[deliverable/linux.git] / scripts / extract-vmlinux

#!/bin/sh
# ----------------------------------------------------------------------
# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
#
# Inspired from extract-ikconfig
# (c) 2009,2010 Dick Streefland <dick@streefland.net>
#
# (c) 2011      Corentin Chary <corentin.chary@gmail.com>
#
# Licensed under the GNU General Public License, version 2 (GPLv2).
# ----------------------------------------------------------------------

check_vmlinux()
{
	# Use readelf to check if it's a valid ELF
	# TODO: find a better to way to check that it's really vmlinux
	#       and not just an elf
	readelf -h $1 > /dev/null 2>&1 || return 1

	cat $1
	exit 0
}

try_decompress()
{
	# The obscure use of the "tr" filter is to work around older versions of
	# "grep" that report the byte offset of the line instead of the pattern.

	# Try to find the header ($1) and decompress from here
	for	pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
	do
		pos=${pos%%:*}
		tail -c+$pos "$img" | $3 > $tmp 2> /dev/null
		check_vmlinux $tmp
	done
}

# Check invocation:
me=${0##*/}
img=$1
if	[ $# -ne 1 -o ! -s "$img" ]
then
	echo "Usage: $me <kernel-image>" >&2
	exit 2
fi

# Prepare temp files:
tmp=$(mktemp /tmp/vmlinux-XXX)
trap "rm -f $tmp" 0

# Initial attempt for uncompressed images or objects:
check_vmlinux $img

# That didn't work, so retry after decompression.
try_decompress '\037\213\010' xy    gunzip
try_decompress '\3757zXZ\000' abcde unxz
try_decompress 'BZh'          xy    bunzip2
try_decompress '\135\0\0\0'   xxx   unlzma
try_decompress '\211\114\132' xy    'lzop -d'

# Bail out:
echo "$me: Cannot find vmlinux." >&2
Commit	Line	Data
09d48127 CC	1	#!/bin/sh
	2	# ----------------------------------------------------------------------
	3	# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
	4	#
	5	# Inspired from extract-ikconfig
	6	# (c) 2009,2010 Dick Streefland <dick@streefland.net>
	7	#
	8	# (c) 2011 Corentin Chary <corentin.chary@gmail.com>
	9	#
	10	# Licensed under the GNU General Public License, version 2 (GPLv2).
	11	# ----------------------------------------------------------------------
	12
	13	check_vmlinux()
	14	{
	15	# Use readelf to check if it's a valid ELF
	16	# TODO: find a better to way to check that it's really vmlinux
	17	# and not just an elf
	18	readelf -h $1 > /dev/null 2>&1 \|\| return 1
	19
	20	cat $1
	21	exit 0
	22	}
	23
	24	try_decompress()
	25	{
	26	# The obscure use of the "tr" filter is to work around older versions of
	27	# "grep" that report the byte offset of the line instead of the pattern.
	28
	29	# Try to find the header ($1) and decompress from here
	30	for pos in `tr "$1\n$2" "\n$2=" < "$img" \| grep -abo "^$2"`
	31	do
	32	pos=${pos%%:*}
	33	tail -c+$pos "$img" \| $3 > $tmp 2> /dev/null
	34	check_vmlinux $tmp
	35	done
	36	}
	37
	38	# Check invocation:
	39	me=${0##*/}
	40	img=$1
	41	if [ $# -ne 1 -o ! -s "$img" ]
	42	then
	43	echo "Usage: $me <kernel-image>" >&2
	44	exit 2
	45	fi
	46
	47	# Prepare temp files:
	48	tmp=$(mktemp /tmp/vmlinux-XXX)
	49	trap "rm -f $tmp" 0
	50
	51	# Initial attempt for uncompressed images or objects:
	52	check_vmlinux $img
	53
	54	# That didn't work, so retry after decompression.
	55	try_decompress '\037\213\010' xy gunzip
	56	try_decompress '\3757zXZ\000' abcde unxz
	57	try_decompress 'BZh' xy bunzip2
	58	try_decompress '\135\0\0\0' xxx unlzma
	59	try_decompress '\211\114\132' xy 'lzop -d'
	60
	61	# Bail out:
	62	echo "$me: Cannot find vmlinux." >&2