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>
diff --git a/scripts/extract-vmlinux b/scripts/extract-vmlinux new file mode 100755 index 0000000..5061abc --- /dev/null +++ b/scripts/extract-vmlinux
@@ -0,0 +1,62 @@ +#!/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 