make-initrd

make-initrd.sh (1849B)

#!/bin/sh
# Copyright 2017 Haelwenn (lanodan) Monnier <contact+make-initrd@hacktivis.me>
# SPDX-License-Identifier: ISC
elves="busybox blkid lsblk cryptsetup mksh zfs zpool"
WORKDIR="$(pwd)"
die() {
	echo "[Error] die: ${*}"
	exit 1
}
[ -n "$1" ] || die "make-initrd takes kernel version as argument"
kver="$1"
modulesdir="/lib/modules/${kver}"
[ -d "$modulesdir" ] || die "${modulesdir}: Directory not found"
out_base="initramfs-${kver}"
if test -e "$out_base"; then
	rm -fr "$out_base" || die "Failed: rm -fr $out_base"
fi
mkdir -p "$out_base" || die "Failed: mkdir $out_base"
cd "$out_base" || die "Failed: cd $out_base"
mkdir -p bin lib/modules dev proc sys newroot etc || die "Failed creating base directories"
ln -s /proc/mounts etc/mtab || die "Failed symlink for /etc/mtab"
ln -s . usr
ln -s lib lib64
ln -s lib lib32
cp -pr "${modulesdir}" lib/modules/ || die "Failed copying kernel modules"
mknod -m 660 dev/console c 5 1
mknod -m 666 dev/urandom c 1 9
mknod -m 666 dev/random  c 1 8
#mknod -m 640 dev/mem     c 1 1
mknod -m 666 dev/null    c 1 3
mknod -m 666 dev/tty     c 5 0
mknod -m 666 dev/zero    c 1 5
mknod -m 620 dev/tty1    c 4 1
for elf in $elves; do
	origin=$(command -v "$elf")
	cp "$origin" bin/ || die
done
if [ -f /root/initrd-keyfile ]; then
	cp /root/initrd-keyfile ./keyfile || die "copying keyfile"
fi
cp "${WORKDIR}/init" . || die "copying init"
chmod 755 init || die "init chmod"
ln bin/mksh bin/sh || die "default shell link"
for lib in $(find bin -type f -exec lddtree -l {} + | grep -v bin/ | sort | uniq); do
	cp "$lib" lib/ || die
done
if find . -print0 | cpio --null -ov --format=newc | xz -9 --check=crc32 > "../${out_base}.cpio.xz"; then
	test -e "/boot/${out_base}.cpio.xz" && mv "/boot/${out_base}.cpio.xz" "/boot/${out_base}.cpio.xz.old"
	cp "../${out_base}.cpio.xz" /boot
fi
cd "${WORKDIR}"