tinyramfs/generate
2020-02-19 09:47:48 +03:00

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#!/bin/sh
#
# tiny initramfs generation tool
# print message
msg() {
case "$1" in
info)
printf "info >> %s\n" "$2" >&2
;;
warn)
printf "warning >> %s\n" "$2" >&2
printf "do you want to continue? press enter or ctrl+c to exit\n"
read -r _
;;
panic)
printf "panic >> %s\n" "$2" >&2
exit 1
;;
esac
}
create_wrkdir() {
msg info "creating working directory"
if [ "$XDG_CACHE_HOME" ]; then
wrkdir="${XDG_CACHE_HOME}/initramfs.$$"
elif [ "$TMPDIR" ]; then
wrkdir="${TMPDIR}/initramfs.$$"
else
wrkdir="/tmp/initramfs.$$"
fi
mkdir "$wrkdir" || msg panic "failed to create working directory"
}
remove_wrkdir() {
msg info "removing working directory"
rm -rf "$wrkdir"
}
# change current directory to script directory if user haven't do it
check_currentdir() {
scriptdir=$(readlink -f $(dirname "$0"))
[ "$PWD" = "$scriptdir" ] || {
msg info "changing current directory to script directory"
cd "$scriptdir" || msg panic "failed to change directory"
}
}
install_requirements() {
msg info "installing requirements"
# install user specified binaries
[ "$binaries" ] && install_binary "$binaries"
# install util-linux binaries
[ "$util_linux" = 1 ] && install_binary mount blkid
# install mandatory binaries
install_binary busybox modprobe
}
create_structure() {
msg info "creating directory structure"
for dir in dev tmp var run etc usr/lib usr/bin mnt/root proc root sys; do
mkdir -p "${wrkdir}/${dir}"
done
}
# some dynamically linked libraries and binaries compiled with hardcoded
# dependencies path. to make it worked we need create symlinks for them.
# also POSIX ln doesn't have --relative flag like in GNU ln. as workaround
# we change directory to wrkdir and make needed symlinks.
create_symlinks() {
msg info "creating symlinks"
( cd "$wrkdir" && {
ln -s usr/lib lib
ln -s usr/lib lib64
ln -s usr/bin bin
ln -s usr/bin sbin
ln -s ../run var/run
cd "${wrkdir}/usr"
ln -s bin sbin
ln -s lib lib64
} )
}
#parse_fstab() {
# TODO parse fstab
#while [ "$fstab" -eq 1 ] && read fs dir type opts; do thing; done < /etc/fstab
#}
#parse_crypttab() {
# TODO parse crypttab
#}
install_mdev() {
msg info "installing mdev"
install -m644 mdev.conf -t "${wrkdir}/etc"
install -Dm755 storage-device -t "${wrkdir}/lib/mdev"
}
install_mdevd() {
msg info "installing mdevd"
install_binary mdevd mdevd-coldplug
install -m644 mdev.conf -t "${wrkdir}/etc"
install -Dm755 storage-device -t "${wrkdir}/lib/mdev"
}
install_udev() {
msg info "installing udev"
install_binary udevd udevadm dmsetup
# FIXME rewrite this piece of crap
find /usr/lib/udev -type f | grep -v "rc_keymaps\|hwdb.d" | cpio -pd "$wrkdir" > /dev/null 2>&1
}
install_lvm() {
msg info "installing LVM"
install_binary lvm
lvm_drivers="dm-thin-pool dm-multipath dm-snapshot dm-cache dm-log dm-mirror"
[ "$hostonly" = 1 ] && install_driver "$lvm_drivers"
# install lvm config
if [ "$lvm_conf" = 1 ]; then
install -Dm644 /etc/lvm/*.conf -t "${wrkdir}/etc/lvm" || msg panic "failed to install LVM config"
else
mkdir "${wrkdir}/etc/lvm"
cat << EOF > "${wrkdir}/etc/lvm/lvm.conf"
devices {
# block discard support
issue_discards = ${lvm_discard:-0}
}
global {
# disable lvmetad
use_lvmetad = 0
}
EOF
fi
}
install_luks() {
msg info "installing LUKS"
install_binary cryptsetup
luks_drivers="aes dm-crypt sha256 sha512 wp512 ecb lrw xts twofish serpent"
[ "$hostonly" = 1 ] && install_driver "$luks_drivers"
# avoid "locking directory missing" warning message
mkdir "${wrkdir}/run/cryptsetup"
# TODO get rid of this workaround
# workaround for luks2
install -s -m755 /usr/lib/libgcc_s.so.1 -t "${wrkdir}/usr/lib" || msg panic "failed to install LUKS libraries"
# block discard support
[ "$luks_discard" = 1 ] && luks_args="--allow-discards $luks_args"
# copy luks header
[ -f "$luks_header" ] && {
install -m400 "$luks_header" "${wrkdir}/root/luks_header" || msg panic "failed to copy LUKS header"
luks_args="--header=/root/luks_header $luks_args"
}
# copy luks keyfile
[ -f "$luks_keyfile" ] && {
install -m400 "$luks_keyfile" "${wrkdir}/root/luks_keyfile" || msg panic "failed to copy LUKS keyfile"
luks_args="--key-file=/root/luks_keyfile $luks_args"
}
}
install_driver() {
# check monolithic kernel(builtin drivers)
[ -d "${moddir}/${kernel}" ] || return 0
printf "%s\n" "$@" | while read -r driver; do
