Commit 09d48127 authored by Corentin Chary's avatar Corentin Chary Committed by Michal Marek

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)

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: default avatarCorentin Chary <>
Signed-off-by: default avatarMichal Marek <>
parent 322a8b03
# ----------------------------------------------------------------------
# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
# Inspired from extract-ikconfig
# (c) 2009,2010 Dick Streefland <>
# (c) 2011 Corentin Chary <>
# Licensed under the GNU General Public License, version 2 (GPLv2).
# ----------------------------------------------------------------------
# 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
# 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 "^$2"`
tail -c+$pos "$img" | $3 > $tmp 2> /dev/null
check_vmlinux $tmp
# Check invocation:
if [ $# -ne 1 -o ! -s "$img" ]
echo "Usage: $me <kernel-image>" >&2
exit 2
# Prepare temp files:
tmp=$(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
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment