xref: /linux/usr/gen_initramfs.sh (revision 23c48a124b469cee2eb0c75e6d22d366d1caa118) 
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	<cpio_source>  File list or directory for cpio archive.
27		       If <cpio_source> is a .cpio file it will be used
28		       as direct input to initramfs.
29
30All options except -o and -l may be repeated and are interpreted
31sequentially and immediately.  -u and -g states are preserved across
32<cpio_source> options so an explicit "-u 0 -g 0" is required
33to reset the root/group mapping.
34EOF
35}
36
37# awk style field access
38# $1 - field number; rest is argument string
39field() {
40	shift $1 ; echo $1
41}
42
43filetype() {
44	local argv1="$1"
45
46	# symlink test must come before file test
47	if [ -L "${argv1}" ]; then
48		echo "slink"
49	elif [ -f "${argv1}" ]; then
50		echo "file"
51	elif [ -d "${argv1}" ]; then
52		echo "dir"
53	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
54		echo "nod"
55	elif [ -p "${argv1}" ]; then
56		echo "pipe"
57	elif [ -S "${argv1}" ]; then
58		echo "sock"
59	else
60		echo "invalid"
61	fi
62	return 0
63}
64
65print_mtime() {
66	local my_mtime="0"
67
68	if [ -e "$1" ]; then
69		my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
70	fi
71
72	echo "# Last modified: ${my_mtime}" >> $cpio_list
73	echo "" >> $cpio_list
74}
75
76list_parse() {
77	if [ -z "$dep_list" -o -L "$1" ]; then
78		return
79	fi
80	echo "$1" | sed 's/:/\\:/g; s/$/ \\/' >> $dep_list
81}
82
83# for each file print a line in following format
84# <filetype> <name> <path to file> <octal mode> <uid> <gid>
85# for links, devices etc the format differs. See gen_init_cpio for details
86parse() {
87	local location="$1"
88	local name="/${location#${srcdir}}"
89	# change '//' into '/'
90	name=$(echo "$name" | sed -e 's://*:/:g')
91	local mode="$2"
92	local uid="$3"
93	local gid="$4"
94	local ftype=$(filetype "${location}")
95	# remap uid/gid to 0 if necessary
96	[ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
97	[ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0
98	local str="${mode} ${uid} ${gid}"
99
100	[ "${ftype}" = "invalid" ] && return 0
101	[ "${location}" = "${srcdir}" ] && return 0
102
103	case "${ftype}" in
104		"file")
105			str="${ftype} ${name} ${location} ${str}"
106			;;
107		"nod")
108			local dev="`LC_ALL=C ls -l "${location}"`"
109			local maj=`field 5 ${dev}`
110			local min=`field 6 ${dev}`
111			maj=${maj%,}
112
113			[ -b "${location}" ] && dev="b" || dev="c"
114
115			str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"
116			;;
117		"slink")
118			local target=`readlink "${location}"`
119			str="${ftype} ${name} ${target} ${str}"
120			;;
121		*)
122			str="${ftype} ${name} ${str}"
123			;;
124	esac
125
126	echo "${str}" >> $cpio_list
127
128	return 0
129}
130
131unknown_option() {
132	printf "ERROR: unknown option \"$arg\"\n" >&2
133	printf "If the filename validly begins with '-', " >&2
134	printf "then it must be prefixed\n" >&2
135	printf "by './' so that it won't be interpreted as an option." >&2
136	printf "\n" >&2
137	usage >&2
138	exit 1
139}
140
141header() {
142	printf "\n#####################\n# $1\n" >> $cpio_list
143}
144
145# process one directory (incl sub-directories)
146dir_filelist() {
147	header "$1"
148
149	srcdir=$(echo "$1" | sed -e 's://*:/:g')
150	dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" | LC_ALL=C sort)
151
152	# If $dirlist is only one line, then the directory is empty
153	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
154		print_mtime "$1"
155
156		echo "${dirlist}" | \
157		while read x; do
158			list_parse $x
159			parse $x
160		done
161	fi
162}
163
164input_file() {
165	source="$1"
166	if [ -f "$1" ]; then
167		# If a regular file is specified, assume it is in
168		# gen_init_cpio format
169		header "$1"
170		print_mtime "$1" >> $cpio_list
171		cat "$1"         >> $cpio_list
172		if [ -n "$dep_list" ]; then
173		        echo "$1 \\"  >> $dep_list
174			cat "$1" | while read type dir file perm ; do
175				if [ "$type" = "file" ]; then
176					echo "$file \\" >> $dep_list
177				fi
178			done
179		fi
180	elif [ -d "$1" ]; then
181		# If a directory is specified then add all files in it to fs
182		dir_filelist "$1"
183	else
184		echo "  ${prog}: Cannot open '$1'" >&2
185		exit 1
186	fi
187}
188
189prog=$0
190root_uid=0
191root_gid=0
192dep_list=
193cpio_list=$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)
194output="/dev/stdout"
195
196trap "rm -f $cpio_list" EXIT
197
198while [ $# -gt 0 ]; do
199	arg="$1"
200	shift
201	case "$arg" in
202		"-l")	# files included in initramfs - used by kbuild
203			dep_list="$1"
204			echo "deps_initramfs := \\" > $dep_list
205			shift
206			;;
207		"-o")	# generate cpio image named $1
208			output="$1"
209			shift
210			;;
211		"-u")	# map $1 to uid=0 (root)
212			root_uid="$1"
213			[ "$root_uid" = "-1" ] && root_uid=$(id -u || echo 0)
214			shift
215			;;
216		"-g")	# map $1 to gid=0 (root)
217			root_gid="$1"
218			[ "$root_gid" = "-1" ] && root_gid=$(id -g || echo 0)
219			shift
220			;;
221		"-h")
222			usage
223			exit 0
224			;;
225		*)
226			case "$arg" in
227				"-"*)
228					unknown_option
229					;;
230				*)	# input file/dir - process it
231					input_file "$arg"
232					;;
233			esac
234			;;
235	esac
236done
237
238# If output_file is set we will generate cpio archive
239# we are careful to delete tmp files
240timestamp=
241if test -n "$KBUILD_BUILD_TIMESTAMP"; then
242	timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
243	if test -n "$timestamp"; then
244		timestamp="-t $timestamp"
245	fi
246fi
247usr/gen_init_cpio $timestamp $cpio_list > $output
248