# strip path and extension
driver="${driver##*/}"
driver="${driver%%.*}"
# TODO busybox modprobe doesn't support -S option
modprobe -S "$kernel" -D "$driver" 2> /dev/null | grep -v builtin | cut -d " " -f 2 | while read -r driver_dep; do
install -Dm644 "$driver_dep" "${wrkdir}${driver_dep}"
done
done
}
install_hostonly_drivers() {
msg info "installing hostonly drivers"
[ "$root_type" ] || msg panic "hostonly mode required root_type option to be configured"
# perform autodetection of drivers via /sys
install_driver "$(find /sys -name modalias -exec sort -u "{}" "+")"
# TODO autodetect root fs driver
# TODO separate root type option
# install root fs driver
install_driver "$root_type"
# install user specified drivers
[ "$drivers" ] && install_driver "$drivers"
}
install_all_drivers() {
msg info "installing all drivers"
modker="${moddir}/${kernel}/kernel"
install_driver \
"$(find \
"${modker}/arch" \
"${modker}/crypto" \
"${modker}/fs" \
"${modker}/lib" \
"${modker}/drivers/block" \
"${modker}/drivers/ata" \
"${modker}/drivers/md" \
"${modker}/drivers/scsi" \
"${modker}/drivers/usb/storage" \
"${modker}/drivers/usb/host" \
"${modker}/drivers/virtio" \
-type f 2> /dev/null)"
}
generate_depmod() {
msg info "running depmod"
modker="${moddir}/${kernel}"
cp "${modker}/modules.builtin" "${modker}/modules.order" "${wrkdir}/${modker}"
depmod -b "$wrkdir" "$kernel"
}
# TODO make strip optional
install_binary() {
printf "%s\n" "$@" | while read -r binary; do
msg info "installing binary $binary"
# check binary existence
command -v "$binary" > /dev/null 2>&1 || msg panic "$binary doesn't exists"
# install and strip binary
install -s -m755 "$(command -v $binary)" -t "${wrkdir}/usr/bin"
# check statically linking
ldd "$(command -v $binary)" > /dev/null 2>&1 || continue
# install libraries
install_library "$binary"
done
}
# TODO make strip optional
install_library() {
ldd "$(command -v $1)" | sed -nre 's,.* (/.*lib.*/.*.so.*) .*,\1,p' -e 's,.*(/lib.*/ld.*.so.*) .*,\1,p' | while read -r library; do
# check symlink
if [ -h "$library" ]; then
# check lib already existence
if [ ! -e "${wrkdir}/usr/lib/${library##*/}" ] && [ ! -e "${wrkdir}/$(readlink -f $library)" ]; then
# regular
install -s -m755 "$(readlink -f $library)" -t "${wrkdir}/usr/lib"
# FIXME handle all symlinks
# symlink may link to symlink
[ -h "/usr/lib/$(readlink $library)" ] && cp -a "/usr/lib/$(readlink $library)" "${wrkdir}/usr/lib"
# symlink
cp -a "$library" "${wrkdir}/usr/lib"
fi
else
if [ ! -e "${wrkdir}/usr/lib/${library##*/}" ]; then
install -s -m755 "$library" -t "${wrkdir}/usr/lib"
fi
fi
done
}
install_files() {
msg info "installing files"
# FIXME eof broken
# initialize config
cat << EOF > "${wrkdir}/config"
debug="$debug"
root="$root"
root_type="$root_type"
root_args="$root_args"
devmgr="$devmgr"
#drivers="$drivers"
lvm="$lvm"
luks="$luks"
luks_root="$luks_root"
luks_args="$luks_args"
EOF
# needed for devmgr
cat << EOF > "${wrkdir}/etc/group"
root:x:0:
tty:x:5:
dialout:x:11:
uucp:x:14:
kmem:x:3:
input:x:25:
video:x:13:
audio:x:12:
lp:x:10:
disk:x:9:
cdrom:x:16:
tape:x:6:
kvm:x:24:
floppy:x:8:
EOF
# needed for devmgr
cat << EOF > "${wrkdir}/etc/passwd"
root:x:0:0::/root:/bin/sh
nobody:x:99:99::/:/bin/false
EOF
# install init script
install -m755 ./init -t "$wrkdir"
}
# create and compress cpio archive
create_initramfs() {
msg info "creating initramfs image"
{
(
cd "$wrkdir"
find . | cpio -oH newc | ${compress:-gzip -9}
) | tee "${scriptdir}/${initramfs:=initramfs-${kernel}}"
} > /dev/null 2>&1 || msg panic "failed to generate initramfs image"
}
# check root
[ "$(id -u)" = 0 ] || msg panic "must be run as root"
create_wrkdir
# remove wrkdir on exit or unexpected error
trap remove_wrkdir EXIT INT
check_currentdir
. ./config || msg panic "failed to source config"
[ "$debug" = 1 ] && {
# debug shell commands
set -x
# don't remove anything
trap : EXIT INT
}
kernel="${kernel:-$(uname -r)}"
moddir="/lib/modules"
create_structure
create_symlinks
#parse_fstab
#parse_crypttab
install_requirements
if [ "$hostonly" = 1 ]; then
install_hostonly_drivers
else
install_all_drivers
fi
generate_depmod
case "$devmgr" in
mdev) install_mdev ;;
mdevd) install_mdevd ;;
udev) install_udev ;;
*) msg panic "devmgr option broken" ;;
esac
[ "$luks" = 1 ] && install_luks
[ "$lvm" = 1 ] && install_lvm
install_files
create_initramfs
msg info "done! check out $initramfs"