1#!/bin/bash
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, and then compresses it.
9# The script may also be used to generate the inputfile used for gen_init_cpio
10# This script assumes that gen_init_cpio is located in usr/ directory
11
12# error out on errors
13set -e
14
15usage() {
16cat << EOF
17Usage:
18$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
19	-o <file>      Create compressed initramfs file named <file> using
20		       gen_init_cpio and compressor depending on the extension
21	-u <uid>       User ID to map to user ID 0 (root).
22		       <uid> is only meaningful if <cpio_source> is a
23		       directory.  "squash" forces all files to uid 0.
24	-g <gid>       Group ID to map to group ID 0 (root).
25		       <gid> is only meaningful if <cpio_source> is a
26		       directory.  "squash" forces all files to gid 0.
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	-d             Output the default cpio list.
31
32All options except -o and -l may be repeated and are interpreted
33sequentially and immediately.  -u and -g states are preserved across
34<cpio_source> options so an explicit "-u 0 -g 0" is required
35to reset the root/group mapping.
36EOF
37}
38
39# awk style field access
40# $1 - field number; rest is argument string
41field() {
42	shift $1 ; echo $1
43}
44
45list_default_initramfs() {
46	# echo usr/kinit/kinit
47	:
48}
49
50default_initramfs() {
51	cat <<-EOF >> ${output}
52		# This is a very simple, default initramfs
53
54		dir /dev 0755 0 0
55		nod /dev/console 0600 0 0 c 5 1
56		dir /root 0700 0 0
57		# file /kinit usr/kinit/kinit 0755 0 0
58		# slink /init kinit 0755 0 0
59	EOF
60}
61
62filetype() {
63	local argv1="$1"
64
65	# symlink test must come before file test
66	if [ -L "${argv1}" ]; then
67		echo "slink"
68	elif [ -f "${argv1}" ]; then
69		echo "file"
70	elif [ -d "${argv1}" ]; then
71		echo "dir"
72	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
73		echo "nod"
74	elif [ -p "${argv1}" ]; then
75		echo "pipe"
76	elif [ -S "${argv1}" ]; then
77		echo "sock"
78	else
79		echo "invalid"
80	fi
81	return 0
82}
83
84list_print_mtime() {
85	:
86}
87
88print_mtime() {
89	local my_mtime="0"
90
91	if [ -e "$1" ]; then
92		my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
93	fi
94
95	echo "# Last modified: ${my_mtime}" >> ${output}
96	echo "" >> ${output}
97}
98
99list_parse() {
100	[ ! -L "$1" ] && echo "$1 \\" || :
101}
102
103# for each file print a line in following format
104# <filetype> <name> <path to file> <octal mode> <uid> <gid>
105# for links, devices etc the format differs. See gen_init_cpio for details
106parse() {
107	local location="$1"
108	local name="${location/${srcdir}//}"
109	# change '//' into '/'
110	name="${name//\/\///}"
111	local mode="$2"
112	local uid="$3"
113	local gid="$4"
114	local ftype=$(filetype "${location}")
115	# remap uid/gid to 0 if necessary
116	[ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
117	[ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0
118	local str="${mode} ${uid} ${gid}"
119
120	[ "${ftype}" == "invalid" ] && return 0
121	[ "${location}" == "${srcdir}" ] && return 0
122
123	case "${ftype}" in
124		"file")
125			str="${ftype} ${name} ${location} ${str}"
126			;;
127		"nod")
128			local dev=`LC_ALL=C ls -l "${location}"`
129			local maj=`field 5 ${dev}`
130			local min=`field 6 ${dev}`
131			maj=${maj%,}
132
133			[ -b "${location}" ] && dev="b" || dev="c"
134
135			str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"
136			;;
137		"slink")
138			local target=`readlink "${location}"`
139			str="${ftype} ${name} ${target} ${str}"
140			;;
141		*)
142			str="${ftype} ${name} ${str}"
143			;;
144	esac
145
146	echo "${str}" >> ${output}
147
148	return 0
149}
150
151unknown_option() {
152	printf "ERROR: unknown option \"$arg\"\n" >&2
153	printf "If the filename validly begins with '-', " >&2
154	printf "then it must be prefixed\n" >&2
