}
-    };
-
-    int i=0;
-    int iresult=0;
-    
-    /*
-     *  Initialize the PAL
-     */
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    for (i=0; i< sizeof(testCases)/sizeof(testCase); i++)
-    {
-        iresult = strncmp(testCases[i].string1,testCases[i].string2,
-                          testCases[i].number);
-
-        if( ((iresult == 0) && (testCases[i].result !=0)) ||
-            ((iresult <0) && (testCases[i].result !=-1)) ||
-            ((iresult >0) && (testCases[i].result !=1)) )
-
-    {
-             Fail("ERROR: strncmp returned %d instead of %d\n",
-                  iresult, testCases[i].result);
-    }
-
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strncpy/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strncpy/test1/test1.cpp
deleted file mode 100644
index b934d3cfb65546..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strncpy/test1/test1.cpp
+++ /dev/null
@@ -1,84 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose:
-** Test to see that you can copy a portion of a string into a new buffer.
-** Also check that the strncpy function doesn't overflow when it is used.
-** Finally check that if the number of characters given is greater than the 
-** amount to copy, that the destination buffer is padded with NULLs.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(c_runtime_strncpy_test1_paltest_strncpy_test1, "c_runtime/strncpy/test1/paltest_strncpy_test1")
-{
-    char dest[80];
-    char *result = "foobar";
-    char *str = "foobar\0baz";
-    char *ret;
-    int i;
-    
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    for (i=0; i<80; i++)
-    {
-        dest[i] = 'x';
-    }
-
-    ret = strncpy(dest, str, 3);
-    if (ret != dest)
-    {
-        Fail("Expected strncpy to return %p, got %p!\n", dest, ret);        
-    }
-
-    if (strncmp(dest, result, 3) != 0)
-    {
-        Fail("Expected strncpy to give \"%s\", got \"%s\"!\n", result, dest);
-    }
-
-    if (dest[3] != 'x')
-    {
-        Fail("strncpy overflowed!\n");
-    }
-
-    ret = strncpy(dest, str, 40);
-    if (ret != dest)
-    {
-        Fail("Expected strncpy to return %p, got %p!\n", dest, ret);        
-    }
-
-    if (strcmp(dest, result) != 0)
-    {
-        Fail("Expected strncpy to give \"%s\", got \"%s\"!\n", result, dest);
-    }
-
-    for (i=strlen(str); i<40; i++)
-    {
-        if (dest[i] != 0)
-        {
-            Fail("strncpy failed to pad the destination with NULLs!\n");
-        }
-    }
-
-    if (dest[40] != 'x')
-    {
-        Fail("strncpy overflowed!\n");
-    }
-    
-
-
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strpbrk/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strpbrk/test1/test1.cpp
deleted file mode 100644
index b2b90edea7e934..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strpbrk/test1/test1.cpp
+++ /dev/null
@@ -1,84 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose:
-** Search a string for characters in a given character set and ensure the 
-** pointer returned points to the first occurrence.  Check to see that the
-** function returns NULL if the character is not found.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    char *result;
-    char *string1;
-    char *string2;
-};
-
-PALTEST(c_runtime_strpbrk_test1_paltest_strpbrk_test1, "c_runtime/strpbrk/test1/paltest_strpbrk_test1")
-{
-    char *ptr = NULL;
-    int i = 0;
-
-    /*
-     * this structure includes several strings to be tested with
-     * strpbk function and the expected results
-     */
-
-    struct testCase testCases[] =
-    {
-        {"t cream coast","corn cup cat cream coast","sit"},
-        {"eam coast","corn cup cat cream coast","like"},
-        {"is is a test","This is a test","circle"},
-        {"a test","This is a test","way"},
-        {NULL,"This is a test","boo"},
-        {NULL,"This is a test","123"},
-        {" is a test of the function","This is a test of the function",
-         "zzz xx"}
-    };
-
-    
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    /* A loop to go through the testcases in the structure */
-
-    for (i=0; i< sizeof(testCases)/sizeof(struct testCase); i++)
-    {
-        ptr = strpbrk(testCases[i].string1,testCases[i].string2);
-        if (ptr==NULL)
-        {
-            if (testCases[i].result != NULL)
-            {
-                Fail("Expected strpbrk() to return %s, got NULL!\n",
-                     testCases[i].result);
-            }
-        }
-        else
-        {
-            if (strcmp(ptr,testCases[i].result)!=0 )
-
-            {
-                Fail("Expected strpbrk() to return %s, got %s!\n",
-                     testCases[i].result,ptr);
-            }
-
-        }
-
-     }
-
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strrchr/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strrchr/test1/test1.cpp
deleted file mode 100644
index 85e53eb2a8631a..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strrchr/test1/test1.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: \
-** Search a string for a given character.  Search for a character contained
-** in the string, and ensure the pointer returned points to it.  Then search
-** for the null character, and ensure the pointer points to that.  Finally 
-** search for a character which is not in the string and ensure that it 
-** returns NULL.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(c_runtime_strrchr_test1_paltest_strrchr_test1, "c_runtime/strrchr/test1/paltest_strrchr_test1")
-{
-    char *str = "foo bar baz";
-    char *ptr;
-
-    
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    ptr = strrchr(str, 'b');
-    if (ptr != str + 8)
-    {
-        Fail("Expected strrchr() to return %p, got %p!\n", str + 8, ptr);
-    }
-
-    ptr = strrchr(str, 0);
-    if (ptr != str + 11)
-    {
-        Fail("Expected strrchr() to return %p, got %p!\n", str + 11, ptr);
-    }
-
-    ptr = strrchr(str, 'x');
-    if (ptr != NULL)
-    {
-        Fail("Expected strrchr() to return NULL, got %p!\n", ptr);
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/strstr/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/strstr/test1/test1.cpp
deleted file mode 100644
index e50d5bda12b819..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/strstr/test1/test1.cpp
+++ /dev/null
@@ -1,82 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source:  test1.c
-**
-** Purpose: 
-** Check three cases of searching for a string within a string.  First when
-** the string is contained, check that the pointer returned points to it.
-** Then when it isn't contained, ensure it returns null.  And when the string
-** we're searching for is empty, it should return a pointer to the string 
-** we're searching through.Test #1 for the strstr function
-**
-**
-**==========================================================================*/
-
-
-
-#include <palsuite.h>
-
-
-struct testCase
-{
-    char *result;
-    char *string1;
-    char *string2;
-
-};
-
-PALTEST(c_runtime_strstr_test1_paltest_strstr_test1, "c_runtime/strstr/test1/paltest_strstr_test1")
-{
-    int i=0;
-    char *ptr=NULL;
-
-    struct testCase testCases[]=
-    {
-        {"is is a test", "This is a test","is"},
-        {"fghijkl","abcdefghijkl","fgh"},
-        {NULL,"aabbccddeeffgg","h"},
-        {NULL,"aabb", "eeeeeee"},
-        {"AAA", "BBddfdaaaaAAA","A"},
-        {"fdaaaaAAA", "BBddfdaaaaAAA","f"},
-        {"aadfsadfas","aadfsadfas",""},
-        {NULL,"","ccc"}
-    };
-
-    /*
-     *  Initialize the PAL
-     */
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    for (i=0; i<sizeof(testCases)/sizeof(struct testCase); i++)
-    {
-        ptr = strstr(testCases[i].string1,testCases[i].string2);
-        if (ptr==NULL)
-	{
-           if (testCases[i].result != NULL)
-           {
-	       Fail("ERROR: strstr returned incorrect value\n"
-		    "Expected a pointer to \"%s\" , got a pointer to NULL\n",
-		    testCases[i].result);
-	   }
-        }
-        else
-        {
-           if (strcmp(testCases[i].result,ptr) != 0)
-	   {
-	       Fail("ERROR: strstr returned incorrect value\n"
-		    "Expected a pointer to \"%s\" , got a pointer to \"%s\"\n",
-		    testCases[i].result, ptr);
-           }
-        }
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/tolower/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/tolower/test1/test1.cpp
deleted file mode 100644
index b6723786245da2..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/tolower/test1/test1.cpp
+++ /dev/null
@@ -1,78 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests the PAL implementation of the tolower function.
-**          Check that the tolower function makes capital character
-**          lower case. Also check that it has no effect on lower
-**          case letters and special characters.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    int lower;
-    int start;
-};
-
-PALTEST(c_runtime_tolower_test1_paltest_tolower_test1, "c_runtime/tolower/test1/paltest_tolower_test1")
-{
-  
-    int result;  
-    int i;
-
-    struct testCase testCases[] = 
-        {
-            {'a',  'A'},  /* Basic cases */
-            {'z', 'Z'},
-            {'b',  'b'},  /* Lower case */
-            {'?',  '?'},  /* Characters without case */
-            {230,  230}
-        };
-  
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    /* Loop through each case.  Convert each character to lower case 
-       and then compare to ensure that it is the correct value.
-    */
-  
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-        /*Convert to lower case*/
-        result = tolower(testCases[i].start);
-     
-        if (testCases[i].lower != result)
-        {
-            Fail("ERROR: tolower lowered \"%i\" to %i instead of %i.\n",
-                   testCases[i].start, result, testCases[i].lower);
-        }
-    
-    }      
-  
-  
-    PAL_Terminate();
-    return PASS;
-} 
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/toupper/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/toupper/test1/test1.cpp
deleted file mode 100644
index 1683aa3b9fc6d1..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/toupper/test1/test1.cpp
+++ /dev/null
@@ -1,63 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:    test1.c (toupper)
-**
-**
-** Purpose:   Tests the PAL implementation of the toupper function.
-**            Check that the toupper function makes lower case
-**            character a capital. Also check that it has no effect
-**            on upper case letters and special characters.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    int upper;
-    int start;
-};
-
-PALTEST(c_runtime_toupper_test1_paltest_toupper_test1, "c_runtime/toupper/test1/paltest_toupper_test1")
-{
-  
-    int result;  
-    int i;
-
-    struct testCase testCases[] = 
-        {
-            {'A', 'a'},   /* Basic cases */
-            {'Z', 'z'},
-            {'B', 'B'},   /* Upper case */
-            {'%',  '%'},  /* Characters without case */
-            {157,  157}
-        };
-  
-    if ((PAL_Initialize(argc, argv)) != 0)
-    {
-        return FAIL;
-    }
-
-
-    /* Loop through each case.  Convert each character to upper case 
-       and then compare to ensure that it is the correct value.
-    */
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-        /*Convert to upper case*/
-        result = toupper(testCases[i].start);
-     
-        if (testCases[i].upper != result)
-        {
-            Fail("ERROR: toupper capitalized \"%c\" to %c instead of %c.\n",
-                   testCases[i].start, result, testCases[i].upper);
-        }
-    }
-  
-    PAL_Terminate();
-    return PASS;
-} 
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/towlower/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/towlower/test1/test1.cpp
deleted file mode 100644
index e17aad88bc46d8..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/towlower/test1/test1.cpp
+++ /dev/null
@@ -1,78 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:  test1.c
-**
-** Purpose: Tests the PAL implementation of the towlower function.
-**          Check that the tolower function makes capital character
-**          lower case. Also check that it has no effect on lower
-**          case letters and special characters.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    WCHAR lower;
-    WCHAR start;
-};
-
-PALTEST(c_runtime_towlower_test1_paltest_towlower_test1, "c_runtime/towlower/test1/paltest_towlower_test1")
-{
-  
-    int result;  
-    int i;
-
-    struct testCase testCases[] = 
-        {
-            {'a',  'A'},  /* Basic cases */
-            {'z', 'Z'},
-            {'b',  'b'},  /* Lower case */
-            {'?',  '?'},  /* Characters without case */
-            {230,  230}
-        };
-  
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    /* Loop through each case.  Convert each character to lower case 
-       and then compare to ensure that it is the correct value.
-    */
-  
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-        /*Convert to lower case*/
-        result = towlower(testCases[i].start);
-     
-        if (testCases[i].lower != result)
-        {
-            Fail("ERROR: towlower lowered \"%c\" to %c instead of %c.\n", 
-                testCases[i].start, result, testCases[i].lower);
-        }
-    
-    }      
-  
-  
-    PAL_Terminate();
-    return PASS;
-} 
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/c_runtime/towupper/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/c_runtime/towupper/test1/test1.cpp
deleted file mode 100644
index d2fd880d17148a..00000000000000
--- a/src/coreclr/pal/tests/palsuite/c_runtime/towupper/test1/test1.cpp
+++ /dev/null
@@ -1,64 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=====================================================================
-**
-** Source:   test1.c(towupper)
-**
-**
-** Purpose:  Tests the PAL implementation of the towupper function.
-**           Check that the towupper function makes lower case
-**           character a capital. Also check that it has no effect
-**           on upper case letters and special characters.
-**
-**
-**===================================================================*/
-
-#include <palsuite.h>
-
-struct testCase
-{
-    WCHAR upper;
-    WCHAR start;
-};
-
-PALTEST(c_runtime_towupper_test1_paltest_towupper_test1, "c_runtime/towupper/test1/paltest_towupper_test1")
-{
-  
-    int result;  
-    int i;
-
-    struct testCase testCases[] = 
-        {
-            {'A', 'a'},  /* Basic cases */
-            {'Z', 'z'},
-            {'B', 'B'},  /* Upper case */
-            {'%', '%'},  /* Characters without case */
-            {157,  157}
-        };
-  
-    if ((PAL_Initialize(argc, argv)) != 0)
-    {
-        return FAIL;
-    }
-
-
-    /* Loop through each case.  Convert each character to upper case 
-       and then compare to ensure that it is the correct value.
-    */
-  
-    for(i = 0; i < sizeof(testCases) / sizeof(struct testCase); i++)
-    {
-        /*Convert to upper case*/
-        result = towupper(testCases[i].start);
-     
-        if (testCases[i].upper != result)
-        {
-            Fail("ERROR: towupper capitalized \"%c\" to %c instead of %c.\n",
-                    testCases[i].start, result, testCases[i].upper);
-        }
-    }      
-  
-    PAL_Terminate();
-    return PASS;
-} 
diff --git a/src/coreclr/pal/tests/palsuite/common/palsuite.cpp b/src/coreclr/pal/tests/palsuite/common/palsuite.cpp
index 1b5f826dd8d9f9..88fe3fa77a2974 100644
--- a/src/coreclr/pal/tests/palsuite/common/palsuite.cpp
+++ b/src/coreclr/pal/tests/palsuite/common/palsuite.cpp
@@ -13,6 +13,7 @@
 
 #include "palsuite.h"
 #include "minipal/time.h"
+#include "minipal/utf8.h"
 
 const char* szTextFile = "text.txt";
 
@@ -24,13 +25,14 @@ WCHAR* convert(const char * aString)
 
     if (aString != nullptr)
     {
-        int size = MultiByteToWideChar(CP_ACP,0,aString,-1,NULL,0);
+        size_t length = strlen(aString) + 1;
+        size_t size = minipal_get_length_utf8_to_utf16(aString, length, 0);
         wideBuffer = (WCHAR*) malloc(size*sizeof(WCHAR));
         if (wideBuffer == NULL)
         {
             Fail("ERROR: Unable to allocate memory!\n");
         }
-        MultiByteToWideChar(CP_ACP,0,aString,-1,wideBuffer,size);
+        minipal_convert_utf8_to_utf16(aString, length, (CHAR16_T*)wideBuffer, size, 0);
     }
 
     return wideBuffer;
@@ -38,16 +40,14 @@ WCHAR* convert(const char * aString)
 
 char* convertC(const WCHAR * wString)
 {
-    int size;
-    char * MultiBuffer = NULL;
-
-    size = WideCharToMultiByte(CP_ACP,0,wString,-1,MultiBuffer,0,NULL,NULL);
-    MultiBuffer = (char*) malloc(size);
+    size_t length = wcslen(wString) + 1;
+    size_t size = minipal_get_length_utf16_to_utf8((const CHAR16_T*)wString, length, 0);
+    char * MultiBuffer = (char*) malloc(size);
     if (MultiBuffer == NULL)
     {
         Fail("ERROR: Unable to allocate memory!\n");
     }
-    WideCharToMultiByte(CP_ACP,0,wString,-1,MultiBuffer,size,NULL,NULL);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)wString, length, MultiBuffer, size, 0);
     return MultiBuffer;
 }
 
