nullinitrd

An initramfs generator used in NULL GNU/Linux and Redrose GNU/Linux written in C++.

Known issues

• nullinitrd is broken with NVMe drives

Build from source

Clone the repo:

git clone https://github.com/NULL-GNU-Linux/nullinitrd --depth 1
cd nullinitrd

Build:

make defconfig
# make menuconfig
make

Install:

sudo make install

As always, the DESTDIR and PREFIX enviroment variables are supported.

Quick test

We have a script to create a bootable system with nullinitrd.

sh tests/test_system.sh path-to-kernel

Configuration and usage

Rebuild initramfs

Simply run:

nullinitrd

Configuration file

The config.default file has the file written to the configuration file during install.

Option	Default	Description
COMPRESSION	zstd	Compression algorithm to use. Supported: zstd, gzip, xz, lz4, bzip2, lzma, none
ROOTFS_TYPE	ext4	Filesystem type to use when mounting root.
INIT_PATH	/sbin/init	Path to the init binary (NOT the initramfs init.)
AUTODETECT_MODULES	n	Automatically detect and include kernel modules.
MODULES	empty	Additional kernel modules to include (space-separated).
HOOKS	keyboard	Hooks to run during initramfs creation.
FEATURE_LVM	n	Include LVM support.
FEATURE_LUKS	n	Include LUKS support.
FEATURE_MDADM	n	Include MDADM support.
FEATURE_BTRFS	n	Include Btrfs support.
FEATURE_ZFS	n	Include ZFS support.

Kernel Parameters

Parameter	Description
root=	Root device (e.g., /dev/sda1, UUID=..., PARTUUID=..., LABEL=...)
rootfstype=	Root filesystem type
rootflags=	Mount flags for root
rootdelay=	Seconds to wait before mounting root
init=	Path to init on root filesystem
rw	Mount root read-write
ro	Mount root read-only
rd.debug	Enable verbose initramfs output
initrd.debug	Alias for rd.debug
rd.modules=	Additional modules to load (comma-separated)

Build Configuration

Run make menuconfig or edit .config:

Option	Description
CONFIG_STATIC=y	Static linking
CONFIG_DEBUG=y	Debug build
CONFIG_LTO=y	Link-time optimization

Hooks

Custom hooks can be placed in {/etc,/usr/[local]/share}/nullinitrd/hooks/ and enabled via the HOOKS config option.

To create a hook template:

nullinitrd hook-template my-hook

Packaging

.tar.gz

Run:

make tgz-pkg

Creates a tgz with a dir called stage with the files to install and a README.

Car .tar.zst

Run:

make car-pkg

Authors

• neoapps-dev <neo@obsidianos.xyz>
• mostypc123 <mostypc123@redroselinux.org>