xref: /linux/usr/gen_initramfs.sh (revision 4b132aacb0768ac1e652cf517097ea6f237214b9) 
1#!/bin/sh
2# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
3# Copyright (C) 2006 Sam Ravnborg <sam@ravnborg.org>
4#
5# Released under the terms of the GNU GPL
6#
7# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
8# the cpio archive.
9# This script assumes that gen_init_cpio is located in usr/ directory
10
11# error out on errors
12set -e
13
14usage() {
15cat << EOF
16Usage:
17$0 [-o <file>] [-l <dep_list>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
18	-o <file>      Create initramfs file named <file> by using gen_init_cpio
19	-l <dep_list>  Create dependency list named <dep_list>
20	-u <uid>       User ID to map to user ID 0 (root).
21		       <uid> is only meaningful if <cpio_source> is a
22		       directory.  "squash" forces all files to uid 0.
23	-g <gid>       Group ID to map to group ID 0 (root).
24		       <gid> is only meaningful if <cpio_source> is a
25		       directory.  "squash" forces all files to gid 0.
26	-d <date>      Use date for all file mtime values
27	<cpio_source>  File list or directory for cpio archive.
28		       If <cpio_source> is a .cpio file it will be used
29		       as direct input to initramfs.
30
31All options except -o and -l may be repeated and are interpreted
32sequentially and immediately.  -u and -g states are preserved across
33<cpio_source> options so an explicit "-u 0 -g 0" is required
34to reset the root/group mapping.
35EOF
36}
37
38# awk style field access
39# $1 - field number; rest is argument string
40field() {
41	shift $1 ; echo $1
42}
43
44filetype() {
45	local argv1="$1"
46
47	# symlink test must come before file test
48	if [ -L "${argv1}" ]; then
49		echo "slink"
50	elif [ -f "${argv1}" ]; then
51		echo "file"
52	elif [ -d "${argv1}" ]; then
53		echo "dir"
54	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
55		echo "nod"
56	elif [ -p "${argv1}" ]; then
57		echo "pipe"
58	elif [ -S "${argv1}" ]; then
59		echo "sock"
60	else
61		echo "invalid"
62	fi
63	return 0
64}
65
66print_mtime() {
67	local my_mtime="0"
68
69	if [ -e "$1" ]; then
70		my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
71	fi
72
73	echo "# Last modified: ${my_mtime}" >> $cpio_list
74	echo "" >> $cpio_list
75}
76
77list_parse() {
78	if [ -z "$dep_list" -o -L "$1" ]; then
79		return
80	fi
81	echo "$1" | sed 's/:/\\:/g; s/$/ \\/' >> $dep_list
82}
83
84# for each file print a line in following format
85# <filetype> <name> <path to file> <octal mode> <uid> <gid>
86# for links, devices etc the format differs. See gen_init_cpio for details
87parse() {
88	local location="$1"
89	local name="/${location#${srcdir}}"
90	# change '//' into '/'
91	name=$(echo "$name" | sed -e 's://*:/:g')
92	local mode="$2"
93	local uid="$3"
94	local gid="$4"
95	local ftype=$(filetype "${location}")
96	# remap uid/gid to 0 if necessary
97	[ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
98	[ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0
99	local str="${mode} ${uid} ${gid}"
100
101	[ "${ftype}" = "invalid" ] && return 0
102	[ "${location}" = "${srcdir}" ] && return 0
103
104	case "${ftype}" in
105		"file")
106			str="${ftype} ${name} ${location} ${str}"
107			;;
108		"nod")
109			local dev="`LC_ALL=C ls -l "${location}"`"
110			local maj=`field 5 ${dev}`
111			local min=`field 6 ${dev}`
112			maj=${maj%,}
113
114			[ -b "${location}" ] && dev="b" || dev="c"
115
116			str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"
117			;;
118		"slink")
119			local target=`readlink "${location}"`
120			str="${ftype} ${name} ${target} ${str}"
121			;;
122		*)
123			str="${ftype} ${name} ${str}"
124			;;
125	esac
126
127	echo "${str}" >> $cpio_list
128
129	return 0
130}
131
132unknown_option() {
133	printf "ERROR: unknown option \"$arg\"\n" >&2
134	printf "If the filename validly begins with '-', " >&2
135	printf "then it must be prefixed\n" >&2
136	printf "by './' so that it won't be interpreted as an option." >&2
137	printf "\n" >&2
138	usage >&2
139	exit 1
140}
141
142header() {
143	printf "\n#####################\n# $1\n" >> $cpio_list
144}
145
146# process one directory (incl sub-directories)
147dir_filelist() {
148	header "$1"
149
150	srcdir=$(echo "$1" | sed -e 's://*:/:g')
151	dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" | LC_ALL=C sort)
152
153	# If $dirlist is only one line, then the directory is empty
154	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
155		print_mtime "$1"
156
157		echo "${dirlist}" | \
158		while read x; do
159			list_parse $x
160			parse $x
161		done
162	fi
163}
164
165input_file() {
166	source="$1"
167	if [ -f "$1" ]; then
168		# If a regular file is specified, assume it is in
169		# gen_init_cpio format
170		header "$1"
171		print_mtime "$1" >> $cpio_list
172		cat "$1"         >> $cpio_list
173		if [ -n "$dep_list" ]; then
174		        echo "$1 \\"  >> $dep_list
175			cat "$1" | while read type dir file perm ; do
176				if [ "$type" = "file" ]; then
177					echo "$file \\" >> $dep_list
178				fi
179			done
180		fi
181	elif [ -d "$1" ]; then
182		# If a directory is specified then add all files in it to fs
183		dir_filelist "$1"
184	else
185		echo "  ${prog}: Cannot open '$1'" >&2
186		exit 1
187	fi
188}
189
190prog=$0
191root_uid=0
192root_gid=0
193dep_list=
194timestamp=
195cpio_list=$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)
196output="/dev/stdout"
197
198trap "rm -f $cpio_list" EXIT
199
200while [ $# -gt 0 ]; do
201	arg="$1"
202	shift
203	case "$arg" in
204		"-l")	# files included in initramfs - used by kbuild
205			dep_list="$1"
206			echo "deps_initramfs := \\" > $dep_list
207			shift
208			;;
209		"-o")	# generate cpio image named $1
210			output="$1"
211			shift
212			;;
213		"-u")	# map $1 to uid=0 (root)
214			root_uid="$1"
215			[ "$root_uid" = "-1" ] && root_uid=$(id -u || echo 0)
216			shift
217			;;
218		"-g")	# map $1 to gid=0 (root)
219			root_gid="$1"
220			[ "$root_gid" = "-1" ] && root_gid=$(id -g || echo 0)
221			shift
222			;;
223		"-d")	# date for file mtimes
224			timestamp="$(date -d"$1" +%s || :)"
225			if test -n "$timestamp"; then
226				timestamp="-t $timestamp"
227			fi
228			shift
229			;;
230		"-h")
231			usage
232			exit 0
233			;;
234		*)
235			case "$arg" in
236				"-"*)
237					unknown_option
238					;;
239				*)	# input file/dir - process it
240					input_file "$arg"
241					;;
242			esac
243			;;
244	esac
245done
246
247# If output_file is set we will generate cpio archive
248# we are careful to delete tmp files
249usr/gen_init_cpio $timestamp $cpio_list > $output
250