usr/gen_initramfs.sh
#!/bin/sh
# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
# Copyright (C) 2006 Sam Ravnborg <sam@ravnborg.org>
#
# Released under the terms of the GNU GPL
#
# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
# the cpio archive.
# This script assumes that gen_init_cpio is located in usr/ directory
# error out on errors
set -e
usage() {
cat << EOF
Usage:
$0 [-o <file>] [-l <dep_list>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
-o <file> Create initramfs file named <file> by using gen_init_cpio
-l <dep_list> Create dependency list named <dep_list>
-u <uid> User ID to map to user ID 0 (root).
<uid> is only meaningful if <cpio_source> is a
directory. "squash" forces all files to uid 0.
-g <gid> Group ID to map to group ID 0 (root).
<gid> is only meaningful if <cpio_source> is a
directory. "squash" forces all files to gid 0.
-d <date> Use date for all file mtime values
<cpio_source> File list or directory for cpio archive.
If <cpio_source> is a .cpio file it will be used
as direct input to initramfs.
All options except -o and -l may be repeated and are interpreted
sequentially and immediately. -u and -g states are preserved across
<cpio_source> options so an explicit "-u 0 -g 0" is required
to reset the root/group mapping.
EOF
}
# awk style field access
# $1 - field number; rest is argument string
field() {
shift $1 ; echo $1
}
filetype() {
local argv1="$1"
# symlink test must come before file test
if [ -L "${argv1}" ]; then
echo "slink"
elif [ -f "${argv1}" ]; then
echo "file"
elif [ -d "${argv1}" ]; then
echo "dir"
elif [ -b "${argv1}" -o -c "${argv1}" ]; then
echo "nod"
elif [ -p "${argv1}" ]; then
echo "pipe"
elif [ -S "${argv1}" ]; then
echo "sock"
else
echo "invalid"
fi
return 0
}
print_mtime() {
local my_mtime="0"
if [ -e "$1" ]; then
my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
fi
echo "# Last modified: ${my_mtime}" >> $cpio_list
echo "" >> $cpio_list
}
list_parse() {
if [ -z "$dep_list" -o -L "$1" ]; then
return
fi
echo "$1" | sed 's/:/\\:/g; s/$/ \\/' >> $dep_list
}
# for each file print a line in following format
# <filetype> <name> <path to file> <octal mode> <uid> <gid>
# for links, devices etc the format differs. See gen_init_cpio for details
parse() {
local location="$1"
local name="/${location#${srcdir}}"
# change '//' into '/'
name=$(echo "$name" | sed -e 's://*:/:g')
local mode="$2"
local uid="$3"
local gid="$4"
local ftype=$(filetype "${location}")
# remap uid/gid to 0 if necessary
[ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
[ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0
local str="${mode} ${uid} ${gid}"
[ "${ftype}" = "invalid" ] && return 0
[ "${location}" = "${srcdir}" ] && return 0
case "${ftype}" in
"file")
str="${ftype} ${name} ${location} ${str}"
;;
"nod")
local dev="`LC_ALL=C ls -l "${location}"`"
local maj=`field 5 ${dev}`
local min=`field 6 ${dev}`
maj=${maj%,}
[ -b "${location}" ] && dev="b" || dev="c"
str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"
;;
"slink")
local target=`readlink "${location}"`
str="${ftype} ${name} ${target} ${str}"
;;
*)
str="${ftype} ${name} ${str}"
;;
esac
echo "${str}" >> $cpio_list
return 0
}
unknown_option() {
printf "ERROR: unknown option \"$arg\"\n" >&2
printf "If the filename validly begins with '-', " >&2
printf "then it must be prefixed\n" >&2
printf "by './' so that it won't be interpreted as an option." >&2
printf "\n" >&2
usage >&2
exit 1
}
header() {
printf "\n#####################\n# $1\n" >> $cpio_list
}
# process one directory (incl sub-directories)
dir_filelist() {
header "$1"
srcdir=$(echo "$1" | sed -e 's://*:/:g')
dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" | LC_ALL=C sort)
# If $dirlist is only one line, then the directory is empty
if [ "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
print_mtime "$1"
echo "${dirlist}" | \
while read x; do
list_parse $x
parse $x
done
fi
}
input_file() {
source="$1"
if [ -f "$1" ]; then
# If a regular file is specified, assume it is in
# gen_init_cpio format
header "$1"
print_mtime "$1" >> $cpio_list
cat "$1" >> $cpio_list
if [ -n "$dep_list" ]; then
echo "$1 \\" >> $dep_list
cat "$1" | while read type dir file perm ; do
if [ "$type" = "file" ]; then
echo "$file \\" >> $dep_list
fi
done
fi
elif [ -d "$1" ]; then
# If a directory is specified then add all files in it to fs
dir_filelist "$1"
else
echo " ${prog}: Cannot open '$1'" >&2
exit 1
fi
}
prog=$0
root_uid=0
root_gid=0
dep_list=
timestamp=
cpio_list=$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)
output="/dev/stdout"
trap "rm -f $cpio_list" EXIT
while [ $# -gt 0 ]; do
arg="$1"
shift
case "$arg" in
"-l") # files included in initramfs - used by kbuild
dep_list="$1"
echo "deps_initramfs := \\" > $dep_list
shift
;;
"-o") # generate cpio image named $1
output="$1"
shift
;;
"-u") # map $1 to uid=0 (root)
root_uid="$1"
[ "$root_uid" = "-1" ] && root_uid=$(id -u || echo 0)
shift
;;
"-g") # map $1 to gid=0 (root)
root_gid="$1"
[ "$root_gid" = "-1" ] && root_gid=$(id -g || echo 0)
shift
;;
"-d") # date for file mtimes
timestamp="$(date -d"$1" +%s || :)"
if test -n "$timestamp"; then
timestamp="-t $timestamp"
fi
shift
;;
"-h")
usage
exit 0
;;
*)
case "$arg" in
"-"*)
unknown_option
;;
*) # input file/dir - process it
input_file "$arg"
;;
esac
;;
esac
done
# If output_file is set we will generate cpio archive
# we are careful to delete tmp files
usr/gen_init_cpio $timestamp $cpio_list > $output