ARC: migrate to the generic rule for built-in DTB

Commit 654102d ("kbuild: add generic support for built-in boot
DTBs") introduced generic support for built-in DTBs.

Select GENERIC_BUILTIN_DTB to use the generic rule.

To keep consistency across architectures, this commit also renames
CONFIG_ARC_BUILTIN_DTB_NAME to CONFIG_BUILTIN_DTB_NAME.

Now, "nsim_700" is the default value for CONFIG_BUILTIN_DTB_NAME, rather
than a fallback in case it is empty.

Acked-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Author: masahir0y

arch/arc/Kconfig

@@ -18,6 +18,7 @@ config ARC
 	select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
 	select ARCH_32BIT_OFF_T
 	select BUILDTIME_TABLE_SORT
+	select GENERIC_BUILTIN_DTB
 	select CLONE_BACKWARDS
 	select COMMON_CLK
 	select DMA_DIRECT_REMAP
@@ -551,11 +552,11 @@ config ARC_DBG_JUMP_LABEL
 	  part of static keys (jump labels) related code.
 endif
 
-config ARC_BUILTIN_DTB_NAME
+config BUILTIN_DTB_NAME
 	string "Built in DTB"
+	default "nsim_700"
 	help
-	  Set the name of the DTB to embed in the vmlinux binary
-	  Leaving it blank selects the "nsim_700" dtb.
+	  Set the name of the DTB to embed in the vmlinux binary.
 
 endmenu	 # "ARC Architecture Configuration"
 

arch/arc/Makefile

@@ -82,9 +82,6 @@ KBUILD_CFLAGS	+= $(cflags-y)
 KBUILD_AFLAGS	+= $(KBUILD_CFLAGS)
 KBUILD_LDFLAGS	+= $(ldflags-y)
 
-# w/o this dtb won't embed into kernel binary
-core-y		+= arch/arc/boot/dts/
-
 core-y				+= arch/arc/plat-sim/
 core-$(CONFIG_ARC_PLAT_TB10X)	+= arch/arc/plat-tb10x/
 core-$(CONFIG_ARC_PLAT_AXS10X)	+= arch/arc/plat-axs10x/

arch/arc/boot/dts/Makefile

@@ -1,13 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
-# Built-in dtb
-builtindtb-y		:= nsim_700
 
-ifneq ($(CONFIG_ARC_BUILTIN_DTB_NAME),)
-	builtindtb-y	:= $(CONFIG_ARC_BUILTIN_DTB_NAME)
-endif
-
-obj-y   += $(builtindtb-y).dtb.o
-dtb-y := $(builtindtb-y).dtb
+dtb-y	:= $(addsuffix .dtb, $(CONFIG_BUILTIN_DTB_NAME))
 
 # for CONFIG_OF_ALL_DTBS test
 dtb-	:= $(patsubst $(src)/%.dts,%.dtb, $(wildcard $(src)/*.dts))

arch/arc/configs/axs101_defconfig

@@ -23,7 +23,7 @@ CONFIG_PARTITION_ADVANCED=y
 CONFIG_ARC_PLAT_AXS10X=y
 CONFIG_AXS101=y
 CONFIG_ARC_CACHE_LINE_SHIFT=5
-CONFIG_ARC_BUILTIN_DTB_NAME="axs101"
+CONFIG_BUILTIN_DTB_NAME="axs101"
 CONFIG_PREEMPT=y
 # CONFIG_COMPACTION is not set
 CONFIG_NET=y

arch/arc/configs/axs103_defconfig

@@ -22,7 +22,7 @@ CONFIG_PARTITION_ADVANCED=y
 CONFIG_ARC_PLAT_AXS10X=y
 CONFIG_AXS103=y
 CONFIG_ISA_ARCV2=y
-CONFIG_ARC_BUILTIN_DTB_NAME="axs103"
+CONFIG_BUILTIN_DTB_NAME="axs103"
 CONFIG_PREEMPT=y
 # CONFIG_COMPACTION is not set
 CONFIG_NET=y

arch/arc/configs/axs103_smp_defconfig

@@ -22,7 +22,7 @@ CONFIG_ARC_PLAT_AXS10X=y
 CONFIG_AXS103=y
 CONFIG_ISA_ARCV2=y
 CONFIG_SMP=y
-CONFIG_ARC_BUILTIN_DTB_NAME="axs103_idu"
+CONFIG_BUILTIN_DTB_NAME="axs103_idu"
 CONFIG_PREEMPT=y
 # CONFIG_COMPACTION is not set
 CONFIG_NET=y

arch/arc/configs/haps_hs_defconfig

@@ -14,7 +14,7 @@ CONFIG_BLK_DEV_INITRD=y
 CONFIG_EXPERT=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_COMPAT_BRK is not set
-CONFIG_ARC_BUILTIN_DTB_NAME="haps_hs"
+CONFIG_BUILTIN_DTB_NAME="haps_hs"
 CONFIG_MODULES=y
 # CONFIG_BLK_DEV_BSG is not set
 # CONFIG_COMPACTION is not set

arch/arc/configs/haps_hs_smp_defconfig

@@ -16,7 +16,7 @@ CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set
 # CONFIG_COMPAT_BRK is not set
 CONFIG_SMP=y
-CONFIG_ARC_BUILTIN_DTB_NAME="haps_hs_idu"
+CONFIG_BUILTIN_DTB_NAME="haps_hs_idu"
 CONFIG_KPROBES=y
 CONFIG_MODULES=y
 # CONFIG_BLK_DEV_BSG is not set

arch/arc/configs/hsdk_defconfig

@@ -20,7 +20,7 @@ CONFIG_ISA_ARCV2=y
 CONFIG_SMP=y
 CONFIG_LINUX_LINK_BASE=0x90000000
 CONFIG_LINUX_RAM_BASE=0x80000000
-CONFIG_ARC_BUILTIN_DTB_NAME="hsdk"
+CONFIG_BUILTIN_DTB_NAME="hsdk"
 CONFIG_PREEMPT=y
 # CONFIG_COMPACTION is not set
 CONFIG_NET=y

arch/arc/configs/nsim_700_defconfig

@@ -17,7 +17,7 @@ CONFIG_PERF_EVENTS=y
 # CONFIG_SLUB_DEBUG is not set
 # CONFIG_COMPAT_BRK is not set
 CONFIG_ISA_ARCOMPACT=y
-CONFIG_ARC_BUILTIN_DTB_NAME="nsim_700"
+CONFIG_BUILTIN_DTB_NAME="nsim_700"
 CONFIG_KPROBES=y
 CONFIG_MODULES=y
 # CONFIG_BLK_DEV_BSG is not set