tinyramfs: code cleanup

This commit is contained in:
illiliti 2021-05-10 14:42:11 +03:00
parent 50d18b28a5
commit bd16dcbd77

120
tinyramfs
View File

@ -1,8 +1,8 @@
#!/bin/sh
#
# tiny initramfs
# Tiny initramfs
#
# false positive
# https://www.shellcheck.net/wiki/SC2154
# shellcheck disable=2154
print()
@ -13,39 +13,27 @@ print()
panic()
{
print "${1:-unexpected error occurred}" \
"\033[1;31m!!\033[m" >&2; exit 1
}
"\033[1;31m!!\033[m"
exit 1
} >&2
usage()
{
cat << EOF
usage: ${0##*/} [option ...]
-o, --output <file> set initramfs output path
default is /boot/initramfs-$(uname -r)
-c, --config <file> set config file path
default is /etc/tinyramfs/config
-m, --modules <dir> set modules directory
default is /lib/modules
-s, --sources <dir> set sources directory
default is /usr/share/tinyramfs
-k, --kernel <ver> set kernel version
default is $(uname -r)
-H, --hooks <dir> set hooks directory
default is /etc/tinyramfs/hooks (user hooks)
and /usr/share/tinyramfs/hooks (system hooks)
-d, --debug enable debug mode
-f, --force overwrite initramfs image
usage: ${0##*/} [option]...
-o, --output <file> set initramfs output path
-c, --config <file> set config file path
-m, --modules <dir> set modules directory
-s, --sources <dir> set sources directory
-k, --kernel <ver> set kernel version
-H, --hooks <dir> set hooks directory
-d, --debug enable debug mode
-f, --force overwrite initramfs image
EOF
}
prepare_environment()
parse_arguments()
{
while [ "$1" ]; do case "$1" in
-o | --output)
@ -76,15 +64,13 @@ prepare_environment()
usage; exit 0
;;
*)
printf "invalid option: %s\n\n" "$1"
printf "invalid option: %s\n" "$1"
usage; exit 1
;;
esac; done
print "preparing environment"
# false positive
# https://www.shellcheck.net/wiki/SC1090
# shellcheck disable=1090
. "${config:=/etc/tinyramfs/config}"
@ -95,7 +81,7 @@ prepare_environment()
mkdir -p "${tmpdir:=${TMPDIR:-/tmp}/tinyramfs.$$}"
# false positive
# https://www.shellcheck.net/wiki/SC2015
# shellcheck disable=2015
[ "$debug" = 1 ] && set -x || trap 'rm -rf $tmpdir' EXIT INT
}
@ -104,7 +90,7 @@ prepare_initramfs()
{
print "preparing initramfs"
# make directories
# https://wikipedia.org/wiki/Filesystem_Hierarchy_Standard
mkdir -p \
"${tmpdir}/dev" \
"${tmpdir}/sys" \
@ -118,7 +104,6 @@ prepare_initramfs()
"${tmpdir}/mnt/root" \
"${tmpdir}/etc/tinyramfs"
# make symlinks
ln -s usr/lib "${tmpdir}/lib"
ln -s usr/bin "${tmpdir}/bin"
ln -s usr/bin "${tmpdir}/sbin"
@ -126,7 +111,6 @@ prepare_initramfs()
ln -s ../run/lock "${tmpdir}/var/lock"
ln -s bin "${tmpdir}/usr/sbin"
# copy required binaries
for _binary in \
\[ sh ln env kill mkdir sleep mount \
printf switch_root "${srcdir}/device-helper"
@ -144,12 +128,11 @@ copy_file()
(
file="$1"; dest="$2"; mode="$3"; strip="$4"
# check if file already exist
[ -e "${tmpdir}${dest}" ] && return 0
mkdir -p "${tmpdir}${dest%/*}" || panic
# iterate throught symlinks and copy them
# Iterate throught symlinks and copy them
while [ -h "$file" ]; do
cp -P "$file" "${tmpdir}${dest%/*}/${file##*/}"
cd -P "${file%/*}"
@ -159,7 +142,7 @@ copy_file()
file="${PWD}/${symlink##*/}"
done
# handle case when file and dest have same basenames
# Handle case when file and dest have same basenames
[ -h "${tmpdir}${dest}" ] && dest="${dest%/*}/${file##*/}"
{
@ -167,7 +150,7 @@ copy_file()
chmod "$mode" "${tmpdir}${dest}"
} || panic
# false positive
# https://www.shellcheck.net/wiki/SC2015
# shellcheck disable=2015
[ "$strip" = 1 ] && strip "${tmpdir}${dest}" > /dev/null 2>&1 || :
)
@ -176,8 +159,13 @@ copy_binary()
{
binary=$(command -v "$1")