diff --git a/src/coreclr/pal/tests/palsuite/compilableTests.txt b/src/coreclr/pal/tests/palsuite/compilableTests.txt
index 76c53595367098..b358bd693f36f3 100644
--- a/src/coreclr/pal/tests/palsuite/compilableTests.txt
+++ b/src/coreclr/pal/tests/palsuite/compilableTests.txt
@@ -1,20 +1,3 @@
-c_runtime/atof/test1/paltest_atof_test1
-c_runtime/atoi/test1/paltest_atoi_test1
-c_runtime/isalnum/test1/paltest_isalnum_test1
-c_runtime/isalpha/test1/paltest_isalpha_test1
-c_runtime/isdigit/test1/paltest_isdigit_test1
-c_runtime/isprint/test1/paltest_isprint_test1
-c_runtime/isprint/test2/paltest_isprint_test2
-c_runtime/isspace/test1/paltest_isspace_test1
-c_runtime/iswdigit/test1/paltest_iswdigit_test1
-c_runtime/iswspace/test1/paltest_iswspace_test1
-c_runtime/iswupper/test1/paltest_iswupper_test1
-c_runtime/isxdigit/test1/paltest_isxdigit_test1
-c_runtime/llabs/test1/paltest_llabs_test1
-c_runtime/memchr/test1/paltest_memchr_test1
-c_runtime/memcmp/test1/paltest_memcmp_test1
-c_runtime/memmove/test1/paltest_memmove_test1
-c_runtime/memset/test1/paltest_memset_test1
 c_runtime/sscanf_s/test1/paltest_sscanf_test1
 c_runtime/sscanf_s/test10/paltest_sscanf_test10
 c_runtime/sscanf_s/test11/paltest_sscanf_test11
@@ -32,21 +15,6 @@ c_runtime/sscanf_s/test6/paltest_sscanf_test6
 c_runtime/sscanf_s/test7/paltest_sscanf_test7
 c_runtime/sscanf_s/test8/paltest_sscanf_test8
 c_runtime/sscanf_s/test9/paltest_sscanf_test9
-c_runtime/strcat/test1/paltest_strcat_test1
-c_runtime/strchr/test1/paltest_strchr_test1
-c_runtime/strcmp/test1/paltest_strcmp_test1
-c_runtime/strcpy/test1/paltest_strcpy_test1
-c_runtime/strlen/test1/paltest_strlen_test1
-c_runtime/strncat/test1/paltest_strncat_test1
-c_runtime/strncmp/test1/paltest_strncmp_test1
-c_runtime/strncpy/test1/paltest_strncpy_test1
-c_runtime/strpbrk/test1/paltest_strpbrk_test1
-c_runtime/strrchr/test1/paltest_strrchr_test1
-c_runtime/strstr/test1/paltest_strstr_test1
-c_runtime/tolower/test1/paltest_tolower_test1
-c_runtime/toupper/test1/paltest_toupper_test1
-c_runtime/towlower/test1/paltest_towlower_test1
-c_runtime/towupper/test1/paltest_towupper_test1
 c_runtime/wcscat/test1/paltest_wcscat_test1
 c_runtime/wcschr/test1/paltest_wcschr_test1
 c_runtime/wcscmp/test1/paltest_wcscmp_test1
@@ -64,9 +32,6 @@ c_runtime/wcstoul/test3/paltest_wcstoul_test3
 c_runtime/wcstoul/test4/paltest_wcstoul_test4
 c_runtime/wcstoul/test5/paltest_wcstoul_test5
 c_runtime/wcstoul/test6/paltest_wcstoul_test6
-c_runtime/_alloca/test1/paltest_alloca_test1
-c_runtime/_rotl/test1/paltest_rotl_test1
-c_runtime/_rotr/test1/paltest_rotr_test1
 c_runtime/_vsnprintf_s/test1/paltest_vsnprintf_test1
 c_runtime/_vsnprintf_s/test10/paltest_vsnprintf_test10
 c_runtime/_vsnprintf_s/test11/paltest_vsnprintf_test11
@@ -101,24 +66,10 @@ filemapping_memmgt/GetProcAddress/test1/paltest_getprocaddress_test1
 filemapping_memmgt/GetProcAddress/test2/paltest_getprocaddress_test2
 filemapping_memmgt/ProbeMemory/ProbeMemory_neg1/paltest_probememory_probememory_neg1
 filemapping_memmgt/ProbeMemory/test1/paltest_probememory_test1
-loader/LoadLibraryA/test1/paltest_loadlibrarya_test1
-loader/LoadLibraryA/test2/paltest_loadlibrarya_test2
-loader/LoadLibraryA/test3/paltest_loadlibrarya_test3
-loader/LoadLibraryA/test5/paltest_loadlibrarya_test5
-loader/LoadLibraryA/test7/paltest_loadlibrarya_test7
 loader/LoadLibraryW/test1/paltest_loadlibraryw_test1
 loader/LoadLibraryW/test2/paltest_loadlibraryw_test2
 loader/LoadLibraryW/test3/paltest_loadlibraryw_test3
 loader/LoadLibraryW/test5/paltest_loadlibraryw_test5
-locale_info/MultiByteToWideChar/test1/paltest_multibytetowidechar_test1
-locale_info/MultiByteToWideChar/test2/paltest_multibytetowidechar_test2
-locale_info/MultiByteToWideChar/test3/paltest_multibytetowidechar_test3
-locale_info/MultiByteToWideChar/test4/paltest_multibytetowidechar_test4
-locale_info/WideCharToMultiByte/test1/paltest_widechartomultibyte_test1
-locale_info/WideCharToMultiByte/test2/paltest_widechartomultibyte_test2
-locale_info/WideCharToMultiByte/test3/paltest_widechartomultibyte_test3
-locale_info/WideCharToMultiByte/test4/paltest_widechartomultibyte_test4
-locale_info/WideCharToMultiByte/test5/paltest_widechartomultibyte_test5
 miscellaneous/CloseHandle/test2/paltest_closehandle_test2
 miscellaneous/FlushInstructionCache/test1/paltest_flushinstructioncache_test1
 miscellaneous/FormatMessageW/test1/paltest_formatmessagew_test1
@@ -172,8 +123,6 @@ miscellaneous/SetEnvironmentVariableW/test4/paltest_setenvironmentvariablew_test
 miscellaneous/SetLastError/test1/paltest_setlasterror_test1
 pal_specific/PAL_Initialize_Terminate/test1/paltest_pal_initialize_terminate_test1
 pal_specific/PAL_Initialize_Terminate/test2/paltest_pal_initialize_terminate_test2
-pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test1/paltest_pal_registerlibraryw_unregisterlibraryw_test1
-pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test2_neg/paltest_reg_unreg_libraryw_neg
 samples/test1/paltest_samples_test1
 samples/test2/paltest_samples_test2
 threading/CreateThread/test1/paltest_createthread_test1
@@ -194,8 +143,6 @@ threading/GetCurrentThreadId/test1/paltest_getcurrentthreadid_test1
 threading/QueryThreadCycleTime/test1/paltest_querythreadcycletime_test1
 threading/ResumeThread/test1/paltest_resumethread_test1
 threading/RuntimeEvent/test1/paltest_runtimeevent_test1
-threading/Sleep/test1/paltest_sleep_test1
-threading/Sleep/test2/paltest_sleep_test2
 threading/SwitchToThread/test1/paltest_switchtothread_test1
 threading/TerminateProcess/test1/paltest_terminateprocess_test1
 threading/ThreadPriority/test1/paltest_threadpriority_test1
diff --git a/src/coreclr/pal/tests/palsuite/compileDisabledTests.txt b/src/coreclr/pal/tests/palsuite/compileDisabledTests.txt
index 6f826fc83fa0c8..3d73dd7a245092 100644
--- a/src/coreclr/pal/tests/palsuite/compileDisabledTests.txt
+++ b/src/coreclr/pal/tests/palsuite/compileDisabledTests.txt
@@ -4,7 +4,6 @@ composite/synchronization/criticalsection/paltest_synchronization_criticalsectio
 composite/synchronization/nativecriticalsection/paltest_synchronization_nativecriticalsection
 composite/synchronization/nativecs_interlocked/paltest_synchronization_nativecs_interlocked
 composite/wfmo/paltest_composite_wfmo
-c_runtime/iswprint/test1/paltest_iswprint_test1
 c_runtime/vprintf/test1/paltest_vprintf_test1
 debug_api/DebugBreak/test1/paltest_debugbreak_test1
 exception_handling/pal_except/test1/paltest_pal_except_test1
@@ -27,17 +26,6 @@ exception_handling/PAL_TRY_EXCEPT_EX/test1/paltest_pal_try_except_ex_test1
 exception_handling/PAL_TRY_EXCEPT_EX/test2/paltest_pal_try_except_ex_test2
 exception_handling/PAL_TRY_EXCEPT_EX/test3/paltest_pal_try_except_ex_test3
 exception_handling/PAL_TRY_LEAVE_FINALLY/test1/paltest_pal_try_leave_finally_test1
-loader/LoadLibraryA/test6/paltest_loadlibrarya_test6
-loader/LoadLibraryA/test8/paltest_loadlibrarya_test8
-locale_info/CompareStringA/test1/paltest_comparestringa_test1
-locale_info/CompareStringW/test1/paltest_comparestringw_test1
-locale_info/GetLocaleInfoW/test1/paltest_getlocaleinfow_test1
-locale_info/GetLocaleInfoW/test2/paltest_getlocaleinfow_test2
-miscellaneous/IsBadCodePtr/test1/paltest_isbadcodeptr_test1
-miscellaneous/IsBadReadPtr/test1/paltest_isbadreadptr_test1
-miscellaneous/IsBadWritePtr/test1/paltest_isbadwriteptr_test1
-miscellaneous/IsBadWritePtr/test2/paltest_isbadwriteptr_test2
-miscellaneous/IsBadWritePtr/test3/paltest_isbadwriteptr_test3
 pal_specific/PAL_get_stderr/test1/paltest_pal_get_stderr_test1
 pal_specific/PAL_get_stdin/test1/paltest_pal_get_stdin_test1
 pal_specific/PAL_get_stdout/test1/paltest_pal_get_stdout_test1
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test1/LoadLibraryA.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test1/LoadLibraryA.cpp
deleted file mode 100644
index 53c564fad8bbc8..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test1/LoadLibraryA.cpp
+++ /dev/null
@@ -1,52 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source:  loadlibrarya.c
-**
-** Purpose: Positive test the LoadLibrary API.
-**          Call LoadLibrary to map a module into the calling
-**          process address space(DLL file)
-**
-**
-**============================================================*/
-#include <palsuite.h>
-
-/* SHLEXT is defined only for Unix variants */
-
-#if defined(SHLEXT)
-#define ModuleName    "librotor_pal"SHLEXT
-#else
-#define ModuleName    "rotor_pal.dll"
-#endif
-
-PALTEST(loader_LoadLibraryA_test1_paltest_loadlibrarya_test1, "loader/LoadLibraryA/test1/paltest_loadlibrarya_test1")
-{
-    HMODULE ModuleHandle;
-    int err;
-
-    /* Initialize the PAL environment */
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        ExitProcess(FAIL);
-    }
-
-    /* load a module */
-    ModuleHandle = LoadLibraryExA(ModuleName, NULL, 0);
-    if(!ModuleHandle)
-    {
-        Fail("Failed to call LoadLibrary API!\n");
-    }
-
-    /* decrement the reference count of the loaded dll */
-    err = FreeLibrary(ModuleHandle);
-    if(0 == err)
-    {
-        Fail("\nFailed to all FreeLibrary API!\n");
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test2/LoadLibraryA.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test2/LoadLibraryA.cpp
deleted file mode 100644
index ca8e52c408cc13..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test2/LoadLibraryA.cpp
+++ /dev/null
@@ -1,51 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source: loadlibrarya.c
-**
-** Purpose: Negative test the LoadLibraryA API.
-**          Call LoadLibraryA with a not exist module Name
-**
-**
-**============================================================*/
-#include <palsuite.h>
-
-PALTEST(loader_LoadLibraryA_test2_paltest_loadlibrarya_test2, "loader/LoadLibraryA/test2/paltest_loadlibrarya_test2")
-{
-    HMODULE ModuleHandle;
-    int err;
-    const char *pModuleName = "Not-exist-module-name";
-
-    /* Initialize the PAL environment */
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        return FAIL;
-    }
-
-    /*try to load a not exist module */
-    ModuleHandle = LoadLibraryExA(pModuleName, NULL, 0);
-    if(NULL != ModuleHandle)
-    {
-        Trace("Failed to call LoadLibraryExA with a not exist mudule name, "
-            "a NULL module handle is expected, but no NULL module handle "
-            "is returned, error code=%u\n", GetLastError());
-
-        /* decrement the reference count of the loaded module */
-        err = FreeLibrary(ModuleHandle);
-        if(0 == err)
-        {
-            Trace("\nFailed to all FreeLibrary API to decrement "
-                    "the reference count of the loaded module, "
-                    "error code = %u\n", GetLastError());
-
-        }
-
-        Fail("");
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test3/loadlibrarya.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test3/loadlibrarya.cpp
deleted file mode 100644
index cbb41f3457baef..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test3/loadlibrarya.cpp
+++ /dev/null
@@ -1,39 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source: loadlibrarya.c
-**
-** Purpose: Negative test the LoadLibrary API with NULL module
-**          name.
-**
-**
-**============================================================*/
-#include <palsuite.h>
-
-PALTEST(loader_LoadLibraryA_test3_paltest_loadlibrarya_test3, "loader/LoadLibraryA/test3/paltest_loadlibrarya_test3")
-{
-    HMODULE ModuleHandle;
-    int err;
-
-    /*Initialize the PAL environment*/
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        return FAIL;
-    }
-
-    /*load a module by passing a NULL module name*/
-    ModuleHandle = LoadLibraryExA(NULL, NULL, 0);
-    if(NULL != ModuleHandle)
-    {
-        Fail("\nFailed to call LoadLibraryExA API for a negative test, "
-            "call LoadLibraryExA with NULL moudle name, a NULL module "
-            "handle is expected, but no NULL module handle is returned, "
-            "error code =%u\n", GetLastError());
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test5/loadlibrarya.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test5/loadlibrarya.cpp
deleted file mode 100644
index b8f609001f2424..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test5/loadlibrarya.cpp
+++ /dev/null
@@ -1,66 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source: loadlibrarya.c
-**
-** Purpose: Negative test the LoadLibraryA API.
-**          Call LoadLibraryA by passing a module name
-**          without extension but with a trailing dot.
-**
-**
-**============================================================*/
-#include <palsuite.h>
-
-PALTEST(loader_LoadLibraryA_test5_paltest_loadlibrarya_test5, "loader/LoadLibraryA/test5/paltest_loadlibrarya_test5")
-{
-    HMODULE ModuleHandle;
-    char ModuleName[_MAX_FNAME];
-    int err;
-
-    /* Initialize the PAL environment */
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        return FAIL;
-    }
-
-    memset(ModuleName, 0, _MAX_FNAME);
-
-    /*Module name without extension but with a trailing dot*/
-#if WIN32
-    sprintf_s(ModuleName, ARRAY_SIZE(ModuleName), "%s", "rotor_pal.");
-#else
-    /* Under FreeBSD */
-    sprintf_s(ModuleName, ARRAY_SIZE(ModuleName), "%s", "librotor_pal.");
-#endif
-
-    /* load a module which does not have the file extension,
-     * but has a trailing dot
-    */
-    ModuleHandle = LoadLibraryExA(ModuleName, NULL, 0);
-    if(NULL != ModuleHandle)
-    {
-        Trace("Failed to call LoadLibraryExA API for a negative test "
-            "call LoadLibraryExA with module name which does not have "
-            "extension except a trailing dot, a NULL module handle is"
-            "expected, but no NULL module handle is returned, "
-             "error code = %u\n", GetLastError());
-
-
-        /* decrement the reference count of the loaded dll */
-        err = FreeLibrary(ModuleHandle);
-        if(0 == err)
-        {
-            Trace("\nFailed to call FreeLibrary API, "
-                "error code = %u\n", GetLastError());
-        }
-
-        Fail("");
-    }
-
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test6/dlltest.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test6/dlltest.cpp
deleted file mode 100644
index 6e2cdeb7c9a715..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test6/dlltest.cpp
+++ /dev/null
@@ -1,71 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================================
-**
-** Source:    dllmain.c
-**
-** Purpose: Test to ensure DllMain() is called with DLL_THREAD_DETACH
-**          only the initial time that the library is loaded.
-** 
-** Depends: None
-** 
-
-**
-**===========================================================================*/
-
-#include <palsuite.h>
-
-/* count of the number of times DllMain()
- * was called with THREAD_ATTACH.
- */
-static int g_attachCount = 0;
-
-/* standard DllMain() */
-BOOL PALAPI DllMain(HINSTANCE hinstDLL, DWORD reason, LPVOID lpvReserved)
-{
-    switch( reason )
-    {
-        case DLL_PROCESS_ATTACH:
-        {
-            g_attachCount++;
-            break;
-        }
-    
-        case DLL_PROCESS_DETACH:
-        {
-            break;
-        }
-        
-        case DLL_THREAD_ATTACH:
-        {
-            break;
-        }
-    
-        case DLL_THREAD_DETACH:
-        {
-            break;
-        }
-    }
-
-    return TRUE;
-}
-
-#if _WIN32
-BOOL PALAPI _DllMainCRTStartup(HINSTANCE hinstDLL, DWORD reason, LPVOID lpvReserved)
-{
-    return DllMain(hinstDLL, reason, lpvReserved);
-}
-#endif
-
-
-
-/* function to return the current attach count */
-#if _WIN32
-__declspec(dllexport)
-#endif
-int PALAPI GetAttachCount( void )
-{
-    return g_attachCount;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test6/loadlibrarya.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test6/loadlibrarya.cpp
deleted file mode 100644
index e8db6ca4bccc7c..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test6/loadlibrarya.cpp
+++ /dev/null
@@ -1,169 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source:  loadlibrary.c (test 6)
-**
-** Purpose: Positive test the LoadLibrary API. Test will verify
-**          that it is unable to load the library twice. Once by
-**          using the full path name and secondly by using the
-**          short name.
-**
-
-**
-**============================================================*/
-#include <palsuite.h>
-
-/*Define platform specific information*/
-#if defined(SHLEXT)
-#define LibraryName    "dlltest"SHLEXT
-#define GETATTACHCOUNTNAME "GetAttachCount"
-#else
-typedef int (*dllfunct)();
-#define LibraryName    "dlltest.dll"
-#define GETATTACHCOUNTNAME "_GetAttachCount@0"
-#endif
-
-/* Helper function to test the loaded library.
- */
-BOOL PALAPI TestDll(HMODULE hLib)
-{
-    int     RetVal;
-    char    FunctName[] = GETATTACHCOUNTNAME;
-    FARPROC DllFunc;
-
-    /* Access a function from the loaded library.
-     */
-    DllFunc = GetProcAddress(hLib, FunctName);
-    if(DllFunc == NULL)
-    {
-        Trace("ERROR: Unable to load function \"%s\" from library \"%s\"\n",
-              FunctName,
-              LibraryName);
-        return (FALSE);
-    }
-
-    /* Verify that the DLL_PROCESS_ATTACH is only
-     * accessed once.*/
-    RetVal = DllFunc();
-    if (RetVal != 1)
-    {
-        Trace("ERROR: Unable to receive correct information from DLL! "
-              ":expected \"1\", returned \"%d\"\n",
-              RetVal);
-        return (FALSE);
-    }
-
-    return (TRUE);
-}
-
-PALTEST(loader_LoadLibraryA_test6_paltest_loadlibrarya_test6, "loader/LoadLibraryA/test6/paltest_loadlibrarya_test6")
-{
-    HANDLE hFullLib;
-    HANDLE hShortLib;
-    int    iRetVal  = FAIL;
-    char   fullPath[_MAX_DIR];
-	char drive[_MAX_DRIVE];
-    char dir[_MAX_DIR];
-    char fname[_MAX_FNAME];
-    char ext[_MAX_EXT];
-
-
-
-    /* Initialize the PAL. */
-    if ((PAL_Initialize(argc, argv)) != 0)
-    {
-        return (FAIL);
-    }
-
-    /* Initialize the buffer.
-     */
-    memset(fullPath, 0, _MAX_DIR);
-
-    /* Get the full path to the library (DLL).
-     */
-
-	if (NULL != realpath(argv[0],fullpath)) {
-
-	 _splitpath(fullPath,drive,dir,fname,ext);
-	 _makepath(fullPath,drive,dir,LibraryName,"");
-
-
-	} else {
-		Fail("ERROR: conversion from relative path \" %s \" to absolute path failed. realpath returned NULL\n",argv[0]);
-	}
-
-    /* Call Load library with the short name of
-     * the dll.
-     */
-    hShortLib = LoadLibrary(LibraryName);
-    if(hShortLib == NULL)
-    {
-        Fail("ERROR:%u:Unable to load library %s\n",
-             GetLastError(),
-             LibraryName);
-    }
-
-    /* Test the loaded library.
-     */
-    if (!TestDll(hShortLib))
-    {
-        iRetVal = FAIL;
-        goto cleanUpOne;
-    }
-
-    /* Call Load library with the full name of
-     * the dll.
-     */
-    hFullLib = LoadLibrary(fullPath);
-    if(hFullLib == NULL)
-    {
-        Trace("ERROR:%u:Unable to load library %s\n",
-              GetLastError(),
-              fullPath);
-        iRetVal = FAIL;
-        goto cleanUpTwo;
-    }
-
-    /* Test the loaded library.
-     */
-    if (!TestDll(hFullLib))
-    {
-        iRetVal = FAIL;
-        goto cleanUpTwo;
-    }
-
-    /* Test Succeeded.
-     */
-    iRetVal = PASS;
-
-cleanUpTwo:
-
-    /* Call the FreeLibrary API.
-     */
-    if (!FreeLibrary(hFullLib))
-    {
-        Trace("ERROR:%u: Unable to free library \"%s\"\n",
-              GetLastError(),
-              fullPath);
-        iRetVal = FAIL;
-    }
-
-cleanUpOne:
-
-    /* Call the FreeLibrary API.
-     */
-    if (!FreeLibrary(hShortLib))
-    {
-        Trace("ERROR:%u: Unable to free library \"%s\"\n",
-              GetLastError(),
-              LibraryName);
-        iRetVal = FAIL;
-    }
-
-    /* Terminate the PAL.
-     */
-    PAL_TerminateEx(iRetVal);
-    return iRetVal;
-}
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test7/LoadLibraryA.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test7/LoadLibraryA.cpp
deleted file mode 100644
index 1ad2a754fd60e7..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test7/LoadLibraryA.cpp
+++ /dev/null
@@ -1,82 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source:  loadlibrarya.c
-**
-** Purpose: Positive test the LoadLibrary API by calling it multiple times.
-**          Call LoadLibrary to map a module into the calling
-**          process address space(DLL file)
-**
-**
-**============================================================*/
-#include <palsuite.h>
-
-/* SHLEXT is defined only for Unix variants */
-
-#if defined(SHLEXT)
-#define ModuleName    "librotor_pal"SHLEXT
-#else
-#define ModuleName    "rotor_pal.dll"
-#endif
-
-PALTEST(loader_LoadLibraryA_test7_paltest_loadlibrarya_test7, "loader/LoadLibraryA/test7/paltest_loadlibrarya_test7")
-{
-    HMODULE ModuleHandle;
-    HMODULE ReturnHandle;
-    int err;
-
-    /* Initialize the PAL environment */
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        ExitProcess(FAIL);
-    }
-
-    /* load a module */
-    ModuleHandle = LoadLibraryExA(ModuleName, NULL, 0);
-    if(!ModuleHandle)
-    {
-        Fail("Error[%u]:Failed to call LoadLibrary API!\n", GetLastError());
-    }
-
-    /* Call LoadLibrary again, should return same handle as returned for first time */
-    ReturnHandle = LoadLibraryExA(ModuleName, NULL, 0);
-    if(!ReturnHandle)
-    {
-        Fail("Error[%u]:Failed to call LoadLibrary API second time!\n", GetLastError());
-    }
-
-    if(ModuleHandle != ReturnHandle)
-    {
-        Fail("Error[%u]:Failed to return the same handle while calling LoadLibrary API twice!\n", GetLastError());
-    }
-
-    Trace("Value of handle ModuleHandle[%x], ReturnHandle[%x]\n", ModuleHandle, ReturnHandle);
-	/* decrement the reference count of the loaded dll */
-    err = FreeLibrary(ModuleHandle);
-
-    if(0 == err)
-    {
-		Fail("Error[%u]:Failed to FreeLibrary API!\n", GetLastError());
-    }
-
-	/* Try Freeing a library again, should not fail */
-	err = FreeLibrary(ReturnHandle);
-
-    if(0 == err)
-    {
-		Fail("Error[%u][%d]: Was not successful in freeing a Library twice using FreeLibrary!\n", GetLastError(), err);
-    }
-
-	/* Try Freeing a library again, should fail */
-	err = FreeLibrary(ReturnHandle);
-
-    if(1 != err)
-    {
-		Fail("Error[%u][%d]: Was successful in freeing a Library thrice using FreeLibrary!\n", GetLastError(), err);
-    }
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test8/dlltest.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test8/dlltest.cpp
deleted file mode 100644
index 6e2cdeb7c9a715..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test8/dlltest.cpp
+++ /dev/null
@@ -1,71 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================================
-**
-** Source:    dllmain.c
-**
-** Purpose: Test to ensure DllMain() is called with DLL_THREAD_DETACH
-**          only the initial time that the library is loaded.
-** 
-** Depends: None
-** 
-
-**
-**===========================================================================*/
-
-#include <palsuite.h>
-
-/* count of the number of times DllMain()
- * was called with THREAD_ATTACH.
- */
-static int g_attachCount = 0;
-
-/* standard DllMain() */
-BOOL PALAPI DllMain(HINSTANCE hinstDLL, DWORD reason, LPVOID lpvReserved)
-{
-    switch( reason )
-    {
-        case DLL_PROCESS_ATTACH:
-        {
-            g_attachCount++;
-            break;
-        }
-    
-        case DLL_PROCESS_DETACH:
-        {
-            break;
-        }
-        
-        case DLL_THREAD_ATTACH:
-        {
-            break;
-        }
-    
-        case DLL_THREAD_DETACH:
-        {
-            break;
-        }
-    }
-
-    return TRUE;
-}
-
-#if _WIN32
-BOOL PALAPI _DllMainCRTStartup(HINSTANCE hinstDLL, DWORD reason, LPVOID lpvReserved)
-{
-    return DllMain(hinstDLL, reason, lpvReserved);
-}
-#endif
-
-
-
-/* function to return the current attach count */
-#if _WIN32
-__declspec(dllexport)
-#endif
-int PALAPI GetAttachCount( void )
-{
-    return g_attachCount;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test8/loadlibrarya.cpp b/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test8/loadlibrarya.cpp
deleted file mode 100644
index 3276bc5a703808..00000000000000
--- a/src/coreclr/pal/tests/palsuite/loader/LoadLibraryA/test8/loadlibrarya.cpp
+++ /dev/null
@@ -1,231 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source:  loadlibrary.c (test 8)
-**
-** Purpose: Positive test the LoadLibrary API. Test will verify
-**          that it is unable to load the library twice. Once by
-**          using the full path name and secondly by using the
-**          short name.
-**
-
-**
-**============================================================*/
-#include <palsuite.h>
-
-/*Define platform specific information*/
-#if defined(SHLEXT)
-#define LibraryName    "dlltest"SHLEXT
-#define GETATTACHCOUNTNAME "GetAttachCount"
-#else
-typedef int (*dllfunct)();
-#define LibraryName    "dlltest.dll"
-#define GETATTACHCOUNTNAME "_GetAttachCount@0"
-#endif
-
-/* Helper function to test the loaded library.
- */
-BOOL PALAPI TestDll(HMODULE hLib)
-{
-    int     RetVal;
-    char    FunctName[] = GETATTACHCOUNTNAME;
-    FARPROC DllFunc;
-
-    /* Access a function from the loaded library.
-     */
-    DllFunc = GetProcAddress(hLib, FunctName);
-    if(DllFunc == NULL)
-    {
-        Trace("ERROR: Unable to load function \"%s\" from library \"%s\"\n",
-              FunctName,
-              LibraryName);
-        return (FALSE);
-    }
-
-    /* Verify that the DLL_PROCESS_ATTACH is only
-     * accessed once.*/
-    RetVal = DllFunc();
-    if (RetVal != 1)
-    {
-        Trace("ERROR: Unable to receive correct information from DLL! "
-              ":expected \"1\", returned \"%d\"\n",
-              RetVal);
-        return (FALSE);
-    }
-
-    return (TRUE);
-}
-
-PALTEST(loader_LoadLibraryA_test8_paltest_loadlibrarya_test8, "loader/LoadLibraryA/test8/paltest_loadlibrarya_test8")
-{
-    HANDLE hFullLib;
-    HANDLE hShortLib;
-    HANDLE hRelLib;
-
-    int    iRetVal  = FAIL;
-    char   fullPath[_MAX_DIR];
-    char drive[_MAX_DRIVE];
-    char dir[_MAX_DIR];
-    char relTestDir[_MAX_DIR];
-    char fname[_MAX_FNAME];
-    char ext[_MAX_EXT];
-
-    BOOL bRc = FALSE;
-    char   relLibPath[_MAX_DIR];
-
-
-    /* Initialize the PAL. */
-    if ((PAL_Initialize(argc, argv)) != 0)
-    {
-        return (FAIL);
-    }
-
-    /* Initialize the buffer.
-     */
-    memset(fullPath, 0, _MAX_DIR);
-
-    /* Get the full path to the library (DLL).
-     */
-
-       if (NULL != realpath(argv[0],fullpath)) {
-
-	 _splitpath(fullPath,drive,dir,fname,ext);
-	 _makepath(fullPath,drive,dir,LibraryName,"");
-
-
-	} else {
-		Fail("ERROR: conversion from relative path \" %s \" to absolute path failed. realpath returned NULL\n",argv[0]);
-	}
-
-       /* Get relative path to the library
-	*/
-       _splitpath(argv[0], drive, relTestDir, fname, ext);
-       _makepath(relLibPath,drive,relTestDir,LibraryName,"");
-
-
-    /* Call Load library with the short name of
-     * the dll.
-     */
-    hShortLib = LoadLibrary(LibraryName);
-    if(hShortLib == NULL)
-    {
-        Fail("ERROR:%u:Short:Unable to load library %s\n",
-             GetLastError(),
-             LibraryName);
-    }
-
-    /* Test the loaded library.
-     */
-    if (!TestDll(hShortLib))
-    {
-        iRetVal = FAIL;
-        goto cleanUpOne;
-    }
-
-    /* Call Load library with the full name of
-     * the dll.
-     */
-    hFullLib = LoadLibrary(fullPath);
-    if(hFullLib == NULL)
-    {
-        Trace("ERROR:%u:Full:Unable to load library %s\n",
-              GetLastError(),
-              fullPath);
-        iRetVal = FAIL;
-        goto cleanUpTwo;
-    }
-
-    /* Test the loaded library.
-     */
-    if (!TestDll(hFullLib))
-    {
-        iRetVal = FAIL;
-        goto cleanUpTwo;
-    }
-
-    /*
-    ** Call the load library with the relative path
-    ** wrt to the directory ./testloadlibrary/..
-    ** since we don't want to make any assumptions
-    ** regarding the type of build
-    */
-    hRelLib = LoadLibrary(relLibPath);
-    if(hRelLib == NULL)
-    {
-        Trace("ERROR:%u:Rel:Unable to load library at %s\n",
-              GetLastError(), relLibPath);
-        iRetVal = FAIL;
-        goto cleanUpTwo;
-    }
-
-    /* Test the loaded library.
-     */
-    if (!TestDll(hRelLib))
-    {
-        iRetVal = FAIL;
-        goto cleanUpThree;
-    }
-
-   if( hRelLib != hFullLib )
-   {
-        Trace("Relative and Absolute Paths to libraries don't have same handle\n");
-            iRetVal = FAIL;
-            goto cleanUpThree;
-   }
-
-   if( hRelLib != hShortLib )
-   {
-        Trace("Relative and Short Paths to libraries don't have same handle\n");
-            iRetVal = FAIL;
-            goto cleanUpThree;
-   }
-
-
-   /* Test Succeeded.
-     */
-    iRetVal = PASS;
-
-cleanUpThree:
-
-    /* Call the FreeLibrary API.
-     */
-
-    if (!FreeLibrary(hRelLib))
-    {
-        Trace("ERROR:%u: Unable to free library \"%s\"\n",
-              GetLastError(),
-              relLibPath);
-        iRetVal = FAIL;
-    }
-
-cleanUpTwo:
-
-    /* Call the FreeLibrary API.
-     */
-    if (!FreeLibrary(hFullLib))
-    {
-        Trace("ERROR:%u: Unable to free library \"%s\"\n",
-              GetLastError(),
-              fullPath);
-        iRetVal = FAIL;
-    }
-
-cleanUpOne:
-
-    /* Call the FreeLibrary API.
-     */
-    if (!FreeLibrary(hShortLib))
-    {
-        Trace("ERROR:%u: Unable to free library \"%s\"\n",
-              GetLastError(),
-              LibraryName);
-        iRetVal = FAIL;
-    }
-
-    /* Terminate the PAL.
-     */
-    PAL_TerminateEx(iRetVal);
-    return iRetVal;
-}
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/CompareStringA/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/locale_info/CompareStringA/test1/test1.cpp
deleted file mode 100644
index 91d4ae9da3ca74..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/CompareStringA/test1/test1.cpp
+++ /dev/null
@@ -1,98 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test1.c
-**
-** Purpose: Tests that CompareStringA returns the correct value and can handle
-**          invalid parameters.
-**
-**
-**==========================================================================*/
-
-#define CSTR_LESS_THAN 1
-#define CSTR_EQUAL 2
-#define CSTR_GREATER_THAN 3
-
-#include <palsuite.h>
-
-PALTEST(locale_info_CompareStringA_test1_paltest_comparestringa_test1, "locale_info/CompareStringA/test1/paltest_comparestringa_test1")
-{    
-    char str1[] = {'f','o','o',0};
-    char str2[] = {'f','o','o','x',0};
-    char str3[] = {'f','O','o',0};
-    int flags = NORM_IGNORECASE | NORM_IGNOREWIDTH;
-    int ret;
-
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    ret = CompareStringA(0x0409, flags, str1, -1, str2, -1);
-    if (ret != CSTR_LESS_THAN)
-    {
-        Fail("CompareStringA with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_LESS_THAN!\n", str1, -1, str2, -1);
-    }
-
-    ret = CompareStringA(0x0409, flags, str1, -1, str2, 3);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringA with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str1, -1, str2, 3);
-    }
-
-    ret = CompareStringA(0x0409, flags, str2, -1, str1, -1);
-    if (ret != CSTR_GREATER_THAN)
-    {
-        Fail("CompareStringA with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_GREATER_THAN!\n", str2, -1, str1, -1);
-    }
-
-    ret = CompareStringA(0x0409, flags, str1, -1, str3, -1);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringA with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str1, -1, str3, -1);
-    }
-
-    ret = CompareStringA(0x0409, flags, str3, -1, str1, -1);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringA with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str3, -1, str1, -1);
-    }
-
-    ret = CompareStringA(0x0409, flags, str3, -1, str1, -1);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringA with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str3, -1, str1, -1);
-    }
-
-    ret = CompareStringA(0x0409, flags, str1, 0, str3, -1);
-    if (ret != CSTR_LESS_THAN)
-    {
-        Fail("CompareStringA with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_GREATER_THAN!\n", str1, 0, str3, -1);
-    }
-
-    
-    ret = CompareStringA(0x0409, flags, NULL, -1, str3, -1);
-    if (ret != 0)
-    {
-        Fail("CompareStringA should have returned 0, got %d!\n", ret);
-    }
-    if (GetLastError() != ERROR_INVALID_PARAMETER)
-    {
-        Fail("CompareStringA should have set the last error to "
-            "ERROR_INVALID_PARAMETER!\n");
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/CompareStringW/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/locale_info/CompareStringW/test1/test1.cpp
deleted file mode 100644
index d15094609a9959..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/CompareStringW/test1/test1.cpp
+++ /dev/null
@@ -1,98 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test1.c
-**
-** Purpose: Tests that CompareStringW returns the correct value and can handle
-**          invalid parameters.
-**
-**
-**==========================================================================*/
-
-#define CSTR_LESS_THAN 1
-#define CSTR_EQUAL 2
-#define CSTR_GREATER_THAN 3
-
-#include <palsuite.h>
-
-PALTEST(locale_info_CompareStringW_test1_paltest_comparestringw_test1, "locale_info/CompareStringW/test1/paltest_comparestringw_test1")
-{    
-    WCHAR str1[] = {'f','o','o',0};
-    WCHAR str2[] = {'f','o','o','x',0};
-    WCHAR str3[] = {'f','O','o',0};
-    int flags = NORM_IGNORECASE | NORM_IGNOREWIDTH;
-    int ret;
-
-    if (0 != PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    ret = CompareStringW(0x0409, flags, str1, -1, str2, -1);
-    if (ret != CSTR_LESS_THAN)
-    {
-        Fail("CompareStringW with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_LESS_THAN!\n", str1, -1, str2, -1);
-    }
-
-    ret = CompareStringW(0x0409, flags, str1, -1, str2, 3);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringW with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str1, -1, str2, 3);
-    }
-
-    ret = CompareStringW(0x0409, flags, str2, -1, str1, -1);
-    if (ret != CSTR_GREATER_THAN)
-    {
-        Fail("CompareStringW with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_GREATER_THAN!\n", str2, -1, str1, -1);
-    }
-
-    ret = CompareStringW(0x0409, flags, str1, -1, str3, -1);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringW with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str1, -1, str3, -1);
-    }
-
-    ret = CompareStringW(0x0409, flags, str3, -1, str1, -1);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringW with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str3, -1, str1, -1);
-    }
-
-    ret = CompareStringW(0x0409, flags, str3, -1, str1, -1);
-    if (ret != CSTR_EQUAL)
-    {
-        Fail("CompareStringW with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_EQUAL!\n", str3, -1, str1, -1);
-    }
-
-    ret = CompareStringW(0x0409, flags, str1, 0, str3, -1);
-    if (ret != CSTR_LESS_THAN)
-    {
-        Fail("CompareStringW with \"%S\" (%d) and \"%S\" (%d) did not return "
-            "CSTR_GREATER_THAN!\n", str1, 0, str3, -1);
-    }
-
-    
-    ret = CompareStringW(0x0409, flags, NULL, -1, str3, -1);
-    if (ret != 0)
-    {
-        Fail("CompareStringW should have returned 0, got %d!\n", ret);
-    }
-    if (GetLastError() != ERROR_INVALID_PARAMETER)
-    {
-        Fail("CompareStringW should have set the last error to "
-            "ERROR_INVALID_PARAMETER!\n");
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/GetLocaleInfoW/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/locale_info/GetLocaleInfoW/test1/test1.cpp
deleted file mode 100644
index ea9cbb331c101b..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/GetLocaleInfoW/test1/test1.cpp
+++ /dev/null
@@ -1,86 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test1.c
-**
-** Purpose: Tests that GetLocaleInfoW gives the correction information for
-**          LOCALE_NEUTRAL.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-int Types[] = { LOCALE_SDECIMAL, LOCALE_STHOUSAND, LOCALE_ILZERO,
-    LOCALE_SCURRENCY, LOCALE_SMONDECIMALSEP, LOCALE_SMONTHOUSANDSEP };
-
-char *TypeStrings[] = { "LOCALE_SDECIMAL", "LOCALE_STHOUSAND", "LOCALE_ILZERO",
-    "LOCALE_SCURRENCY", "LOCALE_SMONDECIMALSEP", "LOCALE_SMONTHOUSANDSEP" };
-
-typedef WCHAR InfoStrings[ARRAY_SIZE(Types)][4];
-
-typedef struct
-{
-    LCID lcid;
-    InfoStrings Strings;
-} LocalInfoType;
-
-LocalInfoType Locales[] =
-{
-    {LOCALE_NEUTRAL,
-        {{'.',0}, {',',0}, {'1',0}, {'$',0}, {'.',0}, {',',0}}},
-};
-
-int NumLocales = sizeof(Locales) / sizeof(Locales[0]);
-
-
-PALTEST(locale_info_GetLocaleInfoW_test1_paltest_getlocaleinfow_test1, "locale_info/GetLocaleInfoW/test1/paltest_getlocaleinfow_test1")
-{
-    WCHAR buffer[256] = { 0 };
-    int ret;
-    int i,j;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    for (i=0; i<NumLocales; i++)
-    {
-        for (j=0; j < ARRAY_SIZE(Types); j++)
-        {
-            ret = GetLocaleInfoW(Locales[i].lcid, Types[j], buffer, 256);
-
-            if (ret == 0)
-            {
-                Fail("GetLocaleInfoW returned an unexpected error!\n");
-            }
-
-
-            if (wcscmp(buffer, Locales[i].Strings[j]) != 0)
-            {
-
-                Fail("GetLocaleInfoW gave incorrect result for %s, "
-                    "locale %#x:\nExpected \"%S\", got \"%S\"!\n", TypeStrings[j],
-                    Locales[i].lcid, Locales[i].Strings[j], buffer);
-
-            }
-
-            if (ret != wcslen(Locales[i].Strings[j]) + 1)
-            {
-                Fail("GetLocaleInfoW returned incorrect value for %s, "
-                    "locale %#x:\nExpected %d, got %d!\n", TypeStrings[j],
-                    Locales[i].lcid, wcslen(Locales[i].Strings[j])+1, ret);
-            }
-        }
-    }
-
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/GetLocaleInfoW/test2/test2.cpp b/src/coreclr/pal/tests/palsuite/locale_info/GetLocaleInfoW/test2/test2.cpp
deleted file mode 100644
index 5a5a3aa21b3d28..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/GetLocaleInfoW/test2/test2.cpp
+++ /dev/null
@@ -1,50 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test2.c
-**
-** Purpose: Tests that GetLocaleInfoW will correctly return the amount of
-**          buffer space required.  Also tests that it correctly handles a 
-**          buffer of insufficient space.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(locale_info_GetLocaleInfoW_test2_paltest_getlocaleinfow_test2, "locale_info/GetLocaleInfoW/test2/paltest_getlocaleinfow_test2")
-{    
-    WCHAR buffer[256] = { 0 };
-    int ret;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    ret = GetLocaleInfoW(LOCALE_NEUTRAL, LOCALE_SDECIMAL, buffer, 0);
-    if (ret != 2)
-    {
-        Fail("GetLocaleInfoW gave incorrect desired length for buffer.\n"
-            "Expected 2, got %d.\n", ret);
-    }
-
-    ret = GetLocaleInfoW(LOCALE_NEUTRAL, LOCALE_SDECIMAL, buffer, 1);
-    if (ret != 0)
-    {
-        Fail("GetLocaleInfoW expected to return 0, returned %d", ret);
-    }
-
-    if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
-    {
-        Fail("GetLocaleInfoW failed to set last error to "
-            "ERROR_INSUFFICIENT_BUFFER!\n");
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test1/test1.cpp
deleted file mode 100644
index bbd8ab11c00f69..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test1/test1.cpp
+++ /dev/null
@@ -1,80 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test1.c
-**
-** Purpose: Tests MultiByteToWideChar with all the ASCII characters (0-127).
-**          Also tests that WideCharToMultiByte handles different buffer
-**          lengths correctly (0, -1, and a valid length)
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-/*
- * For now, it is assumed that MultiByteToWideChar will only be used in the PAL
- * with CP_ACP, and that dwFlags will be 0.
- */
-
-PALTEST(locale_info_MultiByteToWideChar_test1_paltest_multibytetowidechar_test1, "locale_info/MultiByteToWideChar/test1/paltest_multibytetowidechar_test1")
-{    
-    char mbStr[128];
-    WCHAR wideStr[128];
-    int ret;
-    int i;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    for (i=0; i<128; i++)
-    {
-        mbStr[i] = 127 - i;
-        wideStr[i] = 0;
-    }
-
-
-    ret = MultiByteToWideChar(CP_ACP, 0, mbStr, -1, wideStr, 0);
-    if (ret != 128)
-    {
-        Fail("MultiByteToWideChar did not return correct string length!\n"
-            "Got %d, expected %d\n", ret, 128);
-    }
-
-    /* Make sure the ASCII set (0-127) gets translated correctly */
-    ret = MultiByteToWideChar(CP_ACP, 0, mbStr, -1, wideStr, 128);
-    if (ret != 128)
-    {
-        Fail("MultiByteToWideChar did not return correct string length!\n"
-            "Got %d, expected %d\n", ret, 128);
-    }
-
-    for (i=0; i<128; i++)
-    {
-        if (wideStr[i] != (WCHAR)(127 - i))
-        {
-            Fail("MultiByteToWideChar failed to translate correctly!\n"
-                "Expected character %d to be %c (%x), got %c (%x)\n",
-                i, 127 - i, 127 - i,wideStr[i], wideStr[i]);
-        }
-    }
-
-
-    /* try a 0 length string */
-    mbStr[0] = 0;
-    ret = MultiByteToWideChar(CP_ACP, 0, mbStr, -1, wideStr, 0);
-    if (ret != 1)
-    {
-        Fail("MultiByteToWideChar did not return correct string length!\n"
-            "Got %d, expected %d\n", ret, 1);
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test2/test2.cpp b/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test2/test2.cpp
deleted file mode 100644
index e98b03db070fea..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test2/test2.cpp
+++ /dev/null
@@ -1,67 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test2.c
-**
-** Purpose: Tests that MultiByteToWideChar respects the length of the wide 
-**          character string.
-
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-/*
- * For now, it is assumed that MultiByteToWideChar will only be used in the PAL
- * with CP_ACP, and that dwFlags will be 0.
- */
-
-PALTEST(locale_info_MultiByteToWideChar_test2_paltest_multibytetowidechar_test2, "locale_info/MultiByteToWideChar/test2/paltest_multibytetowidechar_test2")
-{    
-    char mbStr[128];
-    WCHAR wideStr[128];
-    int ret;
-    int i;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    for (i=0; i<128; i++)
-    {
-        mbStr[i] = 'a';
-        wideStr[i] = 0;
-    }
-
-    mbStr[127] = 0;
-
-
-    ret = MultiByteToWideChar(CP_ACP, 0, mbStr, 10, wideStr, 0);
-    if (ret != 10)
-    {
-        Fail("MultiByteToWideChar did not return correct string length!\n"
-            "Got %d, expected %d\n", ret, 10);
-    }
-
-    wideStr[10] = (WCHAR) 'b';
-
-    ret = MultiByteToWideChar(CP_ACP, 0, mbStr, 10, wideStr, 128);
-    if (ret != 10)
-    {
-        Fail("MultiByteToWideChar did not return correct string length!\n"
-            "Got %d, expected %d\n", ret, 10);
-    }
-
-    if (wideStr[10] != 'b')
-    {
-        Fail("WideCharToMultiByte overflowed the destination buffer!\n");
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test3/test3.cpp b/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test3/test3.cpp
deleted file mode 100644
index 2e36b3e3a145b2..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test3/test3.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test3.c
-**
-** Purpose: Tests that MultiByteToWideChar correctly handles the following 
-**          error conditions: insufficient buffer space, invalid code pages,
-**          and invalid flags.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(locale_info_MultiByteToWideChar_test3_paltest_multibytetowidechar_test3, "locale_info/MultiByteToWideChar/test3/paltest_multibytetowidechar_test3")
-{    
-    char mbStr[128];
-    WCHAR wideStr[128];
-    int ret;
-    int i;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    for (i=0; i<128; i++)
-    {
-        mbStr[i] = 'a';
-        wideStr[i] = 0;
-    }
-
-    mbStr[127] = 0;
-
-    /* try with insufficient buffer space */
-    ret = MultiByteToWideChar(CP_ACP, 0, mbStr, -1, wideStr, 10);
-    if (ret != 0)
-    {
-        Fail("MultiByteToWideChar did not return an error!\n"
-            "Expected return of 0, got %d", ret);
-    }
-
-    ret = GetLastError();
-    if (ret != ERROR_INSUFFICIENT_BUFFER)
-    {
-        Fail("MultiByteToWideChar did not set the last error to "
-            "ERROR_INSUFFICIENT_BUFFER!\n");
-    }
-
-    /* try with a wacky code page */
-    ret = MultiByteToWideChar(-1, 0, mbStr, -1, wideStr, 128);
-    if (ret != 0)
-    {
-        Fail("MultiByteToWideChar did not return an error!\n"
-            "Expected return of 0, got %d", ret);
-    }
-
-    ret = GetLastError();
-    if (ret != ERROR_INVALID_PARAMETER)
-    {
-        Fail("MultiByteToWideChar did not set the last error to "
-            "ERROR_INVALID_PARAMETER!\n");
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test4/test4.cpp b/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test4/test4.cpp
deleted file mode 100644
index 39bdbb1a11d0f0..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/MultiByteToWideChar/test4/test4.cpp
+++ /dev/null
@@ -1,282 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test4.c
-**
-** Purpose: Tests MultiByteToWideChar with a UTF-8 encoding
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-#include <minipal/utf8.h>
-
-PALTEST(locale_info_MultiByteToWideChar_test4_paltest_multibytetowidechar_test4, "locale_info/MultiByteToWideChar/test4/paltest_multibytetowidechar_test4")
-{    
-    int ret;
-    int ret2;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    const char * const utf8Strings[] =
-    {
-        // Correct strings
-        
-        // Empty string
-        "",
-        // 1 byte encoded 1 character long string
-        "A",
-        // 2 byte encoded 1 character long string
-        "\xC2\x80",
-        // 3 byte encoded 1 character long string
-        "\xE0\xA0\x80",
-        // 1 byte encoded characters only
-        "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
-        // valid 2 byte encoded characters only
-        "\xC2\x80\xC3\xBF\xC7\x81\xDF\xBF",
-        // valid 3 byte encoded characters only
-        "\xE0\xA0\x80\xE1\xB6\x88\xE1\x80\x80\xEF\xBF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 1 byte char
-        "\x41\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF\x45",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 1 byte char, ending with 2 byte one
-        "\x41\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 2 byte char, ending with 1 byte one
-        "\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF\x45",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 2 byte char
-        "\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 1 byte char
-        "\x41\x42\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF\x45\x46",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 1 byte char, ending with 2 byte one
-        "\x41\x42\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 2 byte char, ending with 1 byte one
-        "\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF\x45\x46",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 2 byte char
-        "\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF",
-        // surrogates
-        "\xF0\x90\x80\x80\xF0\x90\x89\x80\xF3\x80\x8E\xB0\xF4\x8F\xBF\xBF",
-        
-        // Strings with errors
-        // Incomplete 2 byte encoded character 1 byte missing standalone
-        "\xC2",
-        // Incomplete 3 byte encoded character 1 byte missing standalone
-        "\xE0\xA0",
-        // Incomplete 3 byte encoded character 2 bytes missing standalone
-        "\xE0",
-        // Incomplete surrogate character 1 byte missing standalone
-        "\xF0\x90\x80",
-        // Incomplete surrogate character 2 bytes missing standalone
-        "\xF0\x90",
-        // Incomplete surrogate character 3 bytes missing standalone
-        "\xF0",
-        // Trailing byte with no lead byte standalone
-        "\x80",
-        // Incomplete 2 byte encoded character 1 byte missing between 1 byte chars
-        "\x41\xC2\x42",
-        // Incomplete 3 byte encoded character 1 byte missing between 1 byte chars
-        "\x41\xE0\xA0\x42",
-        // Incomplete 3 byte encoded character 2 bytes missing between 1 byte chars
-        "\x41\xE0\x42",
-        // Trailing byte with no lead byte between 1 byte chars
-        "\x41\x80\x42",
-        // Incomplete 2 byte encoded character 1 byte missing before 1 byte char
-        "\xC2\x42",
-        // Incomplete 3 byte encoded character 1 byte missing before 1 byte char
-        "\xE0\xA0\x42",
-        // Incomplete 3 byte encoded character 2 bytes missing before 1 byte char
-        "\xE0\x42",
-        // Trailing byte with no lead byte before 1 byte char
-        "\x80\x42",
-        // Incomplete 2 byte encoded character 1 byte missing after 1 byte char
-        "\x41\xC2",
-        // Incomplete 3 byte encoded character 1 byte missing after 1 byte char
-        "\x41\xE0\xA0",
-        // Incomplete 3 byte encoded character 2 bytes missing after 1 byte char
-        "\x41\xE0",
-        // Trailing byte with no lead byte after 1 byte char
-        "\x41\x80",        
-        // Incomplete 2 byte encoded character 1 byte missing between 2 byte chars
-        "\xC2\x80\xC2\xC3\xBF",
-        // Incomplete 3 byte encoded character 1 byte missing between 2 byte chars
-        "\xC2\x80\xE0\xA0\xC3\xBF",
-        // Incomplete 3 byte encoded character 2 bytes missing between 2 byte chars
-        "\xC2\x80\xE0\xC3\xBF",
-        // Trailing byte with no lead byte between 2 byte chars
-        "\xC2\x80\x80\xC3\xBF",
-        // 2 byte encoded character in non-shortest form encodings (these are not allowed)
-        "\xC0\x80",
-        // 3 byte encoded character in non-shortest form encodings (these are not allowed)
-        "\xE0\x80\x80",
-        // 4 byte encoded character in non-shortest form encodings (these are not allowed)
-        "\xF0\x80\x80\x80",
-    };
-
-    const WCHAR * const unicodeStrings[] =
-    {
-        // Empty string
-        W(""),
