linux-yocto/scripts/extract-vmlinux
Corentin Chary 09d481270d scripts: add extract-vmlinux
This script can be used to extract vmlinux from a compressed
kernel image (bzImage, etc..). It's inspired from (a subset of)
extract-ikconfig.

It's something a lot of people have been looking for (mainly
people with xen < 4 that doesn't support bzImages at all).

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-08-31 16:12:17 +02:00

1.6 KiB
Executable File

#!/bin/sh

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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).

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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 " >&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