# check if binary exist and builtin
# false positive
# If output is
#
# empty, do panic
# external command, do nothing
# builtin command, try to find external alternative.
#
# https://www.shellcheck.net/wiki/SC2086
# shellcheck disable=2086
case "$binary" in */*) ;;
"")
@ -186,21 +174,17 @@ copy_binary()
*)
IFS=:; set -- $PATH; unset IFS
# assume that `command -v` returned builtin command.
# this behavior depends on shell implementation.
# to be independent we simply iterating over PATH
# to find external alternative ( e.g kill => /bin/kill )
for _dir; do
[ -x "${_dir}/${binary}" ] || ! continue
binary="${_dir}/${binary}"
binary="${_dir}/${binary}"; break
[ -x "$binary" ] && break
done || panic "$1 does not exist"
;;
esac
copy_file "$binary" "/bin/${binary##*/}" 755 1
# copy binary dependencies if any
# Copy binary dependencies if any exist.
ldd "$binary" 2> /dev/null |
while read -r _library || [ "$_library" ]; do
@ -222,8 +206,8 @@ copy_module()
while read -r _ module || [ "$module" ]; do
# check if module contains full path(not builtin)
[ "${module##*/*}" ] && continue
# Skip builtin modules.
case "$module" in */*) ;; *) continue; esac
copy_file "$module" "$module" 644 0
done
@ -234,12 +218,12 @@ copy_hook()
hook="$1"
for _dir in "$hksdir" /etc/tinyramfs/hooks /usr/share/tinyramfs/hooks; do
[ -f "${_dir}/${hook}/${hook}" ] || ! continue
[ -f "${_dir}/${hook}/${hook}" ] && break
done || panic "could not find $hook hook"
print "running $hook hook"
# false positive
# https://www.shellcheck.net/wiki/SC1090
# shellcheck disable=1090
. "${_dir}/${hook}/${hook}"
@ -255,22 +239,22 @@ copy_hook()
copy_modules()
{
# skip this function if kernel
# compiled with builtin modules
# Skip this function if kernel
# compiled with builtin modules.
if [ "$monolith" = 1 ]; then
return 0
elif [ "$hostonly" = 1 ]; then
print "copying hostonly modules"
# perform autodetection of modules via /sys
# see https://wiki.archlinux.org/index.php/Modalias
# Perform autodetection of modules via /sys
# https://wiki.archlinux.org/index.php/Modalias
find /sys/devices -name modalias -exec sort -u {} + |
while read -r _module || [ "$_module" ]; do
# skip unneeded modules and skip modules which
# depends on them as well
# Skip unneeded modules and skip modules which
# depends on them as well.
case $(modprobe -S "$kernel" -D "$_module") in
*wmi* | *gpu* | *net*) continue ;;
esac 2> /dev/null
@ -278,16 +262,14 @@ copy_modules()
copy_module "$_module"
done
# copy root filesystem module
if [ "$root_type" ]; then
copy_module "$root_type"
else
while read -r _ _dir _type _; do
[ "$_dir" = / ] || ! continue
[ "$_dir" = / ] && break
done < /proc/mounts || panic "failed to autodetect root fs module"
copy_module "$_type"; break
done < /proc/mounts ||
panic "could not copy root fs module"
copy_module "$_type"
fi
else
print "copying all modules"
@ -308,11 +290,11 @@ copy_modules()
while read -r _module || [ "$_module" ]; do
# strip path and extension
# Strip path and extension
_module="${_module##*/}"
_module="${_module%%.*}"
# skip unneeded modules and skip modules which
# Skip unneeded modules and skip modules which
# depends on them as well
case $(modprobe -S "$kernel" -D "$_module") in
*wmi* | *gpu* | *net*) continue ;;
@ -334,7 +316,6 @@ make_initramfs()
(
print "generating initramfs image"
# check if image already exist
[ "$force" != 1 ] && [ -e "$output" ] &&
panic "initramfs image already exist"
@ -348,13 +329,12 @@ make_initramfs()
[ "$(id -u)" = 0 ] || panic "must be run as root"
# enable exit on error and disable globbing
# Exit if command fails and disable globbing.
set -ef
prepare_environment "$@"
parse_arguments "$@"
prepare_initramfs
# copy and run hooks if any
for _hook in $hooks; do
copy_hook "$_hook"
done