-        // 1 byte encoded 1 character long string
-        W("A"),
-        // 2 byte encoded 1 character long string
-        W("\x0080"),
-        // 3 byte encoded 1 character long string
-        W("\x0800"),
-        // 1 byte encoded characters only
-        W("ABCDEFGHIJKLMNOPQRSTUVWXYZ"),
-        // 2 byte encoded characters only
-        W("\x0080\x00FF\x01C1\x07FF"),
-        // valid 3 byte encoded characters only
-        W("\x0800\x1D88\x1000\xFFFF"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 1 byte char
-        W("\x0041\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF\x0045"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 1 byte char, ending with 2 byte one
-        W("\x0041\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 2 byte char, ending with 1 byte one
-        W("\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF\x0045"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 2 byte char
-        W("\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 1 byte char
-        W("\x0041\x0042\x0080\x00FF\x0043\x0044\x01C1\x07FF\x0045\x0046"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 1 byte char, ending with 2 byte one
-        W("\x0041\x0042\x0080\x00FF\x0043\x0044\x01C1\x07FF"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 2 byte char, ending with 1 byte one
-        W("\x0080\x00FF\x0043\x0044\x01C1\x07FF\x0045\x0046"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 2 byte char
-        W("\x0080\x00FF\x0043\x0044\x01C1\x07FF"),
-        // surrogates
-        W("\xD800\xDC00\xD800\xDE40\xDAC0\xDFB0\xDBFF\xDFFF"),
-
-        // Strings with errors
-        // Incomplete 2 byte encoded character standalone
-        W("\xFFFD"),
-        // Incomplete 3 byte encoded character 1 byte missing standalone
-        W("\xFFFD"),
-        // Incomplete 3 byte encoded character 2 bytes missing standalone
-        W("\xFFFD"),
-        // Incomplete surrogate character 1 byte missing standalone
-        W("\xFFFD"),
-        // Incomplete surrogate character 2 bytes missing standalone
-        W("\xFFFD"),
-        // Incomplete surrogate character 3 bytes missing standalone
-        W("\xFFFD"),
-        // Trailing byte with no lead byte standalone
-        W("\xFFFD"),
-        // Incomplete 2 byte encoded character 1 byte missing between 1 byte chars
-        W("\x0041\xFFFD\x0042"),
-        // Incomplete 3 byte encoded character 1 byte missing between 1 byte chars
-        W("\x0041\xFFFD\x0042"),
-        // Incomplete 3 byte encoded character 2 bytes missing between 1 byte chars
-        W("\x0041\xFFFD\x0042"),
-        // Trailing byte with no lead byte between 1 byte chars
-        W("\x0041\xFFFD\x0042"),
-        // Incomplete 2 byte encoded character 1 byte missing before 1 byte char
-        W("\xFFFD\x0042"),
-        // Incomplete 3 byte encoded character 1 byte missing before 1 byte char
-        W("\xFFFD\x0042"),
-        // Incomplete 3 byte encoded character 2 bytes missing before 1 byte char
-        W("\xFFFD\x0042"),
-        // Trailing byte with no lead byte before 1 byte char
-        W("\xFFFD\x0042"),
-        // Incomplete 2 byte encoded character 1 byte missing after 1 byte char
-        W("\x0041\xFFFD"),
-        // Incomplete 3 byte encoded character 1 byte missing after 1 byte char
-        W("\x0041\xFFFD"),
-        // Incomplete 3 byte encoded character 2 bytes missing after 1 byte char
-        W("\x0041\xFFFD"),
-        // Trailing byte with no lead byte after 1 byte char
-        W("\x0041\xFFFD"),
-        // Incomplete 2 byte encoded character 1 byte missing between 2 byte chars
-        W("\x0080\xFFFD\x00FF"),
-        // Incomplete 3 byte encoded character 1 byte missing between 2 byte chars
-        W("\x0080\xFFFD\x00FF"),
-        // Incomplete 3 byte encoded character 2 bytes missing between 2 byte chars
-        W("\x0080\xFFFD\x00FF"),
-        // Trailing byte with no lead byte between 2 byte chars
-        W("\x0080\xFFFD\x00FF"),
-        // 2 byte encoded character in non-shortest form encodings (these are not allowed)
-        W("\xFFFD\xFFFD"),
-        // 3 byte encoded character in non-shortest form encodings (these are not allowed)
-        W("\xFFFD\xFFFD"),
-        // 4 byte encoded character in non-shortest form encodings (these are not allowed)
-        W("\xFFFD\xFFFD\xFFFD"),
-    };
-
-    for (int i = 0; i < (sizeof(utf8Strings) / sizeof(utf8Strings[0])); i++)
-    {
-        ret = MultiByteToWideChar(CP_UTF8, 0, utf8Strings[i], -1, NULL, 0);
-        WCHAR* wideBuffer = (WCHAR*)malloc(ret * sizeof(WCHAR));
-        ret2 = MultiByteToWideChar(CP_UTF8, 0, utf8Strings[i], -1, wideBuffer, ret);
-        if (ret != ret2)
-        {
-            Fail("MultiByteToWideChar string %d: returned different string length for empty and real dest buffers!\n"
-                "Got %d for the empty one, %d for real one.\n", i, ret2, ret);
-        }
-        
-        if (wcscmp(wideBuffer, unicodeStrings[i]) != 0)
-        {
-            Fail("MultiByteToWideChar string %d: the resulting string doesn't match the expected one!\n", i);
-        }
-        
-        free(wideBuffer);
-    }
-
-    {
-        // U+6F22 — code unit > U+00FF catches long-code-path bugs that move
-        // only the low byte instead of performing a full 16-bit byte swap.
-        const char utf8[] = "\xE6\xBC\xA2";
-        WCHAR wide[1] = { 0 };
-        size_t n = minipal_convert_utf8_to_utf16(utf8, sizeof(utf8) - 1, (CHAR16_T*)wide, 1, 0);
-        if (n != 1 || wide[0] != 0x6F22)
-            Fail("utf8->utf16 produced 0x%04x (n=%zu)\n", wide[0], n);
-
-#if BIGENDIAN
-        wide[0] = 0;
-        n = minipal_convert_utf8_to_utf16(utf8, sizeof(utf8) - 1, (CHAR16_T*)wide, 1, MINIPAL_TREAT_AS_LITTLE_ENDIAN);
-        if (n != 1 || wide[0] != 0x226F)
-            Fail("treat-as-LE utf8->utf16 produced 0x%04x (n=%zu)\n", wide[0], n);
-#endif
-    }
-
-#if BIGENDIAN
-    {
-        const char* ascii = "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456";
-        const size_t asciiLengthWithTerminator = strlen(ascii) + 1;
-        const unsigned int flags = MINIPAL_TREAT_AS_LITTLE_ENDIAN;
-
-        size_t requiredLength = minipal_get_length_utf8_to_utf16(ascii, asciiLengthWithTerminator, flags);
-        if (requiredLength != asciiLengthWithTerminator)
-        {
-            Fail("minipal_get_length_utf8_to_utf16 with MINIPAL_TREAT_AS_LITTLE_ENDIAN returned %zu, expected %zu\n",
-                requiredLength, asciiLengthWithTerminator);
-        }
-
-        WCHAR wideBuffer[64];
-        size_t convertedLength = minipal_convert_utf8_to_utf16(ascii, asciiLengthWithTerminator,
-            (CHAR16_T*)wideBuffer, sizeof(wideBuffer) / sizeof(wideBuffer[0]), flags);
-
-        if (convertedLength != asciiLengthWithTerminator)
-        {
-            Fail("minipal_convert_utf8_to_utf16 with MINIPAL_TREAT_AS_LITTLE_ENDIAN returned %zu, expected %zu\n",
-                convertedLength, asciiLengthWithTerminator);
-        }
-
-        for (size_t i = 0; i < asciiLengthWithTerminator; i++)
-        {
-            WCHAR expected = (WCHAR)(((unsigned char)ascii[i]) << 8);
-            if (wideBuffer[i] != expected)
-            {
-                Fail("minipal_convert_utf8_to_utf16 with MINIPAL_TREAT_AS_LITTLE_ENDIAN mismatch at %zu: got 0x%04x expected 0x%04x\n",
-                    i, wideBuffer[i], expected);
-            }
-        }
-    }
-#endif
-   
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test1/test1.cpp
deleted file mode 100644
index e8197b8c11b4c3..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test1/test1.cpp
+++ /dev/null
@@ -1,101 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test1.c
-**
-** Purpose: Tests WideCharToMultiByte with all the ASCII characters (0-127).
-**          Also tests that WideCharToMultiByte handles different buffer
-**          lengths correctly (0, -1, and a valid length)
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-PALTEST(locale_info_WideCharToMultiByte_test1_paltest_widechartomultibyte_test1, "locale_info/WideCharToMultiByte/test1/paltest_widechartomultibyte_test1")
-{    
-    char mbStr[128];
-    WCHAR wideStr[128];
-    int ret;
-    int i;
-    int k;
-    BOOL bRet=TRUE;
-
-    /* These codepages are currently supported by the PAL */
-    int codePages[] ={
-        CP_ACP,
-        CP_UTF8
-    };
-
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-
-    /* Go through all of the code pages */
-    for(i=0; i<(sizeof(codePages)/sizeof(int)); i++)
-    {
-
-        for (k=0; k<128; k++)
-        {
-            wideStr[k] = 127 - k;
-            mbStr[k] = 0;
-        }
-
-        /* Convert with buffer size of 0 */
-        ret = WideCharToMultiByte(codePages[i], 0, wideStr, -1, 
-                                  mbStr, 0, NULL, NULL);
-        if (ret != 128)
-        {
-            Trace("WideCharToMultiByte did not return correct string length!\n"
-                  "Got %d, expected %d for code page %d with error %u.\n", 
-                  ret, 128,codePages[i],GetLastError());
-            bRet=FALSE;
-        }
-
-        /* Make sure the ASCII set (0-127) gets translated correctly */
-        ret = WideCharToMultiByte(codePages[i], 0, wideStr, -1, 
-                                  mbStr, 128, NULL, NULL);
-        if (ret != 128)
-        {
-            Trace("WideCharToMultiByte did not return correct string length!\n"
-                  "Got %d, expected %d for code page %d with error %u.\n", 
-                  ret, 128,codePages[i],GetLastError());
-            bRet=FALSE;
-        }
-
-        for (k=0; k<128; k++)
-        {
-            if (mbStr[k] != 127 - k)
-            {
-                Trace("WideCharToMultiByte failed to translate correctly!\n"
-                      "Expected character %d to be %c (%x), got %c (%x) for "
-                      "code page %d\n",k, 127 - k, 127 - k,mbStr[k], mbStr[k],
-                      codePages[i]);
-                bRet=FALSE;
-            }
-        }
-
-
-        /* try a 0 length string ("") */
-        wideStr[0] = '\0';
-        ret = WideCharToMultiByte(codePages[i], 0, wideStr, -1, 
-                                  mbStr, 0, NULL, NULL);
-        if (ret != 1)
-        {
-            Trace("WideCharToMultiByte did not return correct string length!\n"
-                  "Got %d, expected %d for code page %d with error %u.\n", 
-                  ret, 1,codePages[i],GetLastError());
-            bRet=FALSE;
-        }
-    }
-
-    int result = bRet ? PASS : FAIL;
-    PAL_TerminateEx(result);
-    return result;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test2/test2.cpp b/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test2/test2.cpp
deleted file mode 100644
index 611b1b92b1b1fa..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test2/test2.cpp
+++ /dev/null
@@ -1,87 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test2.c
-**
-** Purpose: Tests that WideCharToMultiByte respects the length of the wide 
-**          character string.
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-
-
-PALTEST(locale_info_WideCharToMultiByte_test2_paltest_widechartomultibyte_test2, "locale_info/WideCharToMultiByte/test2/paltest_widechartomultibyte_test2")
-{    
-    char mbStr[128];
-    WCHAR wideStr[128];
-    int ret;
-    int i;
-    int k;
-    BOOL bRet=TRUE;
-
-    /* These codepages are currently supported by the PAL */
-    int codePages[] ={
-        CP_ACP,
-        CP_UTF8
-    };
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    /* Go through all of the code pages */
-    for(i=0; i<(sizeof(codePages)/sizeof(int)); i++)
-    {
-
-        /* Filling the arrays */
-        for (k=0; k<128; k++)
-        {
-            wideStr[k] = 'a';
-            mbStr[i] = 0;
-        }
-
-        wideStr[127] = 0;
-
-        /* Passing a buffer that is too small */
-        ret = WideCharToMultiByte(codePages[i], 0, wideStr, 10, 
-                                  mbStr, 0, NULL, NULL);
-        if (ret != 10)
-        {
-            Trace("WideCharToMultiByte did not return correct string length!\n"
-                  "Got %d, expected %d for %d with error %u.\n", ret, 10, 
-                  codePages[i], GetLastError());
-            bRet = FALSE;
-        }
-
-        /* Passing a sufficiently large buffer */
-        mbStr[10] = 'b';
-        ret = WideCharToMultiByte(codePages[i], 0, wideStr, 10, 
-                                  mbStr, 128, NULL, NULL);
-        if (ret != 10)
-        {
-            Trace("WideCharToMultiByte did not return correct string length!\n"
-                  "Got %d, expected %d for code page %d with error %u.\n", 
-                  ret, 10, codePages[i], GetLastError());
-            bRet = FALSE;
-        }
-
-        /* Verifying overflow of the destination string did not occur */
-        if (mbStr[10] != 'b')
-        {
-            Trace("WideCharToMultiByte overflowed the destination buffer for "
-                  "code page %d.\n", codePages[i]);
-            bRet = FALSE;
-        }
-
-    }
-
-    int result = bRet ? PASS : FAIL;
-    PAL_TerminateEx(result);
-    return result;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test3/test3.cpp b/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test3/test3.cpp
deleted file mode 100644
index 3bb816dcb88332..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test3/test3.cpp
+++ /dev/null
@@ -1,99 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test3.c
-**
-** Purpose: Tests that WideCharToMultiByte correctly handles the following 
-**          error conditions: insufficient buffer space, invalid code pages,
-**          and invalid flags.
-**
-**
-**==========================================================================*/
-
-
-#include <palsuite.h>
-
-
-PALTEST(locale_info_WideCharToMultiByte_test3_paltest_widechartomultibyte_test3, "locale_info/WideCharToMultiByte/test3/paltest_widechartomultibyte_test3")
-{    
-    char mbStr[128];
-    WCHAR wideStr[128];
-    int ret;
-    int i;
-    int k;
-    BOOL bRet=TRUE;
-
-    /* These codepages are currently supported by the PAL */
-    int codePages[] ={
-        CP_ACP,
-        CP_UTF8
-    };
-
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    /* Go through all of the code pages */
-    for(i=0; i<(sizeof(codePages)/sizeof(int)); i++)
-    {
-    
-        for (k=0; k<128; k++)
-        {
-            wideStr[k] = 'a';
-            mbStr[k] = 0;
-        }
-
-        wideStr[127] = 0;
-
-        /* try with insufficient buffer space */
-        ret = WideCharToMultiByte(codePages[i], 0, wideStr, -1, 
-                                  mbStr, 10, NULL, NULL);
-        if (ret != 0)
-        {
-            Trace("WideCharToMultiByte did not return an error!\n"
-                  "Expected return of 0, got %d for code page %d.\n", ret, 
-                  codePages[i]);
-            bRet = FALSE;
-        }
-
-        ret = GetLastError();
-        if (ret != ERROR_INSUFFICIENT_BUFFER)
-        {
-            Fail("WideCharToMultiByte set the last error to %u instead of "
-                 "ERROR_INSUFFICIENT_BUFFER for code page %d.\n",
-                 GetLastError(),codePages[i]);
-            bRet = FALSE;
-        }
-    }
-
-    /* Return failure if any of the code pages returned the wrong results */
-    if(!bRet)
-    {
-        return FAIL;
-    }
-
-    /* try with a wacky code page */
-    ret = WideCharToMultiByte(-1, 0, wideStr, -1, mbStr, 128, NULL, NULL);
-    if (ret != 0)
-    {
-        Fail("WideCharToMultiByte did not return an error!\n"
-             "Expected return of 0, got %d for invalid code page.\n", ret);
-    }
-
-    ret = GetLastError();
-    if (ret != ERROR_INVALID_PARAMETER)
-    {
-        Fail("WideCharToMultiByte set the last error to %u instead of "
-             "ERROR_INVALID_PARAMETER for invalid code page -1.\n",
-             GetLastError());
-    }
-
-    PAL_Terminate();
-
-    return PASS;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test4/test4.cpp b/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test4/test4.cpp
deleted file mode 100644
index 19b5796bf1f593..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test4/test4.cpp
+++ /dev/null
@@ -1,130 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test4.c
-**
-** Purpose: Tests that WideCharToMultiByte correctly handles WC_NO_BEST_FIT_CHARS
-**
-**
-**==========================================================================*/
-
-
-#include <palsuite.h>
-
-/* C with a circumflex */
-char16_t ustr[2] = { 0x108, 0 };
-
-/* expected conversion when best fit is allowed on Windows */
-char* lpBestFitRes = "C";
-
-/* expected conversion when no default character is specified */
-char* lpResStr1 = "?";
-
-/* expected conversion when the default character is 'k' */
-char myDefaultChar = 'k';
-char* lpResStr2 = "k";
-
-int 
-TestWideCharToMultiByte(
-       IN UINT CodePage,
-       IN DWORD dwFlags,
-       IN LPCSTR lpDefaultChar,
-       IN LPSTR lpResStr)
-{
-  char mbstr[30];
-  int ret;
-  int testStatus = PASS;
-  BOOL usedDefaultChar = FALSE;
-
-  printf("WideCharToMultiByte (CodePage=%d, dwFlags=%#x, default=%c)\n",
-         CodePage, dwFlags, lpDefaultChar?*lpDefaultChar:' ');
-  ret = WideCharToMultiByte(CodePage, dwFlags, ustr, -1, mbstr, sizeof(mbstr), 
-                            lpDefaultChar, &usedDefaultChar);
-  if (ret != 0) {
-    printf("   converted C with circumflex to in Unicode to multibyte: "
-           "\"%s\"\n", mbstr);
-    printf("   used default character?: %d\n", usedDefaultChar);
-    if (strcmp(mbstr, lpResStr) != 0 || usedDefaultChar != TRUE) 
-    {
-       printf("!!!! failed conversion !!!!\n");
-       testStatus = FAIL;
-    }
-  }
-  else {
-    printf("!!!! failed conversion !!!!\n");
-    testStatus = FAIL;
-  }
-  return testStatus;
-}
-
-PALTEST(locale_info_WideCharToMultiByte_test4_paltest_widechartomultibyte_test4, "locale_info/WideCharToMultiByte/test4/paltest_widechartomultibyte_test4")
-{    
-  int testStatus = PASS;
-
-  if (PAL_Initialize(argc, argv))
-  {
-      return FAIL;
-  }
-
-  /* Use WideCharToMultiByte to convert the string in code page CP_ACP.
-   * Note that the resulting string will be different on Windows PAL and 
-   * Unix PAL. On Windows, the default best fit behavior will map C with 
-   * circumflex to C. 
-   * 
-   *   testStatus |= TestWideCharToMultiByte(CP_ACP, 0, NULL, lpBestFitRes);
-   *
-   * On Unix, where there is no support for finding best fit, it will be 
-   * mapped to a '?'. In addition, it will trigger an ASSERT in the dbg/chk
-   * builds.
-   *
-   *   testStatus |= TestWideCharToMultiByte(CP_ACP, 0, NULL, lpResStr1);
-   */
-
-  /* Use WideCharToMultiByte with WC_NO_BEST_FIR_CHARS to convert the string 
-   * in CP_ACP (1252 by default). This will prevent it from mapping the C 
-   * with circumflex to its closest match in the ANSI code page: C
-   */
-  testStatus |= TestWideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, NULL, lpResStr1);
-
-
-  /* Use WideCharToMultiByte with WC_NO_BEST_FIR_CHARS and a default character 
-   * to convert the string. This will prevent it from mapping the C with 
-   * circumflex to its closest match in the ANSI code page: C. It will be
-   * replaced with the specified default character.
-   */
-  testStatus |= TestWideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, &myDefaultChar, lpResStr2);
-
-  /* Use WideCharToMultiByte to convert the string in code page 1253 
-   * Note that the resulting string will be different on Windows PAL and 
-   * Unix PAL. On Windows, the default best fit behavior will map C with 
-   * circumflex to C. 
-   * 
-   *   testStatus |= TestWideCharToMultiByte(1253, 0, NULL, lpBestFitRes);
-   *
-   * On Unix, where there is no support for finding best fit, it will be 
-   * mapped to a '?'. In addition, it will trigger an ASSERT in the dbg/chk
-   * builds.
-   *
-   *   testStatus |= TestWideCharToMultiByte(1253, 0, NULL, lpResStr1);
-   */
-
-  /* Use WideCharToMultiByte with WC_NO_BEST_FIR_CHARS to convert the string 
-   * in 1253. This will prevent it from mapping the C 
-   * with circumflex to its closest match in the ANSI code page: C
-   */
-  testStatus |= TestWideCharToMultiByte(1253, WC_NO_BEST_FIT_CHARS, NULL, lpResStr1);
-
-  /* Use WideCharToMultiByte with WC_NO_BEST_FIR_CHARS and a default 
-   * character to convert the string in 1253. This will prevent it from 
-   * mapping the C with circumflex to its closest match in the ANSI code 
-   * page: C. It will be replaced with the specified default character.
-   */
-  testStatus |= TestWideCharToMultiByte(1253, WC_NO_BEST_FIT_CHARS, &myDefaultChar, lpResStr2);
-
-  PAL_TerminateEx(testStatus);
-
-  return testStatus;
-}
-
diff --git a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test5/test5.cpp b/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test5/test5.cpp
deleted file mode 100644
index c968e5cca7a4aa..00000000000000
--- a/src/coreclr/pal/tests/palsuite/locale_info/WideCharToMultiByte/test5/test5.cpp
+++ /dev/null
@@ -1,261 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================================
-**
-** Source: test4.c
-**
-** Purpose: Tests WideCharMultiByte with UTF-8 encoding
-**
-**
-**==========================================================================*/
-
-#include <palsuite.h>
-#include <minipal/utf8.h>
-
-PALTEST(locale_info_WideCharToMultiByte_test5_paltest_widechartomultibyte_test5, "locale_info/WideCharToMultiByte/test5/paltest_widechartomultibyte_test5")
-{    
-    int ret;
-    int ret2;
-
-    if (PAL_Initialize(argc, argv))
-    {
-        return FAIL;
-    }
-
-    const WCHAR * const unicodeStrings[] =
-    {
-        // Correct strings
-        
-        // Empty string
-        W(""),
-        // 1 byte encoded 1 character long string
-        W("A"),
-        // 2 byte encoded 1 character long string
-        W("\x0080"),
-        // 3 byte encoded 1 character long string
-        W("\x0800"),
-        // 1 byte encoded characters only
-        W("ABCDEFGHIJKLMNOPQRSTUVWXYZ"),
-        // 2 byte encoded characters only
-        W("\x0080\x00FF\x01C1\x07FF"),
-        // valid 3 byte encoded characters only
-        W("\x0800\x1D88\x1000\xFFFF"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 1 byte char
-        W("\x0041\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF\x0045"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 1 byte char, ending with 2 byte one
-        W("\x0041\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 2 byte char, ending with 1 byte one
-        W("\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF\x0045"),
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 2 byte char
-        W("\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 1 byte char
-        W("\x0041\x0042\x0080\x00FF\x0043\x0044\x01C1\x07FF\x0045\x0046"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 1 byte char, ending with 2 byte one
-        W("\x0041\x0042\x0080\x00FF\x0043\x0044\x01C1\x07FF"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 2 byte char, ending with 1 byte one
-        W("\x0080\x00FF\x0043\x0044\x01C1\x07FF\x0045\x0046"),
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 2 byte char
-        W("\x0080\x00FF\x0043\x0044\x01C1\x07FF"),
-        // Surrogates
-        W("\xD800\xDC00\xD800\xDE40\xDAC0\xDFB0\xDBFF\xDFFF"),
-
-        // Strings with errors
-        
-        // Single high surrogate
-        W("\xD800"),
-        // Single low surrogate
-        W("\xDC00"),
-        // Character followed by single high surrogate
-        W("\x0041\xD800"),
-        // Character followed by single low surrogate
-        W("\x0041\xDC00"),
-        // Single high surrogate between two characters
-        W("\x0041\xD800\x0042"),
-        // Single low surrogate between two characters
-        W("\x0041\xDC00\x0042"),
-        // 256 single high surrogates
-        W("\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800"
-        "\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800\xD800")
-    };
-    
-    const char * const utf8Strings[] =
-    {
-        // Correct strings
-        
-        // Empty string
-        "",
-        // 1 byte encoded 1 character long string
-        "A",
-        // 2 byte encoded 1 character long string
-        "\xC2\x80",
-        // 3 byte encoded 1 character long string
-        "\xE0\xA0\x80",
-        // 1 byte encoded characters only
-        "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
-        // valid 2 byte encoded characters only
-        "\xC2\x80\xC3\xBF\xC7\x81\xDF\xBF",
-        // valid 3 byte encoded characters only
-        "\xE0\xA0\x80\xE1\xB6\x88\xE1\x80\x80\xEF\xBF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 1 byte char
-        "\x41\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF\x45",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 1 byte char, ending with 2 byte one
-        "\x41\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting with 2 byte char, ending with 1 byte one
-        "\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF\x45",
-        // 1 byte and 2 byte encoded characters interleaved 1:1 starting and ending with 2 byte char
-        "\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 1 byte char
-        "\x41\x42\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF\x45\x46",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 1 byte char, ending with 2 byte one
-        "\x41\x42\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting with 2 byte char, ending with 1 byte one
-        "\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF\x45\x46",
-        // 1 byte and 2 byte encoded characters interleaved 2:2 starting and ending with 2 byte char
-        "\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF",
-        // Surrogates
-        "\xF0\x90\x80\x80\xF0\x90\x89\x80\xF3\x80\x8E\xB0\xF4\x8F\xBF\xBF",
-        
-        // Strings with errors
-
-        // Single high surrogate
-        "\xEF\xBF\xBD",
-        // Single low surrogate
-        "\xEF\xBF\xBD",
-        // Character followed by single high surrogate
-        "\x41\xEF\xBF\xBD",
-        // Character followed by single low surrogate
-        "\x41\xEF\xBF\xBD",
-        // Single high surrogate between two characters
-        "\x41\xEF\xBF\xBD\x42",
-        // Single low surrogate between two characters
-        "\x41\xEF\xBF\xBD\x42",
-        // 256 single high surrogates
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-        "\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD"
-    };
-
-    for (int i = 0; i < (sizeof(unicodeStrings) / sizeof(unicodeStrings[0])); i++)
-    {
-        ret = WideCharToMultiByte(CP_UTF8, 0, unicodeStrings[i], -1, NULL, 0, NULL, NULL);
-        CHAR* utf8Buffer = (CHAR*)malloc(ret * sizeof(CHAR));
-        ret2 = WideCharToMultiByte(CP_UTF8, 0, unicodeStrings[i], -1, utf8Buffer, ret, NULL, NULL);
-        if (ret != ret2)
-        {
-            Fail("WideCharToMultiByte string %d: returned different string length for empty and real dest buffers!\n"
-                "Got %d for the empty one, %d for real one.\n", i, ret2, ret);
-        }
-        
-        if (strcmp(utf8Buffer, utf8Strings[i]) != 0)
-        {
-            Fail("WideCharToMultiByte string %d: the resulting string doesn't match the expected one!\n", i);
-        }
-        
-        free(utf8Buffer);
-    }
-
-    {
-        // U+6F22 — code unit > U+00FF catches long-code-path bugs that move
-        // only the low byte instead of performing a full 16-bit byte swap.
-        const WCHAR srcNative[1] = { 0x6F22 };
-        CHAR utf8[4] = { 0 };
-        size_t n = minipal_convert_utf16_to_utf8((const CHAR16_T*)srcNative, 1, utf8, sizeof(utf8), 0);
-        if (n != 3 || memcmp(utf8, "\xE6\xBC\xA2", 3) != 0)
-            Fail("utf16->utf8 produced %02x %02x %02x (n=%zu)\n",
-                (unsigned char)utf8[0], (unsigned char)utf8[1], (unsigned char)utf8[2], n);
-
-#if BIGENDIAN
-        // Stored little-endian (22 6F) reads as BE word 0x226F.
-        const WCHAR srcLE[1] = { 0x226F };
-        memset(utf8, 0, sizeof(utf8));
-        n = minipal_convert_utf16_to_utf8((const CHAR16_T*)srcLE, 1, utf8, sizeof(utf8), MINIPAL_TREAT_AS_LITTLE_ENDIAN);
-        if (n != 3 || memcmp(utf8, "\xE6\xBC\xA2", 3) != 0)
-            Fail("treat-as-LE utf16->utf8 produced %02x %02x %02x (n=%zu)\n",
-                (unsigned char)utf8[0], (unsigned char)utf8[1], (unsigned char)utf8[2], n);
-#endif
-    }
-
-#if BIGENDIAN
-    {
-        const char* expected = "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456";
-        const size_t expectedLengthWithTerminator = strlen(expected) + 1;
-        const unsigned int flags = MINIPAL_TREAT_AS_LITTLE_ENDIAN;
-
-        WCHAR littleEndianWide[64];
-        for (size_t i = 0; i < expectedLengthWithTerminator; i++)
-        {
-            littleEndianWide[i] = (WCHAR)(((unsigned char)expected[i]) << 8);
-        }
-
-        size_t requiredLength = minipal_get_length_utf16_to_utf8((const CHAR16_T*)littleEndianWide,
-            expectedLengthWithTerminator, flags);
-        if (requiredLength != expectedLengthWithTerminator)
-        {
-            Fail("minipal_get_length_utf16_to_utf8 with MINIPAL_TREAT_AS_LITTLE_ENDIAN returned %zu, expected %zu\n",
-                requiredLength, expectedLengthWithTerminator);
-        }
-
-        CHAR utf8Buffer[64];
-        size_t convertedLength = minipal_convert_utf16_to_utf8((const CHAR16_T*)littleEndianWide,
-            expectedLengthWithTerminator, utf8Buffer, sizeof(utf8Buffer), flags);
-        if (convertedLength != expectedLengthWithTerminator)
-        {
-            Fail("minipal_convert_utf16_to_utf8 with MINIPAL_TREAT_AS_LITTLE_ENDIAN returned %zu, expected %zu\n",
-                convertedLength, expectedLengthWithTerminator);
-        }
-
-        if (memcmp(utf8Buffer, expected, expectedLengthWithTerminator) != 0)
-        {
-            Fail("minipal_convert_utf16_to_utf8 with MINIPAL_TREAT_AS_LITTLE_ENDIAN produced unexpected bytes\n");
-        }
-    }
-#endif
-   
-    PAL_Terminate();
-
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadCodePtr/test1/test1.cpp b/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadCodePtr/test1/test1.cpp
deleted file mode 100644
index c3d4fe70c578c1..00000000000000
--- a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadCodePtr/test1/test1.cpp
+++ /dev/null
@@ -1,59 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================================
-**
-** Source: test1.c
-**
-** Purpose: Test to ensure that IsBadCodePtr return 0 when
-**          it can read memory or non zero when it can't.
-** 
-** Dependencies: PAL_Initialize
-**               PAL_Terminate
-**				 Fail
-** 
-
-**
-**===========================================================================*/
-
-#include <palsuite.h>
-
-/**
- * main
- * 
- * executable entry point
- */
-PALTEST(miscellaneous_IsBadCodePtr_test1_paltest_isbadcodeptr_test1, "miscellaneous/IsBadCodePtr/test1/paltest_isbadcodeptr_test1")
-{
-    BOOL ResultValue = 0;
-  
-    /*
-     * Initialize the PAL and return FAILURE if this fails
-     */
-
-    if(0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }     
-
-    /* This should be readable, and return 0 */
-    ResultValue = IsBadCodePtr((FARPROC)main);
-    if(ResultValue != 0) 
-    {
-        Fail("ERROR: IsBadCodePtr returned %d instead of 0, when pointing "
-             "at readable memory.\n",ResultValue);    
-    }
-
-    /* 0x00 is usually unreadable memory so the function should 
-       return non zero */
-    ResultValue = IsBadCodePtr((FARPROC)0x00);
-
-    if(ResultValue == 0)
-    {
-        Fail("ERROR: IsBadCodePtr returned %d instead of non zero  "
-             "when checking on unreadable memory.\n",ResultValue);
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadReadPtr/test1/test.cpp b/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadReadPtr/test1/test.cpp
deleted file mode 100644
index b0a2ab1762db76..00000000000000
--- a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadReadPtr/test1/test.cpp
+++ /dev/null
@@ -1,111 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================
-**
-** Source: test.c
-**
-** Purpose: IsBadReadPtr() function
-**
-**
-**=========================================================*/
-
-#include <palsuite.h>
-#include <sys/mman.h>
-
-#define MEMORY_AMOUNT 16
-
-PALTEST(miscellaneous_IsBadReadPtr_test1_paltest_isbadreadptr_test1, "miscellaneous/IsBadReadPtr/test1/paltest_isbadreadptr_test1")
-{
-    LPVOID TestingPointer = NULL;
-    BOOL ResultValue = 0;
-
-    /*
-     * Initialize the PAL and return FAILURE if this fails
-     */
-
-    if(0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-
-    TestingPointer = malloc(MEMORY_AMOUNT);
-    if ( TestingPointer == NULL )
-    {
-        Fail("ERROR: Failed to allocate memory for TestingPointer pointer. "
-           "Can't properly exec test case without this.");
-    }
-
-
-    /* This should be readable, and return 0 */
-    ResultValue = IsBadReadPtr(TestingPointer,MEMORY_AMOUNT);
-    if(ResultValue != 0)
-    {
-        free(TestingPointer);
-
-        Fail("ERROR: The function returned %d instead of 0, when pointing "
-             "at readable memory.",ResultValue);
-    }
-
-    /* If we pass 0, the result should be 0 as well */
-    ResultValue = IsBadReadPtr(TestingPointer,0);
-    if(ResultValue != 0)
-    {
-        free(TestingPointer);
-
-        Fail("ERROR: The function returned %d instead of 0, when the "
-             "function was passed a range of 0 bytes.",ResultValue);
-    }
-    free(TestingPointer); /* we are done with this */
-
-    /* create a readable address */
-    TestingPointer = mmap(NULL, 80, PROT_READ, MAP_ANON | MAP_PRIVATE, -1, 0);
-
-    if (TestingPointer == MAP_FAILED )
-    {
-        Fail("ERROR: call to mmap failed");
-    }
-
-    ResultValue = IsBadReadPtr(TestingPointer,16);
-    if(ResultValue != 0)
-    {
-        munmap(TestingPointer, 80);
-
-        Fail("ERROR: The function returned %d instead of 1 when checking "
-            "on unreadable memory.",ResultValue);
-    }
-
-    munmap(TestingPointer, 80);
-
-    /* create an unreadable address */
-    TestingPointer = mmap(NULL, 80, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0);
-
-    if (TestingPointer == MAP_FAILED )
-    {
-        Fail("ERROR: call to mmap failed");
-    }
-
-    ResultValue = IsBadReadPtr(TestingPointer,16);
-
-    if(ResultValue == 0)
-    {
-        munmap(TestingPointer, 80);
-
-        Fail("ERROR: The function returned %d instead of 1 when checking "
-             "on unreadable memory.",ResultValue);
-    }
-
-    munmap(TestingPointer, 80);
-
-
-    /* This should be unreadable and return 1 */
-    ResultValue = IsBadReadPtr(NULL,16);
-    if(ResultValue != 1)
-    {
-        Fail("ERROR: The function returned %d instead of 1 when checking "
-             "to see if NULL was readable.",ResultValue);
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test1/test.cpp b/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test1/test.cpp
deleted file mode 100644
index 64bd8022313fa7..00000000000000
--- a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test1/test.cpp
+++ /dev/null
@@ -1,81 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================
-**
-** Source: test.c
-**
-** Purpose: IsBadWritePtr() function
-**
-**
-**=========================================================*/
-
-#include <palsuite.h>
-
-#define MEMORY_AMOUNT 16
-
-PALTEST(miscellaneous_IsBadWritePtr_test1_paltest_isbadwriteptr_test1, "miscellaneous/IsBadWritePtr/test1/paltest_isbadwriteptr_test1")
-{
-    
-    void * TestingPointer = NULL;
-    BOOL ResultValue = 0;
-
-    /*
-     * Initialize the PAL and return FAILURE if this fails
-     */
-
-    if(0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-  
-    TestingPointer = malloc(MEMORY_AMOUNT);
-    if ( TestingPointer == NULL )
-    {
-	Fail("ERROR: Failed to allocate memory for TestingPointer pointer. "
-             "Can't properly exec test case without this.\n");
-    }
-
-
-    /* This should be writeable, return 0 */
-    ResultValue = IsBadWritePtr(TestingPointer,MEMORY_AMOUNT);
-
-    if(ResultValue != 0) 
-    {
-	free(TestingPointer);
-
-        Fail("ERROR: Returned %d when 0 should have been returned, checking "
-             "to see if writable memory is unwriteable.\n",ResultValue);
-    }
-
-    free(TestingPointer);
-  
-    /* This should be !writeable, return nonezero */
-    TestingPointer = (void*)0x08; /* non writeable address */
-    ResultValue = IsBadWritePtr(TestingPointer,sizeof(int));
-    
-    if(ResultValue == 0) 
-    {
-        Fail("ERROR: Returned %d when nonezero should have been returned, "
-             "checking to see if unwriteable memory  is writeable.\n",
-             ResultValue);
-    }
-  
-    /* This should be !writeable, return Nonezero */
-    ResultValue = IsBadWritePtr(NULL,MEMORY_AMOUNT);
-
-    if(ResultValue == 0) 
-    {
-        Fail("ERROR: Returned %d when nonezero should have been "
-	     "returned,checking "
-             "to see if a NULL pointer is writeable.\n",
-             ResultValue);
-    }
-    
-    PAL_Terminate();
-    return PASS;
-}
-
-
-
-
diff --git a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test2/test2.cpp b/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test2/test2.cpp
deleted file mode 100644
index 82bf114eb63012..00000000000000
--- a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test2/test2.cpp
+++ /dev/null
@@ -1,79 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================
-**
-** Source: test2.c
-**
-** Purpose:
-** Create three consecutive pages, NOACCESS, READWRITE and
-** NOACCESS. Check to ensure that the READWRITE page returns 0, to
-** ensure that IsBadWritePtr isn't overflowing. Also check the other two
-** pages to see that they return non-zero.
-**
-**
-**=========================================================*/
-
-#include <palsuite.h>
-#include <minipal/ospagesize.h>
-#include <sys/mman.h>
-
-PALTEST(miscellaneous_IsBadWritePtr_test2_paltest_isbadwriteptr_test2, "miscellaneous/IsBadWritePtr/test2/paltest_isbadwriteptr_test2")
-{
-    BYTE* baseAddress;
-    LPVOID PageOne;
-    LPVOID PageTwo;
-    LPVOID PageThree;
-    size_t pageSize = minipal_getpagesize();
-
-    if(0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-
-    baseAddress = static_cast<BYTE*>(mmap(NULL, pageSize * 4, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0));
-    if(baseAddress == MAP_FAILED)
-    {
-        Fail("ERROR: mmap failed to reserve the required memory.");
-    }
-
-    PageOne = baseAddress;
-    PageTwo = baseAddress + pageSize;
-    PageThree = baseAddress + (2 * pageSize);
-
-    if(mprotect(PageTwo, pageSize, PROT_READ | PROT_WRITE) != 0)
-    {
-        munmap(baseAddress, pageSize * 4);
-        Fail("ERROR: mprotect failed to make the middle page writable.");
-    }
-
-    if(IsBadWritePtr(PageOne,pageSize) == 0)
-    {
-        munmap(baseAddress, pageSize * 4);
-
-        Fail("ERROR: Called IsBadWritePtr on a page which was set NOACCESS "
-             "but the return value was 0, indicating that the memory is "
-             "writable.");
-    }
-
-    if(IsBadWritePtr(PageTwo,pageSize) != 0)
-    {
-        munmap(baseAddress, pageSize * 4);
-
-        Fail("ERROR: IsBadWritePtr didn't return 0 when called on a "
-             "page which should have been writable.");
-    }
-
-    if(IsBadWritePtr(PageThree,pageSize) == 0)
-    {
-        munmap(baseAddress, pageSize * 4);
-
-        Fail("ERROR: Called IsBadWritePtr on a page which was set NOACCESS "
-             "but the return value was 0, indicating that the memory is "
-             "writable.");
-    }
-
-    munmap(baseAddress, pageSize * 4);
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test3/test3.cpp b/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test3/test3.cpp
deleted file mode 100644
index 524682eb6845ee..00000000000000
--- a/src/coreclr/pal/tests/palsuite/miscellaneous/IsBadWritePtr/test3/test3.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================
-**
-** Source: test3.c
-**
-** Purpose:
-** Check that IsBadWritePtr returns non-zero on Read-only memory.
-**
-**
-**=========================================================*/
-
-#include <palsuite.h>
-#include <minipal/ospagesize.h>
-#include <sys/mman.h>
-
-PALTEST(miscellaneous_IsBadWritePtr_test3_paltest_isbadwriteptr_test3, "miscellaneous/IsBadWritePtr/test3/paltest_isbadwriteptr_test3")
-{
-    LPVOID PageOne;
-    size_t pageSize = minipal_getpagesize();
-
-    if(0 != (PAL_Initialize(argc, argv)))
-    {
-        return FAIL;
-    }
-
-    PageOne = mmap(NULL, pageSize, PROT_READ, MAP_ANON | MAP_PRIVATE, -1, 0);
-
-    if(PageOne == MAP_FAILED)
-    {
-        Fail("ERROR: mmap failed to create the required read-only memory.");
-    }
-
-    if(IsBadWritePtr(PageOne,pageSize) == 0)
-    {
-        munmap(PageOne, pageSize);
-
-        Fail("ERROR: IsBadWritePtr returned 0 when checking a section of "
-             "read-only memory. It should be non-zero.");
-    }
-
-    munmap(PageOne, pageSize);
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test1/PAL_RegisterLibraryW_UnregisterLibraryW.cpp b/src/coreclr/pal/tests/palsuite/pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test1/PAL_RegisterLibraryW_UnregisterLibraryW.cpp
deleted file mode 100644
index 0eab8ece1ff095..00000000000000
--- a/src/coreclr/pal/tests/palsuite/pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test1/PAL_RegisterLibraryW_UnregisterLibraryW.cpp
+++ /dev/null
@@ -1,63 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source: pal_registerlibrary_unregisterlibrary
-**
-** Purpose: Positive test the PAL_RegisterLibrary API and
-**          PAL_UnRegisterLibrary.
-**          Call PAL_RegisterLibrary to map a module into the calling
-**          process address space and call PAL_UnRegisterLibrary
-**          to unmap this module.
-**
-**
-**============================================================*/
-#define UNICODE
-#include <palsuite.h>
-
-PALTEST(pal_specific_PAL_RegisterLibraryW_UnregisterLibraryW_test1_paltest_pal_registerlibraryw_unregisterlibraryw_test1, "pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test1/paltest_pal_registerlibraryw_unregisterlibraryw_test1")
-{
-    HMODULE ModuleHandle;
-    char ModuleName[64];
-    WCHAR *wpModuleName = NULL;
-    int err;
-
-    /*Initialize the PAL environment*/
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        return FAIL;
-    }
-
-    /*zero the buffer*/
-    memset(ModuleName,0,64);
-    sprintf_s(ModuleName, ARRAY_SIZE(ModuleName), "%s", "rotor_pal");
-
-    /*convert a normal string to a wide one*/
-    wpModuleName = convert(ModuleName);
-
-    /*load a module*/
-    ModuleHandle = PAL_RegisterLibrary(wpModuleName);
-
-    /*free the memory*/
-    free(wpModuleName);
-
-    if(!ModuleHandle)
-    {
-        Fail("Failed to call PAL_RegisterLibrary API to map a module "
-            "into calling process, error code=%u!\n", GetLastError());
-    }
-
-    /*decrement the reference count of the loaded DLL*/
-    err = PAL_UnregisterLibrary(ModuleHandle);
-    if(0 == err)
-    {
-        Fail("\nFailed to call PAL_UnregisterLibrary API to "
-                "decrement the count of the loaded DLL module, "
-                "error code=%u!\n", GetLastError());
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test2_neg/reg_unreg_libraryw_neg.cpp b/src/coreclr/pal/tests/palsuite/pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test2_neg/reg_unreg_libraryw_neg.cpp
deleted file mode 100644
index 4d34414e72c26a..00000000000000
--- a/src/coreclr/pal/tests/palsuite/pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test2_neg/reg_unreg_libraryw_neg.cpp
+++ /dev/null
@@ -1,61 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*=============================================================
-**
-** Source: pal_registerlibraryw_unregisterlibraryw_neg.c
-**
-** Purpose: Negative test the PAL_RegisterLibrary API.
-**          Call PAL_RegisterLibrary to map a non-existent module
-**          into the calling process address space.
-**
-**
-**============================================================*/
-#define UNICODE
-#include <palsuite.h>
-
-PALTEST(pal_specific_PAL_RegisterLibraryW_UnregisterLibraryW_test2_neg_paltest_reg_unreg_libraryw_neg, "pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test2_neg/paltest_reg_unreg_libraryw_neg")
-{
-    HMODULE ModuleHandle;
-    char ModuleName[64];
-    WCHAR *wpModuleName = NULL;
-    int err;
-
-    /*Initialize the PAL environment*/
-    err = PAL_Initialize(argc, argv);
-    if(0 != err)
-    {
-        return FAIL;
-    }
-
-    memset(ModuleName, 0, 64);
-    sprintf_s(ModuleName, ARRAY_SIZE(ModuleName), "%s", "not_exist_module_name");
-
-    /*convert a normal string to a wide one*/
-    wpModuleName = convert(ModuleName);
-
-    /*load a not exist module*/
-    ModuleHandle = PAL_RegisterLibrary(wpModuleName);
-
-    /*free the memory*/
-    free(wpModuleName);
-
-    if(NULL != ModuleHandle)
-    {
-        Trace("ERROR: PAL_RegisterLibrary successfully mapped "
-              "a module that does not exist into the calling process\n");
-
-        /*decrement the reference count of the loaded DLL*/
-        err = PAL_UnregisterLibrary(ModuleHandle);
-        if(0 == err)
-        {
-            Trace("\nFailed to call PAL_UnregisterLibrary API to decrement the "
-                "count of the loaded DLL module!\n");
-        }
-        Fail("");
-
-    }
-
-    PAL_Terminate();
-    return PASS;
-}
diff --git a/src/coreclr/pal/tests/palsuite/paltestlist.txt b/src/coreclr/pal/tests/palsuite/paltestlist.txt
index afd899d6d46468..b348aa0e5fdb26 100644
--- a/src/coreclr/pal/tests/palsuite/paltestlist.txt
+++ b/src/coreclr/pal/tests/palsuite/paltestlist.txt
@@ -1,19 +1,3 @@
-c_runtime/atof/test1/paltest_atof_test1
-c_runtime/atoi/test1/paltest_atoi_test1
-c_runtime/isalnum/test1/paltest_isalnum_test1
-c_runtime/isalpha/test1/paltest_isalpha_test1
-c_runtime/isdigit/test1/paltest_isdigit_test1
-c_runtime/isprint/test1/paltest_isprint_test1
-c_runtime/isprint/test2/paltest_isprint_test2
-c_runtime/isspace/test1/paltest_isspace_test1
-c_runtime/iswdigit/test1/paltest_iswdigit_test1
-c_runtime/iswspace/test1/paltest_iswspace_test1
-c_runtime/iswupper/test1/paltest_iswupper_test1
-c_runtime/isxdigit/test1/paltest_isxdigit_test1
-c_runtime/memchr/test1/paltest_memchr_test1
-c_runtime/memcmp/test1/paltest_memcmp_test1
-c_runtime/memmove/test1/paltest_memmove_test1
-c_runtime/memset/test1/paltest_memset_test1
 c_runtime/sscanf_s/test1/paltest_sscanf_test1
 c_runtime/sscanf_s/test10/paltest_sscanf_test10
 c_runtime/sscanf_s/test11/paltest_sscanf_test11
@@ -31,21 +15,6 @@ c_runtime/sscanf_s/test6/paltest_sscanf_test6
 c_runtime/sscanf_s/test7/paltest_sscanf_test7
 c_runtime/sscanf_s/test8/paltest_sscanf_test8
 c_runtime/sscanf_s/test9/paltest_sscanf_test9
-c_runtime/strcat/test1/paltest_strcat_test1
-c_runtime/strchr/test1/paltest_strchr_test1
-c_runtime/strcmp/test1/paltest_strcmp_test1
-c_runtime/strcpy/test1/paltest_strcpy_test1
-c_runtime/strlen/test1/paltest_strlen_test1
-c_runtime/strncat/test1/paltest_strncat_test1
-c_runtime/strncmp/test1/paltest_strncmp_test1
-c_runtime/strncpy/test1/paltest_strncpy_test1
-c_runtime/strpbrk/test1/paltest_strpbrk_test1
-c_runtime/strrchr/test1/paltest_strrchr_test1
-c_runtime/strstr/test1/paltest_strstr_test1
-c_runtime/tolower/test1/paltest_tolower_test1
-c_runtime/toupper/test1/paltest_toupper_test1
-c_runtime/towlower/test1/paltest_towlower_test1
-c_runtime/towupper/test1/paltest_towupper_test1
 c_runtime/wcscat/test1/paltest_wcscat_test1
 c_runtime/wcschr/test1/paltest_wcschr_test1
 c_runtime/wcscmp/test1/paltest_wcscmp_test1
@@ -63,9 +32,6 @@ c_runtime/wcstoul/test3/paltest_wcstoul_test3
 c_runtime/wcstoul/test4/paltest_wcstoul_test4
 c_runtime/wcstoul/test5/paltest_wcstoul_test5
 c_runtime/wcstoul/test6/paltest_wcstoul_test6
-c_runtime/_alloca/test1/paltest_alloca_test1
-c_runtime/_rotl/test1/paltest_rotl_test1
-c_runtime/_rotr/test1/paltest_rotr_test1
 c_runtime/_vsnprintf_s/test1/paltest_vsnprintf_test1
 c_runtime/_vsnprintf_s/test10/paltest_vsnprintf_test10
 c_runtime/_vsnprintf_s/test11/paltest_vsnprintf_test11
@@ -96,20 +62,9 @@ filemapping_memmgt/GetModuleFileNameA/test2/paltest_getmodulefilenamea_test2
 filemapping_memmgt/GetModuleFileNameW/test2/paltest_getmodulefilenamew_test2
 filemapping_memmgt/ProbeMemory/test1/paltest_probememory_test1
 filemapping_memmgt/ProbeMemory/ProbeMemory_neg1/paltest_probememory_probememory_neg1
-loader/LoadLibraryA/test2/paltest_loadlibrarya_test2
-loader/LoadLibraryA/test3/paltest_loadlibrarya_test3
-loader/LoadLibraryA/test5/paltest_loadlibrarya_test5
 loader/LoadLibraryW/test2/paltest_loadlibraryw_test2
 loader/LoadLibraryW/test3/paltest_loadlibraryw_test3
 loader/LoadLibraryW/test5/paltest_loadlibraryw_test5
-locale_info/MultiByteToWideChar/test1/paltest_multibytetowidechar_test1
-locale_info/MultiByteToWideChar/test2/paltest_multibytetowidechar_test2
-locale_info/MultiByteToWideChar/test3/paltest_multibytetowidechar_test3
-locale_info/MultiByteToWideChar/test4/paltest_multibytetowidechar_test4
-locale_info/WideCharToMultiByte/test1/paltest_widechartomultibyte_test1
-locale_info/WideCharToMultiByte/test2/paltest_widechartomultibyte_test2
-locale_info/WideCharToMultiByte/test3/paltest_widechartomultibyte_test3
-locale_info/WideCharToMultiByte/test5/paltest_widechartomultibyte_test5
 miscellaneous/CloseHandle/test2/paltest_closehandle_test2
 miscellaneous/FlushInstructionCache/test1/paltest_flushinstructioncache_test1
 miscellaneous/FormatMessageW/test1/paltest_formatmessagew_test1
diff --git a/src/coreclr/pal/tests/palsuite/paltestlist_to_be_reviewed.txt b/src/coreclr/pal/tests/palsuite/paltestlist_to_be_reviewed.txt
index aa4324c318988f..bd85a96c38855c 100644
--- a/src/coreclr/pal/tests/palsuite/paltestlist_to_be_reviewed.txt
+++ b/src/coreclr/pal/tests/palsuite/paltestlist_to_be_reviewed.txt
@@ -1,7 +1,6 @@
 This is a list of failing PAL tests that need to be reviewed because.
 They should either be fixed or deleted if they are no longer applicable.
 