155	printf "by './' so that it won't be interpreted as an option." >&2
156	printf "\n" >&2
157	usage >&2
158	exit 1
159}
160
161list_header() {
162	:
163}
164
165header() {
166	printf "\n#####################\n# $1\n" >> ${output}
167}
168
169# process one directory (incl sub-directories)
170dir_filelist() {
171	${dep_list}header "$1"
172
173	srcdir=$(echo "$1" | sed -e 's://*:/:g')
174	dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n")
175
176	# If $dirlist is only one line, then the directory is empty
177	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
178		${dep_list}print_mtime "$1"
179
180		echo "${dirlist}" | \
181		while read x; do
182			${dep_list}parse ${x}
183		done
184	fi
185}
186
187# if only one file is specified and it is .cpio file then use it direct as fs
188# if a directory is specified then add all files in given direcotry to fs
189# if a regular file is specified assume it is in gen_initramfs format
190input_file() {
191	source="$1"
192	if [ -f "$1" ]; then
193		${dep_list}header "$1"
194		is_cpio="$(echo "$1" | sed 's/^.*\.cpio\(\..*\)\?/cpio/')"
195		if [ $2 -eq 0 -a ${is_cpio} == "cpio" ]; then
196			cpio_file=$1
197			echo "$1" | grep -q '^.*\.cpio\..*' && is_cpio_compressed="compressed"
198			[ ! -z ${dep_list} ] && echo "$1"
199			return 0
200		fi
201		if [ -z ${dep_list} ]; then
202			print_mtime "$1" >> ${output}
203			cat "$1"         >> ${output}
204		else
205		        echo "$1 \\"
206			cat "$1" | while read type dir file perm ; do
207				if [ "$type" == "file" ]; then
208					echo "$file \\";
209				fi
210			done
211		fi
212	elif [ -d "$1" ]; then
213		dir_filelist "$1"
214	else
215		echo "  ${prog}: Cannot open '$1'" >&2
216		exit 1
217	fi
218}
219
220prog=$0
221root_uid=0
222root_gid=0
223dep_list=
224cpio_file=
225cpio_list=
226output="/dev/stdout"
227output_file=""
228is_cpio_compressed=
229compr="gzip -9 -f"
230
231arg="$1"
232case "$arg" in
233	"-l")	# files included in initramfs - used by kbuild
234		dep_list="list_"
235		echo "deps_initramfs := $0 \\"
236		shift
237		;;
238	"-o")	# generate compressed cpio image named $1
239		shift
240		output_file="$1"
241		cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
242		output=${cpio_list}
243		echo "$output_file" | grep -q "\.gz$" && compr="gzip -9 -f"
244		echo "$output_file" | grep -q "\.bz2$" && compr="bzip2 -9 -f"
245		echo "$output_file" | grep -q "\.lzma$" && compr="lzma -9 -f"
246		echo "$output_file" | grep -q "\.xz$" && \
247				compr="xz --check=crc32 --lzma2=dict=1MiB"
248		echo "$output_file" | grep -q "\.lzo$" && compr="lzop -9 -f"
249		echo "$output_file" | grep -q "\.cpio$" && compr="cat"
250		shift
251		;;
252esac
253while [ $# -gt 0 ]; do
254	arg="$1"
255	shift
256	case "$arg" in
257		"-u")	# map $1 to uid=0 (root)
258			root_uid="$1"
259			shift
260			;;
261		"-g")	# map $1 to gid=0 (root)
262			root_gid="$1"
263			shift
264			;;
265		"-d")	# display default initramfs list
266			default_list="$arg"
267			${dep_list}default_initramfs
268			;;
269		"-h")
270			usage
271			exit 0
272			;;
273		*)
274			case "$arg" in
275				"-"*)
276					unknown_option
277					;;
278				*)	# input file/dir - process it
279					input_file "$arg" "$#"
280					;;
281			esac
282			;;
283	esac
284done
285
286# If output_file is set we will generate cpio archive and compress it
287# we are careful to delete tmp files
288if [ ! -z ${output_file} ]; then
289	if [ -z ${cpio_file} ]; then
290		cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"
291		usr/gen_init_cpio ${cpio_list} > ${cpio_tfile}
292	else
293		cpio_tfile=${cpio_file}
294	fi
295	rm ${cpio_list}
296	if [ "${is_cpio_compressed}" = "compressed" ]; then
297		cat ${cpio_tfile} > ${output_file}
298	else
299		(cat ${cpio_tfile} | ${compr}  - > ${output_file}) \
300		|| (rm -f ${output_file} ; false)
301	fi
302	[ -z ${cpio_file} ] && rm ${cpio_tfile}
303fi
304exit 0
305