-c_runtime/iswprint/test1/paltest_iswprint_test1
 debug_api/DebugBreak/test1/paltest_debugbreak_test1
 debug_api/OutputDebugStringA/test1/paltest_outputdebugstringa_test1
 exception_handling/pal_except/test1/paltest_pal_except_test1
@@ -29,32 +28,16 @@ filemapping_memmgt/GetModuleFileNameA/test1/paltest_getmodulefilenamea_test1
 filemapping_memmgt/GetModuleFileNameW/test1/paltest_getmodulefilenamew_test1
 filemapping_memmgt/GetProcAddress/test1/paltest_getprocaddress_test1
 filemapping_memmgt/GetProcAddress/test2/paltest_getprocaddress_test2
-loader/LoadLibraryA/test1/paltest_loadlibrarya_test1
-loader/LoadLibraryA/test6/paltest_loadlibrarya_test6
-loader/LoadLibraryA/test7/paltest_loadlibrarya_test7
-loader/LoadLibraryA/test8/paltest_loadlibrarya_test8
 loader/LoadLibraryW/test1/paltest_loadlibraryw_test1
-locale_info/CompareStringA/test1/paltest_comparestringa_test1
-locale_info/CompareStringW/test1/paltest_comparestringw_test1
-locale_info/GetLocaleInfoW/test1/paltest_getlocaleinfow_test1
-locale_info/GetLocaleInfoW/test2/paltest_getlocaleinfow_test2
-locale_info/WideCharToMultiByte/test4/paltest_widechartomultibyte_test4
 miscellaneous/FormatMessageW/test4/paltest_formatmessagew_test4
 miscellaneous/FormatMessageW/test5/paltest_formatmessagew_test5
 miscellaneous/FormatMessageW/test6/paltest_formatmessagew_test6
 miscellaneous/InterLockedExchangeAdd/test1/paltest_interlockedexchangeadd_test1
-miscellaneous/IsBadCodePtr/test1/paltest_isbadcodeptr_test1
-miscellaneous/IsBadReadPtr/test1/paltest_isbadreadptr_test1
-miscellaneous/IsBadWritePtr/test1/paltest_isbadwriteptr_test1
-miscellaneous/IsBadWritePtr/test2/paltest_isbadwriteptr_test2
-miscellaneous/IsBadWritePtr/test3/paltest_isbadwriteptr_test3
 pal_specific/PAL_get_stdout/test1/paltest_pal_get_stdout_test1
-pal_specific/PAL_RegisterLibraryW_UnregisterLibraryW/test1/paltest_pal_registerlibraryw_unregisterlibraryw_test1
 samples/test2/paltest_samples_test2
 threading/CreateThread/test2/paltest_createthread_test2
 threading/DuplicateHandle/test9/paltest_duplicatehandle_test9
 threading/ExitThread/test2/paltest_exitthread_test2
 threading/GetCurrentProcess/test1/paltest_getcurrentprocess_test1
 threading/GetCurrentThreadId/test1/paltest_getcurrentthreadid_test1
-threading/Sleep/test1/paltest_sleep_test1
 threading/TerminateProcess/test1/paltest_terminateprocess_test1
diff --git a/src/coreclr/pal/tests/palsuite/threading/Sleep/test1/Sleep.cpp b/src/coreclr/pal/tests/palsuite/threading/Sleep/test1/Sleep.cpp
deleted file mode 100644
index 043cfafb0f1827..00000000000000
--- a/src/coreclr/pal/tests/palsuite/threading/Sleep/test1/Sleep.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================
-**
-** Source: Sleep.c
-**
-** Purpose: Test to establish whether the Sleep function stops the thread from
-** executing for the specified times.
-**
-** Dependencies: Fail
-**               Trace
-**
-
-**
-**=========================================================*/
-
-#include <palsuite.h>
-
-PALTEST(threading_Sleep_test1_paltest_sleep_test1, "threading/Sleep/test1/paltest_sleep_test1")
-{
-    DWORD SleepTimes[] =
-    {
-        0,
-        50,
-        100,
-        500,
-        2000
-    };
-
-    /* Milliseconds of error which are acceptable Function execution time, etc. */
-    DWORD AcceptableTimeError = 150;
-
-    int64_t OldTimeStamp;
-    int64_t NewTimeStamp;
-    DWORD MaxDelta;
-    DWORD TimeDelta;
-    DWORD i;
-
-    if(0 != (PAL_Initialize(argc, argv)))
-    {
-        return ( FAIL );
-    }
-
-    for( i = 0; i < sizeof(SleepTimes) / sizeof(DWORD); i++)
-    {
-        OldTimeStamp = minipal_hires_ticks();
-        minipal_sleep(SleepTimes[i]);
-        NewTimeStamp = minipal_hires_ticks();
-
-        TimeDelta = (NewTimeStamp - OldTimeStamp) / (minipal_hires_tick_frequency() / 1000);
-
-        /* For longer intervals use a 10 percent tolerance */
-        if ((SleepTimes[i] * 0.1) > AcceptableTimeError)
-        {
-            MaxDelta = SleepTimes[i] + (DWORD)(SleepTimes[i] * 0.1);
-        }
-        else
-        {
-            MaxDelta = SleepTimes[i] + AcceptableTimeError;
-        }
-
-        if ( TimeDelta<SleepTimes[i] || TimeDelta>MaxDelta )
-        {
-            Fail("The sleep function slept for %d ms when it should have "
-             "slept for %d ms\n", TimeDelta, SleepTimes[i]);
-       }
-    }
-    PAL_Terminate();
-    return ( PASS );
-
-}
diff --git a/src/coreclr/pal/tests/palsuite/threading/Sleep/test2/sleep.cpp b/src/coreclr/pal/tests/palsuite/threading/Sleep/test2/sleep.cpp
deleted file mode 100644
index 74edfce80962f8..00000000000000
--- a/src/coreclr/pal/tests/palsuite/threading/Sleep/test2/sleep.cpp
+++ /dev/null
@@ -1,64 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/*============================================================
-**
-** Source: Sleep.c
-**
-** Purpose: Test to establish whether the Sleep function stops the thread from
-** executing for the specified times.
-**
-
-**
-**=========================================================*/
-
-#include <palsuite.h>
-
-PALTEST(threading_Sleep_test2_paltest_sleep_test2, "threading/Sleep/test2/paltest_sleep_test2")
-{
-    /*
-    * times in 10^(-3) seconds
-    */
-
-    DWORD SleepTimes[] =
-    {
-        60000,
-        300000,
-        1800000,
-        3200000
-    };
-
-    /* Milliseconds of error which are acceptable Function execution time, etc. */
-    DWORD AcceptableTimeError = 150;
-
-    int64_t OldTimeStamp;
-    int64_t NewTimeStamp;
-    DWORD MaxDelta;
-    DWORD TimeDelta;
-    DWORD i;
-
-    if(0 != (PAL_Initialize(argc, argv)))
-    {
-        return ( FAIL );
-    }
-
-    for( i = 0; i < sizeof(SleepTimes) / sizeof(DWORD); i++)
-    {
-        OldTimeStamp = minipal_hires_ticks();
-        minipal_sleep(SleepTimes[i]);
-        NewTimeStamp = minipal_hires_ticks();
-
-        TimeDelta = (NewTimeStamp - OldTimeStamp) / (minipal_hires_tick_frequency() / 1000);
-
-        MaxDelta = SleepTimes[i] + AcceptableTimeError;
-
-        if ( TimeDelta<SleepTimes[i] || TimeDelta>MaxDelta )
-        {
-            Fail("The sleep function slept for %u ms when it should have "
-             "slept for %u ms\n", TimeDelta, SleepTimes[i]);
-       }
-    }
-    PAL_Terminate();
-    return ( PASS );
-
-}
diff --git a/src/coreclr/scripts/genLttngProvider.py b/src/coreclr/scripts/genLttngProvider.py
index 24030925a22cdf..11e8ac976713a6 100644
--- a/src/coreclr/scripts/genLttngProvider.py
+++ b/src/coreclr/scripts/genLttngProvider.py
@@ -312,9 +312,9 @@ def generateMethodBody(template, providerName, eventName, runtimeFlavor):
         paramname   = fnparam.name
 
         if fnparam.winType == "win:UnicodeString":
-            result.append("    INT " + paramname + "_path_size = -1;\n")
+            result.append("    size_t " + paramname + "_path_size = 0;\n")
             result.append("    PathCharString " + paramname + "_PS;\n")
-            result.append("    INT " + paramname + "_full_name_path_size")
+            result.append("    size_t " + paramname + "_full_name_path_size")
             result.append(" = (lttng_strlen16(" + paramname + ") + 1)*sizeof(WCHAR);\n")
             result.append("    CHAR* " + paramname + "_full_name = ")
             result.append(paramname + "_PS.OpenStringBuffer(" + paramname + "_full_name_path_size );\n")
@@ -343,10 +343,10 @@ def generateMethodBody(template, providerName, eventName, runtimeFlavor):
             if ctf_type == "ctf_string" and wintypeName == "win:UnicodeString":
                 #emit code to convert unicode to ansi string
 
-                result.append("    " + paramname+ "_path_size = WideCharToMultiByte( CP_ACP, 0, ")
-                result.append(paramname + ", -1, ")
+                result.append("    " + paramname + "_path_size = minipal_convert_utf16_to_utf8((const CHAR16_T*)")
+                result.append(paramname + ", lttng_strlen16(" + paramname + ") + 1, ")
                 result.append(paramname + "_full_name, ")
-                result.append(paramname + "_full_name_path_size, NULL, NULL );\n")
+                result.append(paramname + "_full_name_path_size, 0);\n")
 
                 result.append("    _ASSERTE(" +paramname+ "_path_size < " )
                 result.append(paramname + "_full_name_path_size );\n    ")
@@ -581,6 +581,7 @@ def generateLttngFiles(etwmanifest, eventprovider_directory, runtimeFlavor, dryR
 #include "pal_error.h"
 #include "pal.h"
 #include "pal/stackstring.hpp"
+#include <minipal/utf8.h>
 """)
                 lttngimpl_file.write("#include \"" + lttngevntheadershortname + "\"\n\n")
 
diff --git a/src/coreclr/tools/metainfo/mdinfo.cpp b/src/coreclr/tools/metainfo/mdinfo.cpp
index c28e71f7549ec3..35f4d65d435340 100644
--- a/src/coreclr/tools/metainfo/mdinfo.cpp
+++ b/src/coreclr/tools/metainfo/mdinfo.cpp
@@ -198,7 +198,7 @@ const char *g_szNativeType[] =
 
 static const char* ConvertToUtf8(LPCWSTR name, _Out_writes_(bufLen) char* buffer, ULONG bufLen)
 {
-    int res = WideCharToMultiByte(CP_UTF8, 0, name, -1, buffer, bufLen, NULL, NULL);
+    size_t res = minipal_convert_utf16_to_utf8((const CHAR16_T*)name, u16_strlen(name) + 1, buffer, bufLen, 0);
     if (res == 0)
         buffer[0] = '\0';
     return buffer;
@@ -1955,7 +1955,7 @@ void MDInfo::DisplayCustomAttributeInfo(mdCustomAttribute inValue, const char *p
         LPWSTR pwzName = (LPWSTR)(new WCHAR[iLen]);
         if(pwzName)
         {
-            MultiByteToWideChar(CP_UTF8,0, pMethName,-1, pwzName,iLen);
+            minipal_convert_utf8_to_utf16(pMethName, strlen(pMethName) + 1, (CHAR16_T*)pwzName, iLen, 0);
             PrettyPrintSigLegacy(pSig, cbSig, pwzName, &qSigName, m_pImport);
             delete [] pwzName;
         }
diff --git a/src/coreclr/tools/metainfo/mdobj.cpp b/src/coreclr/tools/metainfo/mdobj.cpp
index 6fdc11a30ce89b..a4333df63b6147 100644
--- a/src/coreclr/tools/metainfo/mdobj.cpp
+++ b/src/coreclr/tools/metainfo/mdobj.cpp
@@ -204,8 +204,7 @@ void DisplayArchive(_In_z_ WCHAR* szFile, ULONG DumpFilter, _In_opt_z_ WCHAR* sz
     {
         if((szName = GetNameOfObj(pbLongNameAddress, (PIMAGE_ARCHIVE_MEMBER_HEADER)pbMapAddress, szBuf))!=NULL)
         {
-            if (MultiByteToWideChar(CP_ACP, 0, szName, -1, wzName, 1024) == -1)
-                MDInfo::Error("Conversion from Multi-Byte to Wide-Char failed.");
+            minipal_convert_utf8_to_utf16(szName, strlen(szName) + 1, (CHAR16_T*)wzName, 1024, 0);
 
             // Display metadata only for object files.
             // If szObjName is specified, display metadata only for that one object file.
diff --git a/src/coreclr/tools/superpmi/mcs/verbmerge.cpp b/src/coreclr/tools/superpmi/mcs/verbmerge.cpp
index 66c2f46a7ef768..60e1527b8f59cf 100644
--- a/src/coreclr/tools/superpmi/mcs/verbmerge.cpp
+++ b/src/coreclr/tools/superpmi/mcs/verbmerge.cpp
@@ -8,6 +8,7 @@
 #include "spmiutil.h"
 #include "config.h"
 #include <stdio.h>
+#include <minipal/utf8.h>
 #ifdef TARGET_UNIX
 #include <sys/types.h>
 #include <dirent.h>
@@ -44,21 +45,12 @@ LPWSTR verbMerge::MergePathStrings(LPCWSTR dir, LPCWSTR file)
     return newpath;
 }
 
-char* verbMerge::ConvertWideCharToMultiByte(LPCWSTR wstr)
+WCHAR* verbMerge::ConvertFromUtf8(LPCSTR str)
 {
-    unsigned int codePage   = CP_UTF8;
-    int          sizeNeeded = WideCharToMultiByte(codePage, 0, wstr, -1, NULL, 0, NULL, NULL);
-    char*        encodedStr = new char[sizeNeeded];
-    WideCharToMultiByte(codePage, 0, wstr, -1, encodedStr, sizeNeeded, NULL, NULL);
-    return encodedStr;
-}
-
-WCHAR* verbMerge::ConvertMultiByteToWideChar(LPCSTR str)
-{
-    unsigned int codePage   = CP_UTF8;
-    int          sizeNeeded = MultiByteToWideChar(codePage, 0, str, -1, NULL, 0);
-    WCHAR*       encodedStr = new WCHAR[sizeNeeded];
-    MultiByteToWideChar(codePage, 0, str, -1, encodedStr, sizeNeeded);
+    size_t length     = strlen(str) + 1;
+    size_t sizeNeeded = minipal_get_length_utf8_to_utf16(str, length, 0);
+    WCHAR* encodedStr = new WCHAR[sizeNeeded];
+    minipal_convert_utf8_to_utf16(str, length, (CHAR16_T*)encodedStr, sizeNeeded, 0);
     return encodedStr;
 }
 
@@ -73,20 +65,20 @@ int verbMerge::AppendFileRaw(FILE* hFileOut, LPCWSTR fileFullPath, unsigned char
 {
     int result = 0; // default to zero == success
 
-    char* fileNameAsChar = ConvertWideCharToMultiByte(fileFullPath);
-    LogInfo("Appending file '%s'", fileNameAsChar);
+    std::string fileNameAsChar = ConvertToUtf8(fileFullPath);
+    LogInfo("Appending file '%s'", fileNameAsChar.c_str());
 
     FILE* hFileIn;
     if (u16_fopen_s(&hFileIn, fileFullPath, W("rb")) != 0)
     {
-        LogError("Failed to open input file '%s'. errno=%d", fileNameAsChar, errno);
+        LogError("Failed to open input file '%s'. errno=%d", fileNameAsChar.c_str(), errno);
         return -1;
     }
 
     int64_t fileSize = fgetsize(hFileIn);
     if (fileSize < 0)
     {
-        LogError("fgetsize on '%s' failed. errno=%d", fileNameAsChar, errno);
+        LogError("fgetsize on '%s' failed. errno=%d", fileNameAsChar.c_str(), errno);
         result = -1;
         goto CLEAN_UP;
     }
@@ -96,7 +88,7 @@ int verbMerge::AppendFileRaw(FILE* hFileOut, LPCWSTR fileFullPath, unsigned char
         size_t bytesRead = fread(buffer, 1, bufferSize, hFileIn);
         if (ferror(hFileIn))
         {
-            LogError("Failed to read '%s' from offset %lld. errno=%d", fileNameAsChar, offset, errno);
+            LogError("Failed to read '%s' from offset %lld. errno=%d", fileNameAsChar.c_str(), offset, errno);
             result = -1;
             goto CLEAN_UP;
         }
@@ -111,8 +103,6 @@ int verbMerge::AppendFileRaw(FILE* hFileOut, LPCWSTR fileFullPath, unsigned char
 
 CLEAN_UP:
 
-    delete[] fileNameAsChar;
-
     if (fclose(hFileIn) != 0)
     {
         LogError("fclose failed. errno=%d", errno);
@@ -134,11 +124,10 @@ int verbMerge::AppendFile(FILE* hFileOut, LPCWSTR fileFullPath, bool dedup, unsi
 
     if (dedup)
     {
-        // Need to conver the fileFullPath to non-Unicode.
-        char* fileFullPathAsChar = ConvertWideCharToMultiByte(fileFullPath);
-        LogInfo("Appending file '%s'", fileFullPathAsChar);
-        bool ok = m_removeDups.CopyAndRemoveDups(fileFullPathAsChar, hFileOut);
-        delete[] fileFullPathAsChar;
+        // Need to convert the fileFullPath to non-Unicode.
+        std::string fileFullPathAsChar = ConvertToUtf8(fileFullPath);
+        LogInfo("Appending file '%s'", fileFullPathAsChar.c_str());
+        bool ok = m_removeDups.CopyAndRemoveDups(fileFullPathAsChar.c_str(), hFileOut);
         if (!ok)
         {
             LogError("Failed to remove dups");
@@ -318,7 +307,7 @@ int verbMerge::FilterDirectory(LPCWSTR                      dir,
                 continue;
 
             // Call the filter with &FindData like the Windows code below.
-            FindData findData(dirEntryType, ConvertMultiByteToWideChar(pEntry->d_name));
+            FindData findData(dirEntryType, ConvertFromUtf8(pEntry->d_name));
             if (filter(&findData))
             {
                 // Prepend it to the list.
@@ -502,26 +491,23 @@ int verbMerge::AppendAllInDir(FILE*              hFileOut,
 
 #else  // TARGET_WINDOWS
         struct stat fileStat;
-        char *fileFullPathUtf8 = ConvertWideCharToMultiByte(fileFullPath);
-        int st = stat(fileFullPathUtf8, &fileStat);
+        std::string fileFullPathUtf8 = ConvertToUtf8(fileFullPath);
+        int st = stat(fileFullPathUtf8.c_str(), &fileStat);
         if (st != 0)
         {
-            LogError("Failed to stat file '%s'. errno=%d", fileFullPathUtf8, errno);
+            LogError("Failed to stat file '%s'. errno=%d", fileFullPathUtf8.c_str(), errno);
             result = -1;
             delete[] fileFullPath;
-            delete[] fileFullPathUtf8;
             goto CLEAN_UP;
         }
-        delete[] fileFullPathUtf8;
         uint64_t fileSize = fileStat.st_size;
 #endif // TARGET_WINDOWS
 
         // Is it zero length? If so, skip it.
         if (fileSize == 0)
         {
-            char* fileFullPathAsChar = ConvertWideCharToMultiByte(fileFullPath);
-            LogInfo("Skipping zero-length file '%s'", fileFullPathAsChar);
-            delete[] fileFullPathAsChar;
+            std::string fileFullPathAsChar = ConvertToUtf8(fileFullPath);
+            LogInfo("Skipping zero-length file '%s'", fileFullPathAsChar.c_str());
         }
         else
         {
@@ -612,13 +598,8 @@ int verbMerge::DoWork(const char* nameOfOutputFile, const char* pattern, bool re
         }
     }
 
-    int    nameLength              = (int)strlen(nameOfOutputFile) + 1;
-    LPWSTR nameOfOutputFileAsWchar = new WCHAR[nameLength];
-    MultiByteToWideChar(CP_ACP, 0, nameOfOutputFile, -1, nameOfOutputFileAsWchar, nameLength);
-
-    int    patternLength  = (int)strlen(pattern) + 1;
-    LPWSTR patternAsWchar = new WCHAR[patternLength];
-    MultiByteToWideChar(CP_ACP, 0, pattern, -1, patternAsWchar, patternLength);
+    LPWSTR nameOfOutputFileAsWchar = ConvertFromUtf8(nameOfOutputFile);
+    LPWSTR patternAsWchar          = ConvertFromUtf8(pattern);
 
     FILE* hFileOut = fopen(nameOfOutputFile, "wb");
     if (hFileOut == nullptr)
diff --git a/src/coreclr/tools/superpmi/mcs/verbmerge.h b/src/coreclr/tools/superpmi/mcs/verbmerge.h
index e03ad869600ca1..c02a4bd4958d17 100644
--- a/src/coreclr/tools/superpmi/mcs/verbmerge.h
+++ b/src/coreclr/tools/superpmi/mcs/verbmerge.h
@@ -80,8 +80,7 @@ class verbMerge
 
     static LPWSTR MergePathStrings(LPCWSTR dir, LPCWSTR file);
 
-    static char* ConvertWideCharToMultiByte(LPCWSTR wstr);
-    static WCHAR* ConvertMultiByteToWideChar(LPCSTR str);
+    static WCHAR* ConvertFromUtf8(LPCSTR str);
 
     static int AppendFileRaw(FILE* hFileOut, LPCWSTR fileFullPath, unsigned char* buffer, size_t bufferSize);
     static int AppendFile(FILE* hFileOut, LPCWSTR fileFullPath, bool dedup, unsigned char* buffer, size_t bufferSize);
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
index 1044df01ba7581..139319a5288e8e 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
+++ b/src/coreclr/tools/superpmi/superpmi-shared/spmiutil.cpp
@@ -13,6 +13,7 @@
 #include <iomanip>
 #include <minipal/debugger.h>
 #include <minipal/random.h>
+#include <minipal/utf8.h>
 
 static bool breakOnDebugBreakorAV = false;
 
@@ -585,11 +586,10 @@ std::string getClassName(MethodContext* mc, CORINFO_CLASS_HANDLE clsHnd)
 
 std::string ConvertToUtf8(const WCHAR* str)
 {
-    unsigned len = WideCharToMultiByte(CP_UTF8, 0, str, -1, nullptr, 0, nullptr, nullptr);
-    if (len == 0)
-        return{};
+    size_t length = u16_strlen(str) + 1;
+    size_t len    = minipal_get_length_utf16_to_utf8((const CHAR16_T*)str, length, 0);
 
     std::vector<char> buf(len + 1);
-    WideCharToMultiByte(CP_UTF8, 0, str, -1, buf.data(), len + 1, nullptr, nullptr);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)str, length, buf.data(), len + 1, 0);
     return std::string{ buf.data() };
 }
diff --git a/src/coreclr/tools/superpmi/superpmi/jithost.cpp b/src/coreclr/tools/superpmi/superpmi/jithost.cpp
index 5bf155d9d0d1ca..4c7b22ac1282a4 100644
--- a/src/coreclr/tools/superpmi/superpmi/jithost.cpp
+++ b/src/coreclr/tools/superpmi/superpmi/jithost.cpp
@@ -8,6 +8,7 @@
 #include "jithost.h"
 
 #include <clrconfignocache.h>
+#include <minipal/utf8.h>
 
 WCHAR* GetPrefixedEnvironmentVariable(const WCHAR* prefix, size_t prefixLen, const WCHAR* key, JitInstance& jitInstance)
 {
@@ -46,18 +47,11 @@ WCHAR* GetPrefixedEnvironmentVariable(const WCHAR* prefix, size_t prefixLen, con
 // the returned value must be freed with jitInstance.freeLongLivedArray(value).
 char* GetConfigFromEnvironmentVariable(const char* key, JitInstance& jitInstance)
 {
-    int keyLen = MultiByteToWideChar(CP_UTF8, 0, key, -1, nullptr, 0);
-    if (keyLen == 0)
-    {
-        return nullptr;
-    }
+    size_t keyLength = strlen(key) + 1;
+    size_t keyLen    = minipal_get_length_utf8_to_utf16(key, keyLength, 0);
 
     WCHAR* keyUtf8 = new WCHAR[keyLen];
-    if (MultiByteToWideChar(CP_UTF8, 0, key, -1, keyUtf8, keyLen) == 0)
-    {
-        delete[] keyUtf8;
-        return nullptr;
-    }
+    minipal_convert_utf8_to_utf16(key, keyLength, (CHAR16_T*)keyUtf8, keyLen, 0);
 
     WCHAR* result = GetPrefixedEnvironmentVariable(DOTNET_PREFIX, LEN_OF_DOTNET_PREFIX, keyUtf8, jitInstance);
     if (result == nullptr)
@@ -72,21 +66,11 @@ char* GetConfigFromEnvironmentVariable(const char* key, JitInstance& jitInstance
         return nullptr;
     }
 
-    int resultLen = WideCharToMultiByte(CP_UTF8, 0, result, -1, nullptr, 0, nullptr, nullptr);
-    if (resultLen == 0)
-    {
-        jitInstance.freeLongLivedArray(result);
-        return nullptr;
-    }
-
-    char* resultUtf8 = (char*)jitInstance.allocateLongLivedArray((size_t)resultLen);
+    size_t resultLength = u16_strlen(result) + 1;
+    size_t resultLen    = minipal_get_length_utf16_to_utf8((const CHAR16_T*)result, resultLength, 0);
 
-    if (WideCharToMultiByte(CP_UTF8, 0, result, -1, resultUtf8, resultLen, nullptr, nullptr) == 0)
-    {
-        jitInstance.freeLongLivedArray(result);
-        jitInstance.freeLongLivedArray(resultUtf8);
-        return nullptr;
-    }
+    char* resultUtf8 = (char*)jitInstance.allocateLongLivedArray(resultLen);
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)result, resultLength, resultUtf8, resultLen, 0);
 
     jitInstance.freeLongLivedArray(result);
 
diff --git a/src/coreclr/utilcode/fstring.cpp b/src/coreclr/utilcode/fstring.cpp
index 6b4c7988a207ee..3abe6936657533 100644
--- a/src/coreclr/utilcode/fstring.cpp
+++ b/src/coreclr/utilcode/fstring.cpp
@@ -63,22 +63,16 @@ HRESULT Unicode_Utf8_Length(_In_z_ LPCWSTR pString, _Out_ bool * pAllAscii, _Out
 
         * pLength = (DWORD) (p - pString);
     }
-    else // use WideCharToMultiByte to calculate result length
+    else
     {
-        * pLength = WideCharToMultiByte(CP_UTF8, 0, pString, -1, NULL, 0, NULL, NULL);
+        size_t length = minipal_get_length_utf16_to_utf8((const CHAR16_T*)pString, u16_strlen(pString), 0);
 
-        if (*pLength == 0)
-        {
-            return HRESULT_FROM_GetLastError();
-        }
-
-        // Remove the count of null terminator, to be consistent with the all-ASCII case.
-        --*pLength;
-
-        if (*pLength > MAX_LENGTH)
+        if (length > MAX_LENGTH)
         {
             return COR_E_OVERFLOW;
         }
+
+        * pLength = (DWORD)length;
     }
 
     return S_OK;
@@ -131,11 +125,9 @@ HRESULT Unicode_Utf8(_In_z_ LPCWSTR pString, bool allAscii, _Out_writes_bytes_(l
     }
     else
     {
-        length = WideCharToMultiByte(CP_UTF8, 0, pString, -1, pBuffer, (int) length + 1, NULL, NULL);
-
-        if (length == 0)
+        if (minipal_convert_utf16_to_utf8((const CHAR16_T*)pString, u16_strlen(pString), pBuffer, length, 0) == 0)
         {
-            return HRESULT_FROM_GetLastError();
+            return HRESULT_FROM_WIN32(errno);
         }
     }
 
@@ -185,20 +177,14 @@ HRESULT Utf8_Unicode_Length(_In_z_ LPCSTR pString, _Out_ bool * pAllAscii, _Out_
     }
     else
     {
-        * pLength = MultiByteToWideChar(CP_UTF8, 0, pString, -1, NULL, 0);
+        size_t length = minipal_get_length_utf8_to_utf16(pString, strlen(pString), 0);
 
-        if (* pLength == 0)
-        {
-            return HRESULT_FROM_GetLastError();
-        }
-
-        // Remove the count of null terminator, to be consistent with the all-ASCII case.
-        --*pLength;
-
-        if (* pLength > MAX_LENGTH)
+        if (length > MAX_LENGTH)
         {
             return COR_E_OVERFLOW;
         }
+
+        * pLength = (DWORD)length;
     }
 
     return S_OK;
@@ -252,11 +238,9 @@ HRESULT Utf8_Unicode(_In_z_ LPCSTR pString, bool allAscii, _Out_writes_bytes_(le
     }
     else
     {
-        length = MultiByteToWideChar(CP_UTF8, 0, pString, -1, pBuffer, (int) length + 1);
-
-        if (length == 0)
+        if (minipal_convert_utf8_to_utf16(pString, strlen(pString), (CHAR16_T*)pBuffer, length, 0) == 0)
         {
-            return HRESULT_FROM_GetLastError();
+            return HRESULT_FROM_WIN32(errno);
         }
     }
 
diff --git a/src/coreclr/utilcode/sstring.cpp b/src/coreclr/utilcode/sstring.cpp
index 276615aa22f581..8329fbd6bb5964 100644
--- a/src/coreclr/utilcode/sstring.cpp
+++ b/src/coreclr/utilcode/sstring.cpp
@@ -750,8 +750,6 @@ void SString::ConvertToUnicode(SString &s) const
     }
     CONTRACTL_END;
 
-    int page = 0;
-
     switch (GetRepresentation())
     {
     case REPRESENTATION_EMPTY:
@@ -765,7 +763,6 @@ void SString::ConvertToUnicode(SString &s) const
         return;
 
     case REPRESENTATION_UTF8:
-        page = CP_UTF8;
         break;
 
     case REPRESENTATION_ASCII:
@@ -777,15 +774,12 @@ void SString::ConvertToUnicode(SString &s) const
         UNREACHABLE();
     }
 
-    COUNT_T length = MultiByteToWideChar(page, 0, GetRawANSI(), GetRawCount()+1, 0, 0);
-    if (length == 0)
-        ThrowLastError();
+    size_t length = minipal_get_length_utf8_to_utf16(GetRawUTF8(), GetRawCount() + 1, 0);
 
-    s.Resize(length-1, REPRESENTATION_UNICODE);
+    s.Resize((COUNT_T)(length - 1), REPRESENTATION_UNICODE);
 
-    length = MultiByteToWideChar(page, 0, GetRawANSI(), GetRawCount()+1, s.GetRawUnicode(), length);
-    if (length == 0)
-        ThrowLastError();
+    if (minipal_convert_utf8_to_utf16(GetRawUTF8(), GetRawCount() + 1, (CHAR16_T*)s.GetRawUnicode(), length, 0) == 0)
+        ThrowWin32(errno);
 
     _ASSERTE(s.IsRepresentation(REPRESENTATION_UNICODE));
 }
@@ -2218,7 +2212,6 @@ bool SString::DacGetUnicode(COUNT_T                                   cBufChars,
     SUPPORTS_DAC;
 
     PVOID pContent = NULL;
-    int iPage = CP_ACP;
 
     if (IsEmpty() || (GetRepresentation() == REPRESENTATION_EMPTY))
     {
@@ -2265,22 +2258,24 @@ bool SString::DacGetUnicode(COUNT_T                                   cBufChars,
             return true;
 
         case REPRESENTATION_UTF8:
-            iPage = CP_UTF8;
-            FALLTHROUGH;
         case REPRESENTATION_ASCII:
-            // iPage defaults to CP_ACP.
+        {
+            PSTR pString = reinterpret_cast<PSTR>(pContent);
+            size_t length = strlen(pString) + 1;
             if (pcNeedChars)
             {
-                *pcNeedChars = MultiByteToWideChar(iPage, 0, reinterpret_cast<PSTR>(pContent), -1, NULL, 0);
+                size_t cchNeed = minipal_get_length_utf8_to_utf16(pString, length, 0);
+                *pcNeedChars = (COUNT_T)cchNeed;
             }
             if (pBuffer && cBufChars)
             {
-                if (!MultiByteToWideChar(iPage, 0, reinterpret_cast<PSTR>(pContent), -1, pBuffer, cBufChars))
+                if (minipal_convert_utf8_to_utf16(pString, length, (CHAR16_T*)pBuffer, cBufChars, 0) == 0)
                 {
                     return false;
                 }
             }
             return true;
+        }
 
         default:
             DacNotImpl();
diff --git a/src/coreclr/utilcode/util.cpp b/src/coreclr/utilcode/util.cpp
index ee97461e39d2ec..c107192b94cf52 100644
--- a/src/coreclr/utilcode/util.cpp
+++ b/src/coreclr/utilcode/util.cpp
@@ -1622,9 +1622,9 @@ HRESULT Utf2Quick(
     CONTRACTL_END;
 
     HRESULT     hr = S_OK;              // A result.
-    int         iReqLen;                // Required additional length.
-    int         iActLen;
-    int         bAlloc = 0;             // If non-zero, allocation was required.
+    size_t      cchReq;                 // Required additional length.
+    size_t      cchAct;
+    bool        bAlloc = false;         // If true, allocation was required.
 
     if (iCurLen < 0 )
     {
@@ -1634,7 +1634,7 @@ HRESULT Utf2Quick(
 
     // Calculate the space available
     S_SIZE_T cchAvail = S_SIZE_T(rStr.MaxSize()) - S_SIZE_T(iCurLen);
-    if (cchAvail.IsOverflow() || cchAvail.Value() > INT_MAX)
+    if (cchAvail.IsOverflow())
     {
         _ASSERTE_MSG(false, "Integer overflow/underflow");
         return HRESULT_FROM_WIN32(ERROR_ARITHMETIC_OVERFLOW);
@@ -1647,21 +1647,31 @@ HRESULT Utf2Quick(
         _ASSERTE_MSG(false, "Integer overflow/underflow");
         return HRESULT_FROM_WIN32(ERROR_ARITHMETIC_OVERFLOW);
     }
-    iReqLen = MultiByteToWideChar(CP_UTF8, 0, pStr, -1, rNewStr, (int)(cchAvail.Value()));
+    size_t cchSrc = strlen(pStr) + 1;
+    cchReq = minipal_convert_utf8_to_utf16(pStr, cchSrc, (CHAR16_T*)rNewStr, cchAvail.Value(), 0);
 
     // If the buffer was too small, determine what is required.
-    if (iReqLen == 0)
-        bAlloc = iReqLen = MultiByteToWideChar(CP_UTF8, 0, pStr, -1, 0, 0);
+    if (cchReq == 0)
+    {
+        cchReq = minipal_get_length_utf8_to_utf16(pStr, cchSrc, 0);
+        bAlloc = true;
+    }
     // Resize the buffer.  If the buffer was large enough, this just sets the internal
     //  counter, but if it was too small, this will attempt a reallocation.  Note that
     //  the length includes the terminating W('/0').
-    IfFailGo(rStr.ReSizeNoThrow(iCurLen+iReqLen));
+    S_SIZE_T newSize = S_SIZE_T(iCurLen) + S_SIZE_T(cchReq);
+    if (newSize.IsOverflow())
+    {
+        _ASSERTE_MSG(false, "Integer overflow/underflow");
+        return HRESULT_FROM_WIN32(ERROR_ARITHMETIC_OVERFLOW);
+    }
+    IfFailGo(rStr.ReSizeNoThrow(newSize.Value()));
     // If we had to realloc, then do the conversion again, now that the buffer is
     //  large enough.
     if (bAlloc) {
         //recalculating cchAvail since MaxSize could have been changed.
         cchAvail = S_SIZE_T(rStr.MaxSize()) - S_SIZE_T(iCurLen);
-        if (cchAvail.IsOverflow() || cchAvail.Value() > INT_MAX)
+        if (cchAvail.IsOverflow())
         {
             _ASSERTE_MSG(false, "Integer overflow/underflow");
             return HRESULT_FROM_WIN32(ERROR_ARITHMETIC_OVERFLOW);
@@ -1674,8 +1684,8 @@ HRESULT Utf2Quick(
         _ASSERTE_MSG(false, "Integer overflow/underflow");
         return HRESULT_FROM_WIN32(ERROR_ARITHMETIC_OVERFLOW);
         }
-        iActLen = MultiByteToWideChar(CP_UTF8, 0, pStr, -1, rNewStr, (int)(cchAvail.Value()));
-        _ASSERTE(iReqLen == iActLen);
+        cchAct = minipal_convert_utf8_to_utf16(pStr, cchSrc, (CHAR16_T*)rNewStr, cchAvail.Value(), 0);
+        _ASSERTE(cchReq == cchAct);
     }
 ErrExit:
     return hr;
diff --git a/src/coreclr/vm/assemblyspec.cpp b/src/coreclr/vm/assemblyspec.cpp
index 38d82e2a5c1149..4c02d60c09dfc7 100644
--- a/src/coreclr/vm/assemblyspec.cpp
+++ b/src/coreclr/vm/assemblyspec.cpp
@@ -427,12 +427,12 @@ HRESULT AssemblySpec::EmitToken(
         AMD.usRevisionNumber = m_context.usRevisionNumber;
 
         if (m_context.szLocale) {
-            AMD.cbLocale = MultiByteToWideChar(CP_UTF8, 0, m_context.szLocale, -1, NULL, 0);
-            if(AMD.cbLocale==0)
-                IfFailGo(HRESULT_FROM_GetLastError());
-            AMD.szLocale = (LPWSTR) alloca(AMD.cbLocale * sizeof(WCHAR) );
-            if(MultiByteToWideChar(CP_UTF8, 0, m_context.szLocale, -1, AMD.szLocale, AMD.cbLocale)==0)
-                IfFailGo(HRESULT_FROM_GetLastError());
+            size_t cchLocale = strlen(m_context.szLocale) + 1;
+            size_t cchWideLocale = minipal_get_length_utf8_to_utf16(m_context.szLocale, cchLocale, 0);
+            AMD.cbLocale = (ULONG)cchWideLocale;
+            AMD.szLocale = (LPWSTR) alloca(cchWideLocale * sizeof(WCHAR) );
+            if(minipal_convert_utf8_to_utf16(m_context.szLocale, cchLocale, (CHAR16_T*)AMD.szLocale, cchWideLocale, 0)==0)
+                IfFailGo(HRESULT_FROM_WIN32(errno));
         }
         else {
             AMD.cbLocale = 0;
diff --git a/src/coreclr/vm/cdacstress.cpp b/src/coreclr/vm/cdacstress.cpp
index ceebbd3aeae559..b36763b2e0b38a 100644
--- a/src/coreclr/vm/cdacstress.cpp
+++ b/src/coreclr/vm/cdacstress.cpp
@@ -1345,7 +1345,7 @@ static void ResolveMethodNameFromMD(CLRDATA_ADDRESS mdAddr, char* buf, int bufLe
         unsigned int nameLen = 0;
         if (SUCCEEDED(s_cdacSosDac->GetMethodDescName(mdAddr, ARRAY_SIZE(wname), wname, &nameLen)) && nameLen > 0)
         {
-            WideCharToMultiByte(CP_UTF8, 0, wname, -1, buf, bufLen, NULL, NULL);
+            minipal_convert_utf16_to_utf8((const CHAR16_T*)wname, u16_strlen(wname) + 1, buf, bufLen, 0);
             return;
         }
     }
@@ -2307,7 +2307,7 @@ static void ResolveMethodName(CLRDATA_ADDRESS source, int sourceType, char* buf,
             unsigned int nameLen = 0;
             if (SUCCEEDED(pSos->GetMethodDescName(mdAddr, ARRAY_SIZE(wname), wname, &nameLen)) && nameLen > 0)
             {
-                WideCharToMultiByte(CP_UTF8, 0, wname, -1, buf, bufLen, NULL, NULL);
+                minipal_convert_utf16_to_utf8((const CHAR16_T*)wname, u16_strlen(wname) + 1, buf, bufLen, 0);
                 return;
             }
         }
diff --git a/src/coreclr/vm/commtmemberinfomap.cpp b/src/coreclr/vm/commtmemberinfomap.cpp
index 83037b47854413..483206643e3a06 100644
--- a/src/coreclr/vm/commtmemberinfomap.cpp
+++ b/src/coreclr/vm/commtmemberinfomap.cpp
@@ -744,9 +744,10 @@ void ComMTMemberInfoMap::GetMethodPropsForMeth(
         if (i < 0)
         {
             // Save the name.  Have to convert from UTF8.
-            int iLen = MultiByteToWideChar(CP_UTF8, 0, pPropName, -1, 0, 0);
+            size_t cchPropName = strlen(pPropName) + 1;
+            size_t iLen = minipal_get_length_utf8_to_utf16(pPropName, cchPropName, 0);
             rProps[ix].pName = reinterpret_cast<WCHAR*>(sNames.Alloc(iLen*sizeof(WCHAR)));
-            MultiByteToWideChar(CP_UTF8, 0, pPropName, -1, rProps[ix].pName, iLen);
+            minipal_convert_utf8_to_utf16(pPropName, cchPropName, (CHAR16_T*)rProps[ix].pName, iLen, 0);
 
             // Check whether the property has a dispid attribute.
             hr = pMeth->GetMDImport()->GetDispIdOfMemberDef(pd, &dispid);
diff --git a/src/coreclr/vm/dllimport.cpp b/src/coreclr/vm/dllimport.cpp
index 66aaa273713651..efe4c7f4966ebd 100644
--- a/src/coreclr/vm/dllimport.cpp
+++ b/src/coreclr/vm/dllimport.cpp
@@ -5960,7 +5960,8 @@ namespace
             StackSString ssLibName(SString::Utf8, pMD->GetLibName());
 
             WCHAR wszEPName[50];
-            if (MultiByteToWideChar(CP_UTF8, 0, (LPCSTR)pMD->GetEntrypointName(), -1, wszEPName, sizeof(wszEPName)/sizeof(WCHAR)) == 0)
+            LPCSTR szEPName = (LPCSTR)pMD->GetEntrypointName();
+            if (minipal_convert_utf8_to_utf16(szEPName, strlen(szEPName) + 1, (CHAR16_T*)wszEPName, ARRAY_SIZE(wszEPName), 0) == 0)
             {
                 wszEPName[0] = W('?');
                 wszEPName[1] = W('\0');
diff --git a/src/coreclr/vm/dwbucketmanager.hpp b/src/coreclr/vm/dwbucketmanager.hpp
index 6576f6e0600984..d212a5b90ae3b9 100644
--- a/src/coreclr/vm/dwbucketmanager.hpp
+++ b/src/coreclr/vm/dwbucketmanager.hpp
@@ -545,12 +545,13 @@ void BaseBucketParamsManager::GetModuleName(_Out_writes_(maxLength) WCHAR* targe
         // Get the assembly name, and determine its length, including terminating NULL.
         Assembly* pAssembly = pModule->GetAssembly();
         LPCUTF8 utf8AssemblyName = pAssembly->GetSimpleName();
-        const int assemblyNameLength = MultiByteToWideChar(CP_UTF8, 0, utf8AssemblyName, -1, NULL, 0);
+        const size_t utf8AssemblyNameLength = strlen(utf8AssemblyName) + 1;
+        const size_t assemblyNameLength = minipal_get_length_utf8_to_utf16(utf8AssemblyName, utf8AssemblyNameLength, 0);
 
         // Allocate a buffer and convert assembly name - multi-module assemblies are no longer supported.
-        int fullNameLength = assemblyNameLength;
+        size_t fullNameLength = assemblyNameLength;
         WCHAR *fullName = reinterpret_cast< WCHAR* >(_alloca(sizeof(WCHAR)*(fullNameLength)));
-        MultiByteToWideChar(CP_UTF8, 0, utf8AssemblyName, -1, fullName, fullNameLength);
+        minipal_convert_utf8_to_utf16(utf8AssemblyName, utf8AssemblyNameLength, (CHAR16_T*)fullName, fullNameLength, 0);
 
         if (!failed)
         {
diff --git a/src/coreclr/vm/eventtrace_bulktype.cpp b/src/coreclr/vm/eventtrace_bulktype.cpp
index 146d706078f23c..d22760eed533a5 100644
--- a/src/coreclr/vm/eventtrace_bulktype.cpp
+++ b/src/coreclr/vm/eventtrace_bulktype.cpp
@@ -465,14 +465,14 @@ void BulkStaticsLogger::WriteEntry(AppDomain *domain, Object **address, Object *
     ULONGLONG th = (ULONGLONG)typeHandle.AsTAddr();
     ETW::TypeSystemLog::LogTypeAndParametersIfNecessary(m_typeLogger, th, ETW::TypeSystemLog::kTypeLogBehaviorTakeLockAndLogIfFirstTime);
 
-    // We should have at least 512 characters remaining in the buffer here.
+    // We should have room for an entry with the longest field name in the buffer here.
     int remaining = kMaxBytesValues - m_used;
-    _ASSERTE(kMaxBytesValues - m_used > 512);
+    _ASSERTE(remaining >= EventStaticEntry::MaxEntrySize());
 
     int len = EventStaticEntry::WriteEntry(m_buffer + m_used, remaining, (ULONGLONG)address,
                                            (ULONGLONG)obj, th, 0, fieldDesc);
 
-    // 512 bytes was not enough buffer?  This shouldn't happen, so we'll skip emitting the
+    // There was not enough buffer?  This shouldn't happen, so we'll skip emitting the
     // event on error.
     if (len > 0)
     {
@@ -481,7 +481,7 @@ void BulkStaticsLogger::WriteEntry(AppDomain *domain, Object **address, Object *
     }
 
     // When we are close to running out of buffer, emit the event.
-    if (kMaxBytesValues - m_used < 512)
+    if (kMaxBytesValues - m_used < EventStaticEntry::MaxEntrySize())
         FireBulkStaticsEvent();
 }
 
diff --git a/src/coreclr/vm/eventtracepriv.h b/src/coreclr/vm/eventtracepriv.h
index a1772c8a4fdef6..ea5504c80cb67b 100644
--- a/src/coreclr/vm/eventtracepriv.h
+++ b/src/coreclr/vm/eventtracepriv.h
@@ -104,6 +104,13 @@ struct EventStaticEntry
     ULONG Flags;
     WCHAR Name[0];
 
+    // The size of an entry with the longest field name we emit (255 characters).  Longer names are emitted as empty strings.
+    static int MaxEntrySize()
+    {
+        LIMITED_METHOD_CONTRACT;
+        return (int)(sizeof(EventStaticEntry) + 256 * sizeof(WCHAR));
+    }
+
     // Writes one EventStaticEntry to the buffer specified by ptr.  Since we don't actually know how large the event will be,
     // this write may fail if the remaining buffer is not large enough.  This function returns the number of bytes written
     // on success (return is >= 0), and -1 on failure.  If we return -1, the caller is expected to flush the current buffer
@@ -120,21 +127,20 @@ struct EventStaticEntry
 
         // The location in the structure to write to.  We won't actually write here unless we have sufficient buffer.
         WCHAR *name = (WCHAR *)(ptr + offsetof(EventStaticEntry, Name));
-        int len = 0;
+        size_t len = 0;
 
         LPCUTF8 utf8Name = 0;
         if (SUCCEEDED(fieldDesc->GetName_NoThrow(&utf8Name)))
         {
-            len = MultiByteToWideChar(CP_ACP, 0, utf8Name, -1, name, sizeRemaining - sizeof(EventStaticEntry));
-            if (len <= 0)
+            len = minipal_convert_utf8_to_utf16(utf8Name, strlen(utf8Name) + 1, (CHAR16_T*)name,
+                (sizeRemaining - sizeof(EventStaticEntry)) / sizeof(WCHAR), 0);
+            if (len == 0)
             {
-                // We will ignore corrupted/bad metadata here and only emit names for fields which are
-                // up to 255 characters (and also don't fit in the buffer).
-                if (GetLastError() == ERROR_INSUFFICIENT_BUFFER && sizeRemaining < 256)
+                // We will only emit names for fields which are up to 255 characters (and also don't fit in the buffer).
+                if (sizeRemaining < MaxEntrySize())
                     return -1; // nothing written, insufficient buffer.  Flush and try again.
 
-                // If the name is larger than 255 or we have some other error converting the string,
-                // just emit an empty string.
+                // If the name is larger than 255, just emit an empty string.
                 len = 1;
                 name[0] = 0;
             }
@@ -157,7 +163,7 @@ struct EventStaticEntry
         entry->TypeID = typeId;
         entry->Flags = flags;
 
-        return sizeof(EventStaticEntry) + len * sizeof(WCHAR);
+        return (int)(sizeof(EventStaticEntry) + len * sizeof(WCHAR));
     }
 };
 
diff --git a/src/coreclr/vm/gcenv.ee.cpp b/src/coreclr/vm/gcenv.ee.cpp
index 22f762a1d4ec52..75cc80ea378686 100644
--- a/src/coreclr/vm/gcenv.ee.cpp
+++ b/src/coreclr/vm/gcenv.ee.cpp
@@ -1285,7 +1285,7 @@ bool GCToEEInterface::GetBooleanConfigValue(const char* privateKey, const char*
     }
 
     WCHAR configKey[MaxConfigKeyLength];
-    if (MultiByteToWideChar(CP_ACP, 0, privateKey, -1 /* key is null-terminated */, configKey, MaxConfigKeyLength) == 0)
+    if (minipal_convert_utf8_to_utf16(privateKey, strlen(privateKey) + 1, (CHAR16_T*)configKey, MaxConfigKeyLength, 0) == 0)
     {
         // whatever this is... it's not something we care about. (It was too long, wasn't unicode, etc.)
         return false;
@@ -1300,7 +1300,7 @@ bool GCToEEInterface::GetBooleanConfigValue(const char* privateKey, const char*
     }
     else if (publicKey != NULL)
     {
-        if (MultiByteToWideChar(CP_ACP, 0, publicKey, -1 /* key is null-terminated */, configKey, MaxConfigKeyLength) == 0)
+        if (minipal_convert_utf8_to_utf16(publicKey, strlen(publicKey) + 1, (CHAR16_T*)configKey, MaxConfigKeyLength, 0) == 0)
         {
             // whatever this is... it's not something we care about. (It was too long, wasn't unicode, etc.)
             return false;
@@ -1335,7 +1335,7 @@ bool GCToEEInterface::GetIntConfigValue(const char* privateKey, const char* publ
     }
 
     WCHAR configKey[MaxConfigKeyLength];
-    if (MultiByteToWideChar(CP_ACP, 0, privateKey, -1 /* key is null-terminated */, configKey, MaxConfigKeyLength) == 0)
+    if (minipal_convert_utf8_to_utf16(privateKey, strlen(privateKey) + 1, (CHAR16_T*)configKey, MaxConfigKeyLength, 0) == 0)
     {
         // whatever this is... it's not something we care about. (It was too long, wasn't unicode, etc.)
         return false;
@@ -1372,7 +1372,7 @@ bool GCToEEInterface::GetIntConfigValue(const char* privateKey, const char* publ
     }
     else if (publicKey != NULL)
     {
-        if (MultiByteToWideChar(CP_ACP, 0, publicKey, -1 /* key is null-terminated */, configKey, MaxConfigKeyLength) == 0)
+        if (minipal_convert_utf8_to_utf16(publicKey, strlen(publicKey) + 1, (CHAR16_T*)configKey, MaxConfigKeyLength, 0) == 0)
         {
             // whatever this is... it's not something we care about. (It was too long, wasn't unicode, etc.)
             return false;
@@ -1395,7 +1395,7 @@ bool GCToEEInterface::GetStringConfigValue(const char* privateKey, const char* p
     } CONTRACTL_END;
 
     WCHAR configKey[MaxConfigKeyLength];
-    if (MultiByteToWideChar(CP_ACP, 0, privateKey, -1 /* key is null-terminated */, configKey, MaxConfigKeyLength) == 0)
+    if (minipal_convert_utf8_to_utf16(privateKey, strlen(privateKey) + 1, (CHAR16_T*)configKey, MaxConfigKeyLength, 0) == 0)
     {
         // whatever this is... it's not something we care about. (It was too long, wasn't unicode, etc.)
         return false;
@@ -1408,20 +1408,22 @@ bool GCToEEInterface::GetStringConfigValue(const char* privateKey, const char* p
     {
         if (publicKey != NULL)
         {
-            if (MultiByteToWideChar(CP_ACP, 0, publicKey, -1 /* key is null-terminated */, configKey, MaxConfigKeyLength) == 0)
+            if (minipal_convert_utf8_to_utf16(publicKey, strlen(publicKey) + 1, (CHAR16_T*)configKey, MaxConfigKeyLength, 0) == 0)
             {
                 // whatever this is... it's not something we care about. (It was too long, wasn't unicode, etc.)
                 return false;
             }
             out =  Configuration::GetKnobStringValue(configKey);
-            if (out == NULL)
-            {
-                return false;
-            }
         }
     }
 
-    int charCount = WideCharToMultiByte(CP_ACP, 0, out, -1 /* out is null-terminated */, NULL, 0, nullptr, nullptr);
+    if (out == NULL)
+    {
+        return false;
+    }
+
+    size_t cchOut = u16_strlen(out) + 1;
+    size_t charCount = minipal_get_length_utf16_to_utf8((const CHAR16_T*)out, cchOut, 0);
     if (charCount == 0)
     {
         // this should only happen if the config subsystem gives us a string that's not valid
@@ -1444,10 +1446,9 @@ bool GCToEEInterface::GetStringConfigValue(const char* privateKey, const char* p
         return false;
     }
 
-    if (WideCharToMultiByte(CP_ACP, 0, out, -1 /* out is null-terminated */,
-          configResult, charCount, nullptr, nullptr) == 0)
+    if (minipal_convert_utf16_to_utf8((const CHAR16_T*)out, cchOut, configResult, charCount, 0) == 0)
     {
-        // this should never happen, the previous call to WideCharToMultiByte that computed the charCount should
+        // this should never happen, the previous call that computed the charCount should
         // have caught all issues.
         assert(false);
         if (fromClrConfig)
diff --git a/src/coreclr/vm/gctoclreventsink.cpp b/src/coreclr/vm/gctoclreventsink.cpp
index 13e35e861223c9..446441bc07fcb2 100644
--- a/src/coreclr/vm/gctoclreventsink.cpp
+++ b/src/coreclr/vm/gctoclreventsink.cpp
@@ -14,7 +14,7 @@ void GCToCLREventSink::FireDynamicEvent(const char* eventName, void* payload, ui
     const size_t EventNameMaxSize = 255;
 
     WCHAR wideEventName[EventNameMaxSize];
-    if (MultiByteToWideChar(CP_ACP, 0, eventName, -1, wideEventName, EventNameMaxSize) == 0)
+    if (minipal_convert_utf8_to_utf16(eventName, strlen(eventName) + 1, (CHAR16_T*)wideEventName, EventNameMaxSize, 0) == 0)
     {
         return;
     }
diff --git a/src/coreclr/vm/gdbjit.cpp b/src/coreclr/vm/gdbjit.cpp
index abc16988b468f0..e456402e853e6b 100644
--- a/src/coreclr/vm/gdbjit.cpp
+++ b/src/coreclr/vm/gdbjit.cpp
@@ -522,11 +522,12 @@ GetDebugInfoFromPDB(MethodDesc* methodDescPtr,
 
     for (int i = 0; i < locals.size; i++)
     {
-        size_t sizeRequired = WideCharToMultiByte(CP_UTF8, 0, methodDebugInfo.locals[i].name, -1, NULL, 0, NULL, NULL);
+        const CHAR16_T* localName = (const CHAR16_T*)methodDebugInfo.locals[i].name;
+        size_t cchLocalName = u16_strlen(methodDebugInfo.locals[i].name) + 1;
+        size_t sizeRequired = minipal_get_length_utf16_to_utf8(localName, cchLocalName, 0);
         locals.localsName[i] = new char[sizeRequired];
 
-        int len = WideCharToMultiByte(
-            CP_UTF8, 0, methodDebugInfo.locals[i].name, -1, locals.localsName[i], sizeRequired, NULL, NULL);
+        minipal_convert_utf16_to_utf8(localName, cchLocalName, locals.localsName[i], sizeRequired, 0);
         locals.localsScope[i].ilStartOffset = methodDebugInfo.locals[i].startOffset;
         locals.localsScope[i].ilEndOffset = methodDebugInfo.locals[i].endOffset;
     }
@@ -554,7 +555,7 @@ GetDebugInfoFromPDB(MethodDesc* methodDescPtr,
             if ((ULONG)(methodDebugInfo.points[i].ilOffset) == map[j].ilOffset)
             {
                 s.fileIndex = 0;
-                int len = WideCharToMultiByte(CP_UTF8, 0, sp.fileName, -1, s.fileName, sizeof(s.fileName), NULL, NULL);
+                size_t len = minipal_convert_utf16_to_utf8((const CHAR16_T*)sp.fileName, u16_strlen(sp.fileName), s.fileName, sizeof(s.fileName) - 1, 0);
                 s.fileName[len] = 0;
                 s.lineNumber = sp.lineNumber;
                 break;
@@ -2511,11 +2512,12 @@ void NotifyGdb::OnMethodPrepared(MethodDesc* methodDescPtr, PCODE pCode, const C
     const char* szModName = modName.GetUTF8();
     const char* szModuleFile = SplitFilename(szModName);
 
-    int length = MultiByteToWideChar(CP_UTF8, 0, szModuleFile, -1, NULL, 0);
+    size_t cchModuleFile = strlen(szModuleFile) + 1;
+    size_t length = minipal_get_length_utf8_to_utf16(szModuleFile, cchModuleFile, 0);
     if (length == 0)
         return;
     WStringHolder wszModuleFile(new WCHAR[length+1]);
-    length = MultiByteToWideChar(CP_UTF8, 0, szModuleFile, -1, wszModuleFile, length);
+    length = minipal_convert_utf8_to_utf16(szModuleFile, cchModuleFile, (CHAR16_T*)(WCHAR*)wszModuleFile, length, 0);
 
     if (length == 0)
         return;
diff --git a/src/coreclr/vm/interoputil.cpp b/src/coreclr/vm/interoputil.cpp
index 6c1a4dbb61242d..9e96bf28f006aa 100644
--- a/src/coreclr/vm/interoputil.cpp
+++ b/src/coreclr/vm/interoputil.cpp
@@ -606,7 +606,7 @@ HRESULT GetStringizedTypeLibGuidForAssembly(Assembly *pAssembly, CQuickArray<BYT
     LPCUTF8     pszName = NULL;         // Library name in UTF8.
     ULONG       cbName;                 // Length of name, UTF8 characters.
     LPWSTR      pName;                  // Pointer to library name.
-    ULONG       cchName;                // Length of name, wide chars.
+    size_t      cchName;                // Length of name, wide chars.
     LPWSTR      pch=0;                  // Pointer into lib name.
     const void  *pSN=NULL;              // Pointer to public key.
     DWORD       cbSN=0;                 // Size of public key.
@@ -621,7 +621,12 @@ HRESULT GetStringizedTypeLibGuidForAssembly(Assembly *pAssembly, CQuickArray<BYT
     // Get the name, and determine its length.
     pszName = pAssembly->GetSimpleName();
     cbName=(ULONG)strlen(pszName);
+#ifdef TARGET_WINDOWS
+    // The GUID is generated from the converted name, so the conversion must not change
     cchName = MultiByteToWideChar(CP_ACP,0, pszName,cbName+1, 0,0);
+#else
+    cchName = minipal_get_length_utf8_to_utf16(pszName, cbName+1, 0);
+#endif
 
     // See if there is a public key.
     EX_TRY
@@ -686,7 +691,11 @@ HRESULT GetStringizedTypeLibGuidForAssembly(Assembly *pAssembly, CQuickArray<BYT
     IfFailGo(rDef.ReSizeNoThrow(cbCur + cchName*sizeof(WCHAR) + sizeof(szTypeLibKeyName)-1 + cbSN + sizeof(ver)+sizeof(USHORT)));
 
     // Put it all together.  Name first.
-    MultiByteToWideChar(CP_ACP,0, pszName,cbName+1, (LPWSTR)(&rDef[cbCur]),cchName);
+#ifdef TARGET_WINDOWS
+    MultiByteToWideChar(CP_ACP,0, pszName,cbName+1, (LPWSTR)(&rDef[cbCur]), (int)cchName);
+#else
+    minipal_convert_utf8_to_utf16(pszName, cbName+1, (CHAR16_T*)(&rDef[cbCur]), cchName, 0);
+#endif
     pName = (LPWSTR)(&rDef[cbCur]);
     for (pch=pName; *pch; ++pch)
         if (*pch == '.' || *pch == ' ')
@@ -694,7 +703,7 @@ HRESULT GetStringizedTypeLibGuidForAssembly(Assembly *pAssembly, CQuickArray<BYT
     else
         if (iswupper(*pch))
             *pch = towlower(*pch);
-    cbCur += (cchName-1)*sizeof(WCHAR);
+    cbCur += (ULONG)((cchName - 1) * sizeof(WCHAR));
     memcpy(&rDef[cbCur], szTypeLibKeyName, sizeof(szTypeLibKeyName)-1);
     cbCur += sizeof(szTypeLibKeyName)-1;
 
diff --git a/src/coreclr/vm/object.cpp b/src/coreclr/vm/object.cpp
index 27eb9ba75b409f..77966a09ecbc93 100644
--- a/src/coreclr/vm/object.cpp
+++ b/src/coreclr/vm/object.cpp
@@ -676,17 +676,23 @@ STRINGREF StringObject::NewString(LPCUTF8 psz)
         PRECONDITION(CheckPointer(psz));
     } CONTRACTL_END;
 
-    int length = (int)strlen(psz);
+    size_t length = strlen(psz);
     if (length == 0) {
         return GetEmptyString();
     }
     CQuickBytes qb;
-    WCHAR* pwsz = (WCHAR*) qb.AllocThrows((length) * sizeof(WCHAR));
-    length = MultiByteToWideChar(CP_UTF8, 0, psz, length, pwsz, length);
+    S_SIZE_T cWszBytes = S_SIZE_T(length) * S_SIZE_T(sizeof(WCHAR));
+    if (cWszBytes.IsOverflow())
+        COMPlusThrowOM();
+    WCHAR* pwsz = (WCHAR*) qb.AllocThrows(cWszBytes.Value());
+    length = minipal_convert_utf8_to_utf16(psz, length, (CHAR16_T*)pwsz, length, 0);
     if (length == 0) {
         COMPlusThrow(kArgumentException, W("Arg_InvalidUTF8String"));
     }
-    return NewString(pwsz, length);
+    if (length > INT_MAX) {
+        COMPlusThrowOM();
+    }
+    return NewString(pwsz, (int)length);
 }
 
 STRINGREF StringObject::NewString(LPCUTF8 psz, int cBytes)
@@ -706,16 +712,19 @@ STRINGREF StringObject::NewString(LPCUTF8 psz, int cBytes)
     if (cBytes == 0) {
         return GetEmptyString();
     }
-    int cWszBytes = 0;
-    if (!ClrSafeInt<int>::multiply(cBytes, sizeof(WCHAR), cWszBytes))
+    S_SIZE_T cWszBytes = S_SIZE_T(cBytes) * S_SIZE_T(sizeof(WCHAR));
+    if (cWszBytes.IsOverflow())
         COMPlusThrowOM();
     CQuickBytes qb;
-    WCHAR* pwsz = (WCHAR*) qb.AllocThrows(cWszBytes);
-    int length = MultiByteToWideChar(CP_UTF8, 0, psz, cBytes, pwsz, cBytes);
+    WCHAR* pwsz = (WCHAR*) qb.AllocThrows(cWszBytes.Value());
+    size_t length = minipal_convert_utf8_to_utf16(psz, cBytes, (CHAR16_T*)pwsz, cBytes, 0);
     if (length == 0) {
         COMPlusThrow(kArgumentException, W("Arg_InvalidUTF8String"));
     }
-    return NewString(pwsz, length);
+    if (length > INT_MAX) {
+        COMPlusThrowOM();
+    }
+    return NewString(pwsz, (int)length);
 }
 
 //
diff --git a/src/coreclr/vm/util.cpp b/src/coreclr/vm/util.cpp
index f429dea34d7ce4..631ee85a365d78 100644
--- a/src/coreclr/vm/util.cpp
+++ b/src/coreclr/vm/util.cpp
@@ -135,6 +135,7 @@ void PrintToStdErrW(const WCHAR *pwzString)
     }
     CONTRACTL_END
 
+#ifdef TARGET_WINDOWS
     UINT codePage = GetConsoleOutputCP();
     // Console output allows best-fit mapping and default-character substitution.
     int byteCount = WideCharToMultiByte(codePage, 0, pwzString, -1, nullptr, 0, nullptr, nullptr);
@@ -149,6 +150,14 @@ void PrintToStdErrW(const WCHAR *pwzString)
     {
         ThrowWin32(ERROR_NO_UNICODE_TRANSLATION);
     }
+#else
+    size_t cchString = u16_strlen(pwzString) + 1;
+    size_t byteCount = minipal_get_length_utf16_to_utf8((const CHAR16_T*)pwzString, cchString, 0);
+
+    CQuickBytes buffer;
+    char* pStr = static_cast<char*>(buffer.AllocThrows(byteCount));
+    minipal_convert_utf16_to_utf8((const CHAR16_T*)pwzString, cchString, pStr, byteCount, 0);
+#endif
 
     PrintToStdErrA(pStr);
 }
diff --git a/src/native/minipal/utf8.h b/src/native/minipal/utf8.h
index 009f0f0c1712a9..c074eda26685f8 100644
--- a/src/native/minipal/utf8.h
+++ b/src/native/minipal/utf8.h
@@ -24,7 +24,8 @@ extern "C"
  * @param source The source string in UTF-8 format.
  * @param sourceLength Length of the source string.
  * @param flags Flags to alter the behavior of converter. Supported flags are MINIPAL_MB_NO_REPLACE_INVALID_CHARS and MINIPAL_TREAT_AS_LITTLE_ENDIAN.
- * @return Length of UTF-16 buffer required by the conversion.
+ * @return Length of UTF-16 buffer required by the conversion, or 0 with errno set to MINIPAL_ERROR_NO_UNICODE_TRANSLATION
+ *         if MINIPAL_MB_NO_REPLACE_INVALID_CHARS is set and the source has an ill-formed sequence.
  */
 size_t minipal_get_length_utf8_to_utf16(const char* source, size_t sourceLength, unsigned int flags);
 
@@ -43,10 +44,11 @@ size_t minipal_get_length_utf16_to_utf8(const CHAR16_T* source, size_t sourceLen
  *
  * @param source The source string in UTF-8 format.
  * @param sourceLength Length of the source string.
- * @param destination Pointer to the destination UTF-16 string. It can be NULL to query number of items required by the conversion.
+ * @param destination Pointer to the destination UTF-16 string. Use minipal_get_length_utf8_to_utf16 for the number of items required.
  * @param destinationLength Length of the destination string.
  * @param flags Flags to alter the behavior of converter. Supported flags are MINIPAL_MB_NO_REPLACE_INVALID_CHARS and MINIPAL_TREAT_AS_LITTLE_ENDIAN.
- * @return Number of items written by the conversion.
+ * @return Number of items written by the conversion, or 0 with errno set to MINIPAL_ERROR_INSUFFICIENT_BUFFER or
+ *         MINIPAL_ERROR_NO_UNICODE_TRANSLATION if it fails. errno is 0 when the conversion succeeds.
  */
 size_t minipal_convert_utf8_to_utf16(const char* source, size_t sourceLength, CHAR16_T* destination, size_t destinationLength, unsigned int flags);
 
@@ -55,10 +57,11 @@ size_t minipal_convert_utf8_to_utf16(const char* source, size_t sourceLength, CH
  *
  * @param source The source string in UTF-16 format.
  * @param sourceLength Length of the source string.
- * @param destination Pointer to the destination UTF-8 string. It can be NULL to query number of items required by the conversion.
+ * @param destination Pointer to the destination UTF-8 string. Use minipal_get_length_utf16_to_utf8 for the number of items required.
  * @param destinationLength Length of the destination string.
  * @param flags Flags to alter the behavior of converter. Supported flags are MINIPAL_MB_NO_REPLACE_INVALID_CHARS and MINIPAL_TREAT_AS_LITTLE_ENDIAN.
- * @return Number of items written by the conversion.
+ * @return Number of items written by the conversion, or 0 with errno set to MINIPAL_ERROR_INSUFFICIENT_BUFFER if it fails.
+ *         errno is 0 when the conversion succeeds.
  */
 size_t minipal_convert_utf16_to_utf8(const CHAR16_T* source, size_t sourceLength, char* destination, size_t destinationLength, unsigned int flags);
 
diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index a0c26e25719cd2..e5a148ddfb4c56 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -7,7 +7,7 @@ include(${CLR_ENG_NATIVE_DIR}/configurecompiler.cmake)
 
 include_directories("${CLR_SRC_NATIVE_DIR}")
 
-add_subdirectory(${CLR_SRC_NATIVE_DIR}/minipal minipal)
+add_subdirectory(${CLR_SRC_NATIVE_DIR}/minipal shared_minipal)
 list(APPEND LINK_LIBRARIES_ADDITIONAL PRIVATE minipal)
 
 # Add this subdir. We install the headers for the jit.
diff --git a/src/tests/minipal/CMakeLists.txt b/src/tests/minipal/CMakeLists.txt
new file mode 100644
index 00000000000000..445487d2000ce8
--- /dev/null
+++ b/src/tests/minipal/CMakeLists.txt
@@ -0,0 +1,20 @@
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+
+if(CLR_CMAKE_TARGET_ANDROID OR CLR_CMAKE_TARGET_IOS OR CLR_CMAKE_TARGET_TVOS OR CLR_CMAKE_TARGET_MACCATALYST OR CLR_CMAKE_TARGET_ARCH_WASM)
+    return()
+endif()
+
+include_directories(${CLR_SRC_NATIVE_DIR})
+
+set(NATIVE_TEST_COMMON_DIR ../tracing/eventpipe/native/common)
+
+add_executable(NativeMinipalTestsDriver
+    ${NATIVE_TEST_COMMON_DIR}/driver.c
+    ${NATIVE_TEST_COMMON_DIR}/test.c
+    native-minipal-tests-driver.c
+    utf8-tests.c)
+
+target_include_directories(NativeMinipalTestsDriver PRIVATE ${NATIVE_TEST_COMMON_DIR})
+target_link_libraries(NativeMinipalTestsDriver PRIVATE minipal)
+install(TARGETS NativeMinipalTestsDriver DESTINATION bin)
diff --git a/src/tests/minipal/Directory.Build.props b/src/tests/minipal/Directory.Build.props
new file mode 100644
index 00000000000000..6fac0339d0408f
--- /dev/null
+++ b/src/tests/minipal/Directory.Build.props
@@ -0,0 +1,4 @@
+<Project>
+  <!-- The minipal tests use the native test driver of the EventPipe and container tests. -->
+  <Import Project="$(MSBuildThisFileDirectory)..\tracing\eventpipe\native\Directory.Build.props" />
+</Project>
diff --git a/src/tests/minipal/Directory.Build.targets b/src/tests/minipal/Directory.Build.targets
new file mode 100644
index 00000000000000..8baf73e3ee0ea1
--- /dev/null
+++ b/src/tests/minipal/Directory.Build.targets
@@ -0,0 +1,4 @@
+<Project>
+  <!-- The minipal tests use the native test driver of the EventPipe and container tests. -->
+  <Import Project="$(MSBuildThisFileDirectory)..\tracing\eventpipe\native\Directory.Build.targets" />
+</Project>
diff --git a/src/tests/minipal/NativeMinipalTests.cs b/src/tests/minipal/NativeMinipalTests.cs
new file mode 100644
index 00000000000000..23a678bad86c18
--- /dev/null
+++ b/src/tests/minipal/NativeMinipalTests.cs
@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using Xunit;
+
+public class NativeMinipalTests
+{
+    [Theory]
+    [InlineData("utf8")]
+    public static void RunSuite(string group)
+    {
+        (int exitCode, string output, string error) = NativeTestProcess.Run("NativeMinipalTestsDriver", group);
+        Console.Write(output);
+        Console.Error.Write(error);
+        Assert.Equal(0, exitCode);
+    }
+}
diff --git a/src/tests/minipal/NativeMinipalTests.csproj b/src/tests/minipal/NativeMinipalTests.csproj
new file mode 100644
index 00000000000000..03acd75ea79f36
--- /dev/null
+++ b/src/tests/minipal/NativeMinipalTests.csproj
@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <Compile Include="NativeMinipalTests.cs" />
+    <CMakeProjectReference Include="CMakeLists.txt" />
+    <ProjectReference Include="$(TestLibraryProjectPath)" />
+  </ItemGroup>
+</Project>
diff --git a/src/tests/minipal/native-minipal-tests-driver.c b/src/tests/minipal/native-minipal-tests-driver.c
new file mode 100644
index 00000000000000..59899dba334103
--- /dev/null
+++ b/src/tests/minipal/native-minipal-tests-driver.c
@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#include "test.h"
+
+DEFINE_TEST_GROUP_INIT_H(minipal_utf8_tests_init);
+
+static const Group test_groups[] = {
+    {"utf8", minipal_utf8_tests_init},
+    {NULL, NULL}
+};
+
+int DN_CALLBACK_CALLTYPE main(int argc, char **argv)
+{
+    return run_tests_main(test_groups, argc, argv);
+}
diff --git a/src/tests/minipal/utf8-tests.c b/src/tests/minipal/utf8-tests.c
new file mode 100644
index 00000000000000..49b2aad3ade1d2
--- /dev/null
+++ b/src/tests/minipal/utf8-tests.c
@@ -0,0 +1,1049 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#include "test.h"
+
+#include <errno.h>
+#include <stdint.h>
+#include <minipal/utf8.h>
+
+#define W(str) ((const CHAR16_T*)u##str)
+
+#define CHECK(call) do { RESULT check_result = (call); if (check_result != OK) return check_result; } while (0)
+
+// A value the conversions never set, to see that they clear errno when they succeed
+#define ERRNO_SENTINEL 12345
+
+#define REPLACEMENT_CHAR 0xFFFD
+
+static const CHAR16_T Utf16Canary = 0xBEEF;
+static const char Utf8Canary = '\xA5';
+
+typedef struct
+{
+    const char* utf8;
+    const CHAR16_T* utf16;
+} StringPair;
+
+typedef struct
+{
+    const char* utf8;
+    size_t utf8Length;
+    const CHAR16_T* utf16;
+    size_t utf16Length;
+} CountedStringPair;
+
+// Strings that convert both ways
+static const StringPair valid_strings[] =
+{
+    // Empty string
+    { "", W("") },
+    // 1, 2 and 3 byte encoded 1 character long strings
+    { "A", W("A") },
+    { "\xC2\x80", W("\x0080") },
+    { "\xE0\xA0\x80", W("\x0800") },
+    // 1 byte encoded characters only
+    { "ABCDEFGHIJKLMNOPQRSTUVWXYZ", W("ABCDEFGHIJKLMNOPQRSTUVWXYZ") },
+    // 2 byte encoded characters only
+    { "\xC2\x80\xC3\xBF\xC7\x81\xDF\xBF", W("\x0080\x00FF\x01C1\x07FF") },
+    // 3 byte encoded characters only
+    { "\xE0\xA0\x80\xE1\xB6\x88\xE1\x80\x80\xEF\xBF\xBF", W("\x0800\x1D88\x1000\xFFFF") },
+    // 1 and 2 byte encoded characters interleaved 1:1, starting and ending with either
+    { "\x41\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF\x45", W("\x0041\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF\x0045") },
+    { "\x41\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF", W("\x0041\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF") },
+    { "\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF\x45", W("\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF\x0045") },
+    { "\xC2\x80\x42\xC3\xBF\x43\xC7\x81\x44\xDF\xBF", W("\x0080\x0042\x00FF\x0043\x01C1\x0044\x07FF") },
+    // 1 and 2 byte encoded characters interleaved 2:2, starting and ending with either
+    { "\x41\x42\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF\x45\x46", W("\x0041\x0042\x0080\x00FF\x0043\x0044\x01C1\x07FF\x0045\x0046") },
+    { "\x41\x42\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF", W("\x0041\x0042\x0080\x00FF\x0043\x0044\x01C1\x07FF") },
+    { "\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF\x45\x46", W("\x0080\x00FF\x0043\x0044\x01C1\x07FF\x0045\x0046") },
+    { "\xC2\x80\xC3\xBF\x43\x44\xC7\x81\xDF\xBF", W("\x0080\x00FF\x0043\x0044\x01C1\x07FF") },
+    // 4 byte encoded characters, which are surrogate pairs in UTF-16
+    { "\xF0\x90\x80\x80\xF0\x90\x89\x80\xF3\x80\x8E\xB0\xF4\x8F\xBF\xBF", W("\xD800\xDC00\xD800\xDE40\xDAC0\xDFB0\xDBFF\xDFFF") },
+};
+
+// Ill-formed UTF-8 and the UTF-16 it converts to
+static const StringPair invalid_utf8_strings[] =
+{
+    // Incomplete 2, 3 and 4 byte encoded characters standalone
+    { "\xC2", W("\xFFFD") },
+    { "\xE0\xA0", W("\xFFFD") },
+    { "\xE0", W("\xFFFD") },
+    { "\xF0\x90\x80", W("\xFFFD") },
+    { "\xF0\x90", W("\xFFFD") },
+    { "\xF0", W("\xFFFD") },
+    // Continuation byte with no lead byte standalone
+    { "\x80", W("\xFFFD") },
+    // The same between, before and after 1 byte encoded characters
+    { "\x41\xC2\x42", W("\x0041\xFFFD\x0042") },
+    { "\x41\xE0\xA0\x42", W("\x0041\xFFFD\x0042") },
+    { "\x41\xE0\x42", W("\x0041\xFFFD\x0042") },
+    { "\x41\x80\x42", W("\x0041\xFFFD\x0042") },
+    { "\xC2\x42", W("\xFFFD\x0042") },
+    { "\xE0\xA0\x42", W("\xFFFD\x0042") },
+    { "\xE0\x42", W("\xFFFD\x0042") },
+    { "\x80\x42", W("\xFFFD\x0042") },
+    { "\x41\xC2", W("\x0041\xFFFD") },
+    { "\x41\xE0\xA0", W("\x0041\xFFFD") },
+    { "\x41\xE0", W("\x0041\xFFFD") },
+    { "\x41\x80", W("\x0041\xFFFD") },
+    // ... and between 2 byte encoded characters
+    { "\xC2\x80\xC2\xC3\xBF", W("\x0080\xFFFD\x00FF") },
+    { "\xC2\x80\xE0\xA0\xC3\xBF", W("\x0080\xFFFD\x00FF") },
+    { "\xC2\x80\xE0\xC3\xBF", W("\x0080\xFFFD\x00FF") },
+    { "\xC2\x80\x80\xC3\xBF", W("\x0080\xFFFD\x00FF") },
+    // Non-shortest form encodings
+    { "\xC0\x80", W("\xFFFD\xFFFD") },
+    { "\xE0\x80\x80", W("\xFFFD\xFFFD") },
+    { "\xF0\x80\x80\x80", W("\xFFFD\xFFFD\xFFFD") },
+    // ... of the largest character of each shorter form
+    { "\xC1\xBF", W("\xFFFD\xFFFD") },
+    { "\xE0\x9F\xBF", W("\xFFFD\xFFFD") },
+    { "\xF0\x8F\xBF\xBF", W("\xFFFD\xFFFD\xFFFD") },
+    // Encoded high and low surrogates, a pair of them (CESU-8), and one between 1 byte encoded characters
+    { "\xED\xA0\x80", W("\xFFFD\xFFFD") },
+    { "\xED\xBF\xBF", W("\xFFFD\xFFFD") },
+    { "\xED\xA0\x80\xED\xB0\x80", W("\xFFFD\xFFFD\xFFFD\xFFFD") },
+    { "\x41\xED\xBF\xBF\x42", W("\x0041\xFFFD\xFFFD\x0042") },
+    // 4 byte encoded character above U+10FFFF, and lead bytes that can only encode such characters
+    { "\xF4\x90\x80\x80", W("\xFFFD\xFFFD\xFFFD") },
+    { "\xF5\x80\x80\x80", W("\xFFFD\xFFFD\xFFFD\xFFFD") },
+    { "\xF7\xBF\xBF\xBF", W("\xFFFD\xFFFD\xFFFD\xFFFD") },
+    // 5 and 6 byte encodings
+    { "\xF8\x88\x80\x80\x80", W("\xFFFD\xFFFD\xFFFD\xFFFD\xFFFD") },
+    { "\xFC\x84\x80\x80\x80\x80", W("\xFFFD\xFFFD\xFFFD\xFFFD\xFFFD\xFFFD") },
+    // Bytes that never appear in UTF-8
+    { "\xFE", W("\xFFFD") },
+    { "\xFF", W("\xFFFD") },
+    { "\x41\xFE\x42\xFF\x43", W("\x0041\xFFFD\x0042\xFFFD\x0043") },
+};
+
+// Ill-formed UTF-16 and the UTF-8 it converts to
+static const StringPair invalid_utf16_strings[] =
+{
+    // Lone high and low surrogates standalone, after a character and between two characters
+    { "\xEF\xBF\xBD", W("\xD800") },
+    { "\xEF\xBF\xBD", W("\xDC00") },
+    { "\x41\xEF\xBF\xBD", W("\x0041\xD800") },
+    { "\x41\xEF\xBF\xBD", W("\x0041\xDC00") },
+    { "\x41\xEF\xBF\xBD\x42", W("\x0041\xD800\x0042") },
+    { "\x41\xEF\xBF\xBD\x42", W("\x0041\xDC00\x0042") },
+    // Low surrogate followed by high surrogate, standalone and between two characters
+    { "\xEF\xBF\xBD\xEF\xBF\xBD", W("\xDC00\xD800") },
+    { "\x41\xEF\xBF\xBD\xEF\xBF\xBD\x42", W("\x0041\xDC00\xD800\x0042") },
+    // High surrogate followed by a surrogate pair, and a surrogate pair followed by a low surrogate
+    { "\xEF\xBF\xBD\xF0\x90\x80\x80", W("\xD800\xD800\xDC00") },
+    { "\xF0\x90\x80\x80\xEF\xBF\xBD", W("\xD800\xDC00\xDC00") },
+};
+
+// Explicit lengths that include NULs, which convert like any other character
+static const CountedStringPair utf8_strings_with_nuls[] =
+{
+    { "\0", 1, W("\0"), 1 },
+    { "\0\0", 2, W("\0\0"), 2 },
+    { "a\0b", 3, W("a\0b"), 3 },
+    // Incomplete 2 byte encoded character before a NUL, and a continuation byte after it
+    { "\xC2\0\x80", 3, W("\xFFFD\0\xFFFD"), 3 },
+    // Incomplete 2 byte encoded character at the end, after a NUL
+    { "a\0\xC2", 3, W("a\0\xFFFD"), 3 },
+    // 4 byte encoded character interrupted by a NUL, and one after a NUL
+    { "\xF0\x90\0\x80\x80", 5, W("\xFFFD\0\xFFFD\xFFFD"), 4 },
+    { "A\0\xF0\x90\x80\x80", 6, W("A\0\xD800\xDC00"), 4 },
+};
+
+static const CountedStringPair utf16_strings_with_nuls[] =
+{
+    { "\0", 1, W("\0"), 1 },
+    { "a\0b", 3, W("a\0b"), 3 },
+    // Surrogate pair interrupted by a NUL, and one after a NUL
+    { "\xEF\xBF\xBD\0\xEF\xBF\xBD", 7, W("\xD800\0\xDC00"), 3 },
+    { "\0\xF0\x9F\x98\x80", 5, W("\0\xD83D\xDE00"), 3 },
+    // High surrogate before a NUL at the end
+    { "\xEF\xBF\xBD\0", 4, W("\xD800\0"), 2 },
+};
+
+static bool is_big_endian(void)
+{
+    const uint16_t one = 1;
+    return *(const uint8_t*)&one == 0;
+}
+
+static CHAR16_T swap_bytes(CHAR16_T c)
+{
+    return (CHAR16_T)((c << 8) | (c >> 8));
+}
+
+static size_t utf16_length(const CHAR16_T* s)
+{
+    size_t length = 0;
+    while (s[length] != 0)
+        length++;
+    return length;
+}
+
+static bool has_replacement_char(const CHAR16_T* s, size_t length)
+{
+    for (size_t i = 0; i < length; i++)
+    {
+        if (s[i] == REPLACEMENT_CHAR)
+            return true;
+    }
+    return false;
+}
+
+static void fill_utf16(CHAR16_T* buffer, size_t length)
+{
+    for (size_t i = 0; i < length; i++)
+        buffer[i] = Utf16Canary;
+}
+
+static bool is_high_surrogate(uint32_t c)
+{
+    return c >= 0xD800 && c <= 0xDBFF;
+}
+
+static bool is_low_surrogate(uint32_t c)
+{
+    return c >= 0xDC00 && c <= 0xDFFF;
+}
+
+// A character at a time model of the conversions, which the optimized paths must agree with
+
+static size_t reference_encode_utf8(uint32_t codePoint, unsigned char* p)
+{
+    if (codePoint < 0x80)
+    {
+        p[0] = (unsigned char)codePoint;
+        return 1;
+    }
+    if (codePoint < 0x800)
+    {
+        p[0] = (unsigned char)(0xC0 | (codePoint >> 6));
+        p[1] = (unsigned char)(0x80 | (codePoint & 0x3F));
+        return 2;
+    }
+    if (codePoint < 0x10000)
+    {
+        p[0] = (unsigned char)(0xE0 | (codePoint >> 12));
+        p[1] = (unsigned char)(0x80 | ((codePoint >> 6) & 0x3F));
+        p[2] = (unsigned char)(0x80 | (codePoint & 0x3F));
+        return 3;
+    }
+    p[0] = (unsigned char)(0xF0 | (codePoint >> 18));
+    p[1] = (unsigned char)(0x80 | ((codePoint >> 12) & 0x3F));
+    p[2] = (unsigned char)(0x80 | ((codePoint >> 6) & 0x3F));
+    p[3] = (unsigned char)(0x80 | (codePoint & 0x3F));
+    return 4;
+}
+
+// Decodes one sequence and returns its length in bytes. An ill-formed sequence decodes to -1, and is an invalid lead
+// byte, a lead byte with an out of range second byte, or a lead byte with the continuation bytes that follow it before
+// the input ends or a byte that isn't a continuation byte. The ranges are the well-formed sequences of the Unicode
+// standard (Table 3-7).
+static size_t reference_decode_utf8(const unsigned char* p, size_t available, int32_t* codePoint)
+{
+    static const struct
+    {
+        unsigned char firstLead;
+        unsigned char lastLead;
+        unsigned char length;
+        unsigned char secondLow;
+        unsigned char secondHigh;
+    } sequences[] =
+    {
+        { 0x00, 0x7F, 1, 0, 0 },
+        { 0xC2, 0xDF, 2, 0x80, 0xBF },
+        { 0xE0, 0xE0, 3, 0xA0, 0xBF },
+        { 0xE1, 0xEC, 3, 0x80, 0xBF },
+        { 0xED, 0xED, 3, 0x80, 0x9F },
+        { 0xEE, 0xEF, 3, 0x80, 0xBF },
+        { 0xF0, 0xF0, 4, 0x90, 0xBF },
+        { 0xF1, 0xF3, 4, 0x80, 0xBF },
+        { 0xF4, 0xF4, 4, 0x80, 0x8F },
+    };
+
+    for (size_t i = 0; i < ARRAY_SIZE(sequences); i++)
+    {
+        if (p[0] < sequences[i].firstLead || p[0] > sequences[i].lastLead)
+            continue;
+
+        int32_t value = sequences[i].length == 1 ? p[0] : p[0] & (0x7F >> sequences[i].length);
+        for (size_t j = 1; j < sequences[i].length; j++)
+        {
+            if (j >= available || (p[j] & 0xC0) != 0x80)
+            {
+                *codePoint = -1;
+                return j;
+            }
+
+            if (j == 1 && (p[1] < sequences[i].secondLow || p[1] > sequences[i].secondHigh))
+            {
+                *codePoint = -1;
+                return 2;
+            }
+
+            value = (value << 6) | (p[j] & 0x3F);
+        }
+
+        *codePoint = value;
+        return sequences[i].length;
+    }
+
+    *codePoint = -1;
+    return 1;
+}
+
+static size_t reference_utf8_to_utf16(const char* source, size_t sourceLength, CHAR16_T* destination, bool* invalid)
+{
+    const unsigned char* p = (const unsigned char*)source;
+    size_t written = 0;
+
+    *invalid = false;
+    for (size_t i = 0; i < sourceLength;)
+    {
+        int32_t codePoint;
+        i += reference_decode_utf8(p + i, sourceLength - i, &codePoint);
+        if (codePoint < 0)
+        {
+            *invalid = true;
+            codePoint = REPLACEMENT_CHAR;
+        }
+
+        if (codePoint >= 0x10000)
+        {
+            destination[written++] = (CHAR16_T)(0xD800 + ((codePoint - 0x10000) >> 10));
+            destination[written++] = (CHAR16_T)(0xDC00 + (codePoint & 0x3FF));
+        }
+        else
+        {
+            destination[written++] = (CHAR16_T)codePoint;
+        }
+    }
+
+    return written;
+}
+
+// A lone surrogate converts to the replacement character
+static size_t reference_utf16_to_utf8(const CHAR16_T* source, size_t sourceLength, char* destination)
+{
+    unsigned char* p = (unsigned char*)destination;
+    size_t written = 0;
+
+    for (size_t i = 0; i < sourceLength; i++)
+    {
+        uint32_t codePoint = source[i];
+        if (is_high_surrogate(codePoint) && i + 1 < sourceLength && is_low_surrogate(source[i + 1]))
+        {
+            codePoint = 0x10000 + ((codePoint - 0xD800) << 10) + (source[i + 1] - 0xDC00u);
+            i++;
+        }
+        else if (is_high_surrogate(codePoint) || is_low_surrogate(codePoint))
+        {
+            codePoint = REPLACEMENT_CHAR;
+        }
+
+        written += reference_encode_utf8(codePoint, p + written);
+    }
+
+    return written;
+}
+
+// Checks the size query, an exactly sized destination, destinations that are too small, MINIPAL_MB_NO_REPLACE_INVALID_CHARS
+// and MINIPAL_TREAT_AS_LITTLE_ENDIAN for one input. invalid tells whether the input has ill-formed sequences. The buffers
+// have room for capacity code units, more than expectedLength.
+static RESULT check_utf8_to_utf16_in(const char* name, size_t index, size_t variant,
+    const char* source, size_t sourceLength, const CHAR16_T* expected, size_t expectedLength, bool invalid,
+    CHAR16_T* native, CHAR16_T* little, size_t capacity)
+{
+    size_t count;
+    int error;
+
+    errno = ERRNO_SENTINEL;
+    count = minipal_get_length_utf8_to_utf16(source, sourceLength, 0);
+    error = errno;
+    if (count != expectedLength || error != 0)
+    {
+        return FAILED("%s %zu.%zu: minipal_get_length_utf8_to_utf16 returned %zu with errno %d, expected %zu",
+            name, index, variant, count, error, expectedLength);
+    }
+
+    // An exactly sized destination gets the whole string and nothing past it
+    fill_utf16(native, capacity);
+    errno = ERRNO_SENTINEL;
+    count = minipal_convert_utf8_to_utf16(source, sourceLength, native, expectedLength, 0);
+    error = errno;
+    if (count != expectedLength || error != 0 || memcmp(native, expected, expectedLength * sizeof(CHAR16_T)) != 0 ||
+        native[expectedLength] != Utf16Canary)
+    {
+        return FAILED("%s %zu.%zu: minipal_convert_utf8_to_utf16 returned %zu with errno %d, expected %zu, or produced an unexpected string",
+            name, index, variant, count, error, expectedLength);
+    }
+
+    // Destinations that are too small fail without writing past their end
+    if (expectedLength != 0)
+    {
+        const size_t sizes[] = { expectedLength - 1, 0 };
+        for (size_t s = 0; s < ARRAY_SIZE(sizes); s++)
+        {
+            fill_utf16(native, capacity);
+            count = minipal_convert_utf8_to_utf16(source, sourceLength, native, sizes[s], 0);
+            error = errno;
+            if (count != 0 || error != MINIPAL_ERROR_INSUFFICIENT_BUFFER || native[sizes[s]] != Utf16Canary)
+            {
+                return FAILED("%s %zu.%zu: minipal_convert_utf8_to_utf16 into %zu elements returned %zu with errno %d, expected 0 with MINIPAL_ERROR_INSUFFICIENT_BUFFER and nothing written past them",
+                    name, index, variant, sizes[s], count, error);
+            }
+        }
+    }
+
+    // MINIPAL_MB_NO_REPLACE_INVALID_CHARS fails on any ill-formed sequence, including one at the end of the input
+    const size_t strictLength = invalid ? 0 : expectedLength;
+    const int strictError = invalid ? (int)MINIPAL_ERROR_NO_UNICODE_TRANSLATION : 0;
+    errno = ERRNO_SENTINEL;
+    count = minipal_get_length_utf8_to_utf16(source, sourceLength, MINIPAL_MB_NO_REPLACE_INVALID_CHARS);
+    error = errno;
+    if (count != strictLength || error != strictError)
+    {
+        return FAILED("%s %zu.%zu: minipal_get_length_utf8_to_utf16 with MINIPAL_MB_NO_REPLACE_INVALID_CHARS returned %zu with errno %d, expected %zu with errno %d",
+            name, index, variant, count, error, strictLength, strictError);
+    }
+
+    fill_utf16(native, capacity);
+    errno = ERRNO_SENTINEL;
+    count = minipal_convert_utf8_to_utf16(source, sourceLength, native, capacity, MINIPAL_MB_NO_REPLACE_INVALID_CHARS);
+    error = errno;
+    if (count != strictLength || error != strictError || memcmp(native, expected, strictLength * sizeof(CHAR16_T)) != 0)
+    {
+        return FAILED("%s %zu.%zu: minipal_convert_utf8_to_utf16 with MINIPAL_MB_NO_REPLACE_INVALID_CHARS returned %zu with errno %d, expected %zu with errno %d",
+            name, index, variant, count, error, strictLength, strictError);
+    }
+
+    // MINIPAL_TREAT_AS_LITTLE_ENDIAN gives the native result with each code unit byte-swapped on big-endian platforms,
+    // and the native result elsewhere, for any destination size
+    const bool bigEndian = is_big_endian();
+    const unsigned int flagSets[] = { 0, MINIPAL_MB_NO_REPLACE_INVALID_CHARS };
+    const size_t sizes[] = { expectedLength, expectedLength != 0 ? expectedLength - 1 : 0, capacity };
+    for (size_t f = 0; f < ARRAY_SIZE(flagSets); f++)
+    {
+        const unsigned int flags = flagSets[f];
+
+        errno = ERRNO_SENTINEL;
+        size_t nativeCount = minipal_get_length_utf8_to_utf16(source, sourceLength, flags);
+        int nativeError = errno;
+        errno = ERRNO_SENTINEL;
+        size_t littleCount = minipal_get_length_utf8_to_utf16(source, sourceLength, flags | MINIPAL_TREAT_AS_LITTLE_ENDIAN);
+        int littleError = errno;
+        if (littleCount != nativeCount || littleError != nativeError)
+        {
+            return FAILED("%s %zu.%zu: minipal_get_length_utf8_to_utf16 with flags 0x%x returned %zu with errno %d for little-endian, %zu with errno %d otherwise",
+                name, index, variant, flags, littleCount, littleError, nativeCount, nativeError);
+        }
+
+        for (size_t s = 0; s < ARRAY_SIZE(sizes); s++)
+        {
+            fill_utf16(native, capacity);
+            fill_utf16(little, capacity);
+            errno = ERRNO_SENTINEL;
+            nativeCount = minipal_convert_utf8_to_utf16(source, sourceLength, native, sizes[s], flags);
+            nativeError = errno;
+            errno = ERRNO_SENTINEL;
+            littleCount = minipal_convert_utf8_to_utf16(source, sourceLength, little, sizes[s], flags | MINIPAL_TREAT_AS_LITTLE_ENDIAN);
+            littleError = errno;
+            if (littleCount != nativeCount || littleError != nativeError)
+            {
+                return FAILED("%s %zu.%zu: minipal_convert_utf8_to_utf16 with flags 0x%x into %zu elements returned %zu with errno %d for little-endian, %zu with errno %d otherwise",
+                    name, index, variant, flags, sizes[s], littleCount, littleError, nativeCount, nativeError);
+            }
+
+            for (size_t i = 0; i < nativeCount; i++)
+            {
+                const CHAR16_T expectedUnit = bigEndian ? swap_bytes(native[i]) : native[i];
+                if (little[i] != expectedUnit)
+                {
+                    return FAILED("%s %zu.%zu: minipal_convert_utf8_to_utf16 with flags 0x%x into %zu elements wrote 0x%04x at %zu for little-endian, expected 0x%04x",
+                        name, index, variant, flags, sizes[s], (unsigned)little[i], i, (unsigned)expectedUnit);
+                }
+            }
+        }
+    }
+
+    return OK;
+}
+
+static RESULT check_utf8_to_utf16(const char* name, size_t index, size_t variant,
+    const char* source, size_t sourceLength, const CHAR16_T* expected, size_t expectedLength, bool invalid)
+{
+    const size_t capacity = expectedLength + 16;
+    CHAR16_T* native = (CHAR16_T*)malloc(capacity * sizeof(CHAR16_T));
+    CHAR16_T* little = (CHAR16_T*)malloc(capacity * sizeof(CHAR16_T));
+    RESULT result = native != NULL && little != NULL
+        ? check_utf8_to_utf16_in(name, index, variant, source, sourceLength, expected, expectedLength, invalid, native, little, capacity)
+        : FAILED("%s %zu.%zu: out of memory", name, index, variant);
+    free(native);
+    free(little);
+    return result;
+}
+
+// Converts a NUL-terminated string without and with its terminator
+static RESULT check_utf8_string(const char* name, size_t index, size_t variant, const char* utf8, const CHAR16_T* utf16)
+{
+    const size_t utf8Length = strlen(utf8);
+    const size_t utf16Length = utf16_length(utf16);
+    const bool invalid = has_replacement_char(utf16, utf16Length);
+
+    CHECK(check_utf8_to_utf16(name, index, variant, utf8, utf8Length, utf16, utf16Length, invalid));
+    return check_utf8_to_utf16(name, index, variant, utf8, utf8Length + 1, utf16, utf16Length + 1, invalid);
+}
+
+// Embeds the string between ASCII runs long enough to take the fast paths, at every offset modulo 8
+static RESULT check_utf8_string_embedded(const char* name, size_t index, const char* utf8, const CHAR16_T* utf16)
+{
+    const size_t suffix = 16;
+    const size_t utf8Length = strlen(utf8);
+    const size_t utf16Length = utf16_length(utf16);
+    char longUtf8[128];
+    CHAR16_T longUtf16[128];
+
+    for (size_t prefix = 14; prefix < 22; prefix++)
+    {
+        for (size_t j = 0; j < prefix; j++)
+        {
+            longUtf8[j] = (char)('a' + j % 26);
+            longUtf16[j] = (CHAR16_T)('a' + j % 26);
+        }
+
+        memcpy(longUtf8 + prefix, utf8, utf8Length);
+        memcpy(longUtf16 + prefix, utf16, utf16Length * sizeof(CHAR16_T));
+
+        for (size_t j = 0; j < suffix; j++)
+        {
+            longUtf8[prefix + utf8Length + j] = (char)('A' + j);
+            longUtf16[prefix + utf16Length + j] = (CHAR16_T)('A' + j);
+        }
+
+        longUtf8[prefix + utf8Length + suffix] = '\0';
+        longUtf16[prefix + utf16Length + suffix] = 0;
+
+        CHECK(check_utf8_string(name, index, prefix, longUtf8, longUtf16));
+    }
+
+    return OK;
+}
+
+// Checks the size query, an exactly sized destination, destinations that are too small, MINIPAL_MB_NO_REPLACE_INVALID_CHARS
+// and MINIPAL_TREAT_AS_LITTLE_ENDIAN for one input. The buffers have room for capacity bytes, more than expectedLength,
+// and swapped for sourceLength code units.
+static RESULT check_utf16_to_utf8_in(const char* name, size_t index, size_t variant,
+    const CHAR16_T* source, size_t sourceLength, const char* expected, size_t expectedLength,
+    char* native, char* little, CHAR16_T* swapped, size_t capacity)
+{
+    size_t count;
+    int error;
+
+    errno = ERRNO_SENTINEL;
+    count = minipal_get_length_utf16_to_utf8(source, sourceLength, 0);
+    error = errno;
+    if (count != expectedLength || error != 0)
+    {
+        return FAILED("%s %zu.%zu: minipal_get_length_utf16_to_utf8 returned %zu with errno %d, expected %zu",
+            name, index, variant, count, error, expectedLength);
+    }
+
+    // An exactly sized destination gets the whole string and nothing past it
+    memset(native, Utf8Canary, capacity);
+    errno = ERRNO_SENTINEL;
+    count = minipal_convert_utf16_to_utf8(source, sourceLength, native, expectedLength, 0);
+    error = errno;
+    if (count != expectedLength || error != 0 || memcmp(native, expected, expectedLength) != 0 || native[expectedLength] != Utf8Canary)
+    {
+        return FAILED("%s %zu.%zu: minipal_convert_utf16_to_utf8 returned %zu with errno %d, expected %zu, or produced an unexpected string",
+            name, index, variant, count, error, expectedLength);
+    }
+
+    // Destinations that are too small fail without writing past their end
+    if (expectedLength != 0)
+    {
+        const size_t sizes[] = { expectedLength - 1, 0 };
+        for (size_t s = 0; s < ARRAY_SIZE(sizes); s++)
+        {
+            memset(native, Utf8Canary, capacity);
+            count = minipal_convert_utf16_to_utf8(source, sourceLength, native, sizes[s], 0);
+            error = errno;
+            if (count != 0 || error != MINIPAL_ERROR_INSUFFICIENT_BUFFER || native[sizes[s]] != Utf8Canary)
+            {
+                return FAILED("%s %zu.%zu: minipal_convert_utf16_to_utf8 into %zu bytes returned %zu with errno %d, expected 0 with MINIPAL_ERROR_INSUFFICIENT_BUFFER and nothing written past them",
+                    name, index, variant, sizes[s], count, error);
+            }
+        }
+    }
+
+    // MINIPAL_MB_NO_REPLACE_INVALID_CHARS only applies to UTF-8 input, lone surrogates are always replaced
+    errno = ERRNO_SENTINEL;
+    count = minipal_get_length_utf16_to_utf8(source, sourceLength, MINIPAL_MB_NO_REPLACE_INVALID_CHARS);
+    error = errno;
+    if (count != expectedLength || error != 0)
+    {
+        return FAILED("%s %zu.%zu: minipal_get_length_utf16_to_utf8 with MINIPAL_MB_NO_REPLACE_INVALID_CHARS returned %zu with errno %d, expected %zu",
+            name, index, variant, count, error, expectedLength);
+    }
+
+    memset(native, Utf8Canary, capacity);
+    errno = ERRNO_SENTINEL;
+    count = minipal_convert_utf16_to_utf8(source, sourceLength, native, capacity, MINIPAL_MB_NO_REPLACE_INVALID_CHARS);
+    error = errno;
+    if (count != expectedLength || error != 0 || memcmp(native, expected, expectedLength) != 0)
+    {
+        return FAILED("%s %zu.%zu: minipal_convert_utf16_to_utf8 with MINIPAL_MB_NO_REPLACE_INVALID_CHARS returned %zu with errno %d, expected %zu",
+            name, index, variant, count, error, expectedLength);
+    }
+
+    // With MINIPAL_TREAT_AS_LITTLE_ENDIAN, the input with each code unit byte-swapped on big-endian platforms converts
+    // like the native input, and the flag changes nothing elsewhere, for any destination size
+    const bool bigEndian = is_big_endian();
+    for (size_t i = 0; i < sourceLength; i++)
+        swapped[i] = bigEndian ? swap_bytes(source[i]) : source[i];
+
+    const unsigned int flagSets[] = { 0, MINIPAL_MB_NO_REPLACE_INVALID_CHARS };
+    const size_t sizes[] = { expectedLength, expectedLength != 0 ? expectedLength - 1 : 0, capacity };
+    for (size_t f = 0; f < ARRAY_SIZE(flagSets); f++)
+    {
+        const unsigned int flags = flagSets[f];
+
+        errno = ERRNO_SENTINEL;
+        size_t nativeCount = minipal_get_length_utf16_to_utf8(source, sourceLength, flags);
+        int nativeError = errno;
+        errno = ERRNO_SENTINEL;
+        size_t littleCount = minipal_get_length_utf16_to_utf8(swapped, sourceLength, flags | MINIPAL_TREAT_AS_LITTLE_ENDIAN);
+        int littleError = errno;
+        if (littleCount != nativeCount || littleError != nativeError)
+        {
+            return FAILED("%s %zu.%zu: minipal_get_length_utf16_to_utf8 with flags 0x%x returned %zu with errno %d for little-endian, %zu with errno %d otherwise",
+                name, index, variant, flags, littleCount, littleError, nativeCount, nativeError);
+        }
+
+        for (size_t s = 0; s < ARRAY_SIZE(sizes); s++)
+        {
+            memset(native, Utf8Canary, capacity);
+            memset(little, Utf8Canary, capacity);
+            errno = ERRNO_SENTINEL;
+            nativeCount = minipal_convert_utf16_to_utf8(source, sourceLength, native, sizes[s], flags);
+            nativeError = errno;
+            errno = ERRNO_SENTINEL;
+            littleCount = minipal_convert_utf16_to_utf8(swapped, sourceLength, little, sizes[s], flags | MINIPAL_TREAT_AS_LITTLE_ENDIAN);
+            littleError = errno;
+            if (littleCount != nativeCount || littleError != nativeError || memcmp(little, native, nativeCount) != 0)
+            {
+                return FAILED("%s %zu.%zu: minipal_convert_utf16_to_utf8 with flags 0x%x into %zu bytes returned %zu with errno %d for little-endian, %zu with errno %d otherwise, or different bytes",
+                    name, index, variant, flags, sizes[s], littleCount, littleError, nativeCount, nativeError);
+            }
+        }
+    }
+
+    return OK;
+}
+
+static RESULT check_utf16_to_utf8(const char* name, size_t index, size_t variant,
+    const CHAR16_T* source, size_t sourceLength, const char* expected, size_t expectedLength)
+{
+    const size_t capacity = expectedLength + 16;
+    char* native = (char*)malloc(capacity);
+    char* little = (char*)malloc(capacity);
+    CHAR16_T* swapped = (CHAR16_T*)malloc((sourceLength + 1) * sizeof(CHAR16_T));
+    RESULT result = native != NULL && little != NULL && swapped != NULL
+        ? check_utf16_to_utf8_in(name, index, variant, source, sourceLength, expected, expectedLength, native, little, swapped, capacity)
+        : FAILED("%s %zu.%zu: out of memory", name, index, variant);
+    free(native);
+    free(little);
+    free(swapped);
+    return result;
+}
+
+// Converts a NUL-terminated string without and with its terminator
+static RESULT check_utf16_string(const char* name, size_t index, size_t variant, const CHAR16_T* utf16, const char* utf8)
+{
+    const size_t utf16Length = utf16_length(utf16);
+    const size_t utf8Length = strlen(utf8);
+
+    CHECK(check_utf16_to_utf8(name, index, variant, utf16, utf16Length, utf8, utf8Length));
+    return check_utf16_to_utf8(name, index, variant, utf16, utf16Length + 1, utf8, utf8Length + 1);
+}
+
+// Embeds the string between ASCII runs long enough to take the fast paths, at every offset modulo 8
+static RESULT check_utf16_string_embedded(const char* name, size_t index, const CHAR16_T* utf16, const char* utf8)
+{
+    const size_t suffix = 16;
+    const size_t utf16Length = utf16_length(utf16);
+    const size_t utf8Length = strlen(utf8);
+    CHAR16_T longUtf16[128];
+    char longUtf8[128];
+
+    for (size_t prefix = 14; prefix < 22; prefix++)
+    {
+        for (size_t j = 0; j < prefix; j++)
+        {
+            longUtf16[j] = (CHAR16_T)('a' + j % 26);
+            longUtf8[j] = (char)('a' + j % 26);
+        }
+
+        memcpy(longUtf16 + prefix, utf16, utf16Length * sizeof(CHAR16_T));
+        memcpy(longUtf8 + prefix, utf8, utf8Length);
+
+        for (size_t j = 0; j < suffix; j++)
+        {
+            longUtf16[prefix + utf16Length + j] = (CHAR16_T)('A' + j);
+            longUtf8[prefix + utf8Length + j] = (char)('A' + j);
+        }
+
+        longUtf16[prefix + utf16Length + suffix] = 0;
+        longUtf8[prefix + utf8Length + suffix] = '\0';
+
+        CHECK(check_utf16_string(name, index, prefix, longUtf16, longUtf8));
+    }
+
+    return OK;
+}
+
+static uint32_t next_random(uint32_t* state)
+{
+    uint32_t x = *state;
+    x ^= x << 13;
+    x ^= x >> 17;
+    x ^= x << 5;
+    return *state = x;
+}
+
+static uint32_t random_code_point(uint32_t* state, uint32_t kind)
+{
+    uint32_t r = next_random(state);
+    switch (kind % 4)
+    {
+        case 0:
+            return r % 0x80;
+        case 1:
+            return 0x80 + r % (0x800 - 0x80);
+        case 2:
+        {
+            uint32_t codePoint = 0x800 + r % (0x10000 - 0x800 - 0x800);
+            return codePoint >= 0xD800 ? codePoint + 0x800 : codePoint;
+        }
+        default:
+            return 0x10000 + r % 0x100000;
+    }
+}
+
+#define RANDOM_PIECES 24
+#define RANDOM_RUN 24
+#define RANDOM_UTF8_CAPACITY (RANDOM_PIECES * RANDOM_RUN * 4)
+
+// Runs of characters of one length, which the fast paths stay in, mixed with the kinds of ill-formed sequences that
+// make them stop
+static size_t random_utf8(uint32_t* state, char* buffer)
+{
+    static const unsigned char invalidLeads[] = { 0xC0, 0xC1, 0xE0, 0xED, 0xF0, 0xF4, 0xF5, 0xF8, 0xFE, 0xFF };
+    unsigned char* p = (unsigned char*)buffer;
+    size_t length = 0;
+    size_t pieces = 1 + next_random(state) % RANDOM_PIECES;
+
+    for (size_t piece = 0; piece < pieces; piece++)
+    {
+        uint32_t r = next_random(state);
+        size_t run = 1 + (r >> 8) % RANDOM_RUN;
+        switch (r % 8)
+        {
+            case 0:
+            case 1:
+            case 2:
+            case 3:
+                // a run of 1, 2, 3 or 4 byte encoded characters
+                for (size_t i = 0; i < run; i++)
+                    length += reference_encode_utf8(random_code_point(state, r), p + length);
+                break;
+            case 4:
+                // characters of any length
+                for (size_t i = 0; i < run; i++)
+                    length += reference_encode_utf8(random_code_point(state, next_random(state)), p + length);
+                break;
+            case 5:
+                // a byte that isn't ASCII
+                p[length++] = (unsigned char)(0x80 | next_random(state));
+                break;
+            case 6:
+            {
+                // an incomplete 2, 3 or 4 byte encoded character
+                unsigned char sequence[4];
+                size_t sequenceLength = reference_encode_utf8(random_code_point(state, 1 + next_random(state) % 3), sequence);
+                size_t keep = 1 + next_random(state) % (sequenceLength - 1);
+                memcpy(p + length, sequence, keep);
+                length += keep;
+                break;
+            }
+            default:
+                // a lead byte that is invalid or can start ill-formed sequences, followed by continuation bytes
+                p[length++] = invalidLeads[next_random(state) % ARRAY_SIZE(invalidLeads)];
+                for (size_t i = 0; i < 3; i++)
+                    p[length++] = (unsigned char)(0x80 | (next_random(state) % 0x40));
+                break;
+        }
+    }
+
+    return length;
+}
+
+#define RANDOM_UTF16_CAPACITY (RANDOM_PIECES * RANDOM_RUN * 2)
+
+// Runs of characters of one UTF-8 length, which the fast paths stay in, mixed with lone surrogates
+static size_t random_utf16(uint32_t* state, CHAR16_T* buffer)
+{
+    size_t length = 0;
+    size_t pieces = 1 + next_random(state) % RANDOM_PIECES;
+
+    for (size_t piece = 0; piece < pieces; piece++)
+    {
+        uint32_t r = next_random(state);
+        size_t run = 1 + (r >> 8) % RANDOM_RUN;
+        switch (r % 8)
+        {
+            case 0:
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                // a run of characters of one UTF-8 length, or of any length
+                for (size_t i = 0; i < run; i++)
+                {
+                    uint32_t codePoint = random_code_point(state, r % 8 == 4 ? next_random(state) : r);
+                    if (codePoint >= 0x10000)
+                    {
+                        buffer[length++] = (CHAR16_T)(0xD800 + ((codePoint - 0x10000) >> 10));
+                        buffer[length++] = (CHAR16_T)(0xDC00 + (codePoint & 0x3FF));
+                    }
+                    else
+                    {
+                        buffer[length++] = (CHAR16_T)codePoint;
+                    }
+                }
+                break;
+            case 5:
+                // a lone high surrogate
+                buffer[length++] = (CHAR16_T)(0xD800 + next_random(state) % 0x400);
+                break;
+            case 6:
+                // a lone low surrogate
+                buffer[length++] = (CHAR16_T)(0xDC00 + next_random(state) % 0x400);
+                break;
+            default:
+                // a run of lone high surrogates
+                for (size_t i = 0; i < run; i++)
+                    buffer[length++] = (CHAR16_T)(0xD800 + next_random(state) % 0x400);
+                break;
+        }
+    }
+
+    return length;
+}
+
+// Long runs of one kind of character, around the lengths where the UTF-16 counting flushes its per-lane counts
+static const size_t long_run_lengths[] = { 4095, 4096, 4097, 16383, 16384, 16385, 32767, 32768, 32769, 32776, 65537 };
+#define LONG_RUN_KINDS 7
+
+static void make_long_run(size_t kind, CHAR16_T* buffer, size_t length)
+{
+    for (size_t i = 0; i < length; i++)
+    {
+        switch (kind)
+        {
+            case 0: buffer[i] = (CHAR16_T)('a' + i % 26); break;
+            case 1: buffer[i] = 0x0080; break;
+            case 2: buffer[i] = (i % 2 == 0) ? (CHAR16_T)'A' : (CHAR16_T)0x07FF; break;
+            case 3: buffer[i] = 0x0800; break;
+            case 4: buffer[i] = (i % 2 == 0) ? (CHAR16_T)0xD83D : (CHAR16_T)0xDE00; break;
+            case 5: buffer[i] = (i % 3 == 0) ? (CHAR16_T)'A' : (i % 3 == 1) ? (CHAR16_T)0x07FF : (CHAR16_T)0xFFFF; break;
+            default: buffer[i] = (CHAR16_T)((i % 1000 == 999) ? 0xD800 : 0x00E9); break;
+        }
+    }
+}
+
+static RESULT test_utf8_to_utf16_valid_strings(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(valid_strings); i++)
+        CHECK(check_utf8_string("valid string", i, 0, valid_strings[i].utf8, valid_strings[i].utf16));
+
+    return OK;
+}
+
+static RESULT test_utf8_to_utf16_invalid_strings(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(invalid_utf8_strings); i++)
+        CHECK(check_utf8_string("invalid string", i, 0, invalid_utf8_strings[i].utf8, invalid_utf8_strings[i].utf16));
+
+    return OK;
+}
+
+static RESULT test_utf8_to_utf16_long_strings(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(valid_strings); i++)
+        CHECK(check_utf8_string_embedded("long valid string", i, valid_strings[i].utf8, valid_strings[i].utf16));
+
+    for (size_t i = 0; i < ARRAY_SIZE(invalid_utf8_strings); i++)
+        CHECK(check_utf8_string_embedded("long invalid string", i, invalid_utf8_strings[i].utf8, invalid_utf8_strings[i].utf16));
+
+    return OK;
+}
+
+static RESULT test_utf8_to_utf16_embedded_nuls(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(utf8_strings_with_nuls); i++)
+    {
+        const CountedStringPair* pair = &utf8_strings_with_nuls[i];
+        CHECK(check_utf8_to_utf16("string with NULs", i, 0, pair->utf8, pair->utf8Length, pair->utf16, pair->utf16Length,
+            has_replacement_char(pair->utf16, pair->utf16Length)));
+    }
+
+    return OK;
+}
+
+static RESULT test_utf8_to_utf16_long_runs(void)
+{
+    const size_t maxLength = long_run_lengths[ARRAY_SIZE(long_run_lengths) - 1];
+    CHAR16_T* utf16 = (CHAR16_T*)malloc(maxLength * sizeof(CHAR16_T));
+    CHAR16_T* expected = (CHAR16_T*)malloc(maxLength * sizeof(CHAR16_T));
+    char* utf8 = (char*)malloc(maxLength * 3);
+    RESULT result = utf16 != NULL && expected != NULL && utf8 != NULL ? OK : FAILED("out of memory");
+
+    for (size_t kind = 0; kind < LONG_RUN_KINDS && result == OK; kind++)
+    {
+        for (size_t i = 0; i < ARRAY_SIZE(long_run_lengths) && result == OK; i++)
+        {
+            bool invalid;
+            make_long_run(kind, utf16, long_run_lengths[i]);
+            size_t utf8Length = reference_utf16_to_utf8(utf16, long_run_lengths[i], utf8);
+            size_t expectedLength = reference_utf8_to_utf16(utf8, utf8Length, expected, &invalid);
+            result = check_utf8_to_utf16("long run", kind, long_run_lengths[i], utf8, utf8Length, expected, expectedLength, invalid);
+        }
+    }
+
+    free(utf16);
+    free(expected);
+    free(utf8);
+    return result;
+}
+
+// Random input checked against the reference model
+static RESULT test_utf8_to_utf16_random(void)
+{
+    uint32_t state = 0x2545F491;
+    char* source = (char*)malloc(RANDOM_UTF8_CAPACITY);
+    CHAR16_T* expected = (CHAR16_T*)malloc(RANDOM_UTF8_CAPACITY * sizeof(CHAR16_T));
+    RESULT result = source != NULL && expected != NULL ? OK : FAILED("out of memory");
+
+    for (size_t i = 0; i < 2000 && result == OK; i++)
+    {
+        bool invalid;
+        size_t sourceLength = random_utf8(&state, source);
+        size_t expectedLength = reference_utf8_to_utf16(source, sourceLength, expected, &invalid);
+        result = check_utf8_to_utf16("random string", i, 0, source, sourceLength, expected, expectedLength, invalid);
+    }
+
+    free(source);
+    free(expected);
+    return result;
+}
+
+static RESULT test_utf16_to_utf8_valid_strings(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(valid_strings); i++)
+        CHECK(check_utf16_string("valid string", i, 0, valid_strings[i].utf16, valid_strings[i].utf8));
+
+    return OK;
+}
+
+static RESULT test_utf16_to_utf8_invalid_strings(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(invalid_utf16_strings); i++)
+        CHECK(check_utf16_string("invalid string", i, 0, invalid_utf16_strings[i].utf16, invalid_utf16_strings[i].utf8));
+
+    return OK;
+}
+
+static RESULT test_utf16_to_utf8_long_strings(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(valid_strings); i++)
+        CHECK(check_utf16_string_embedded("long valid string", i, valid_strings[i].utf16, valid_strings[i].utf8));
+
+    for (size_t i = 0; i < ARRAY_SIZE(invalid_utf16_strings); i++)
+        CHECK(check_utf16_string_embedded("long invalid string", i, invalid_utf16_strings[i].utf16, invalid_utf16_strings[i].utf8));
+
+    return OK;
+}
+
+static RESULT test_utf16_to_utf8_embedded_nuls(void)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(utf16_strings_with_nuls); i++)
+    {
+        const CountedStringPair* pair = &utf16_strings_with_nuls[i];
+        CHECK(check_utf16_to_utf8("string with NULs", i, 0, pair->utf16, pair->utf16Length, pair->utf8, pair->utf8Length));
+    }
+
+    return OK;
+}
+
+static RESULT test_utf16_to_utf8_long_runs(void)
+{
+    const size_t maxLength = long_run_lengths[ARRAY_SIZE(long_run_lengths) - 1];
+    CHAR16_T* utf16 = (CHAR16_T*)malloc(maxLength * sizeof(CHAR16_T));
+    char* expected = (char*)malloc(maxLength * 3);
+    RESULT result = utf16 != NULL && expected != NULL ? OK : FAILED("out of memory");
+
+    for (size_t kind = 0; kind < LONG_RUN_KINDS && result == OK; kind++)
+    {
+        for (size_t i = 0; i < ARRAY_SIZE(long_run_lengths) && result == OK; i++)
+        {
+            make_long_run(kind, utf16, long_run_lengths[i]);
+            size_t expectedLength = reference_utf16_to_utf8(utf16, long_run_lengths[i], expected);
+            result = check_utf16_to_utf8("long run", kind, long_run_lengths[i], utf16, long_run_lengths[i], expected, expectedLength);
+        }
+    }
+
+    free(utf16);
+    free(expected);
+    return result;
+}
+
+// Random input checked against the reference model
+static RESULT test_utf16_to_utf8_random(void)
+{
+    uint32_t state = 0x9E3779B9;
+    CHAR16_T* source = (CHAR16_T*)malloc(RANDOM_UTF16_CAPACITY * sizeof(CHAR16_T));
+    char* expected = (char*)malloc(RANDOM_UTF16_CAPACITY * 3);
+    RESULT result = source != NULL && expected != NULL ? OK : FAILED("out of memory");
+
+    for (size_t i = 0; i < 2000 && result == OK; i++)
+    {
+        size_t sourceLength = random_utf16(&state, source);
+        size_t expectedLength = reference_utf16_to_utf8(source, sourceLength, expected);
+        result = check_utf16_to_utf8("random string", i, 0, source, sourceLength, expected, expectedLength);
+    }
+
+    free(source);
+    free(expected);
+    return result;
+}
+
+static Test minipal_utf8_tests[] =
+{
+    {"test_utf8_to_utf16_valid_strings", test_utf8_to_utf16_valid_strings},
+    {"test_utf8_to_utf16_invalid_strings", test_utf8_to_utf16_invalid_strings},
+    {"test_utf8_to_utf16_long_strings", test_utf8_to_utf16_long_strings},
+    {"test_utf8_to_utf16_embedded_nuls", test_utf8_to_utf16_embedded_nuls},
+    {"test_utf8_to_utf16_long_runs", test_utf8_to_utf16_long_runs},
+    {"test_utf8_to_utf16_random", test_utf8_to_utf16_random},
+    {"test_utf16_to_utf8_valid_strings", test_utf16_to_utf8_valid_strings},
+    {"test_utf16_to_utf8_invalid_strings", test_utf16_to_utf8_invalid_strings},
+    {"test_utf16_to_utf8_long_strings", test_utf16_to_utf8_long_strings},
+    {"test_utf16_to_utf8_embedded_nuls", test_utf16_to_utf8_embedded_nuls},
+    {"test_utf16_to_utf8_long_runs", test_utf16_to_utf8_long_runs},
+    {"test_utf16_to_utf8_random", test_utf16_to_utf8_random},
+    {NULL, NULL}
+};
+
+DEFINE_TEST_GROUP_INIT(minipal_utf8_tests_init, minipal_utf8_tests)