Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0-only
3# ----------------------------------------------------------------------
4# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
5#
6# Inspired from extract-ikconfig
7# (c) 2009,2010 Dick Streefland <dick@streefland.net>
8#
9# (c) 2011 Corentin Chary <corentin.chary@gmail.com>
10#
11# ----------------------------------------------------------------------
12
13check_vmlinux()
14{
15 if file "$1" | grep -q 'Linux kernel.*boot executable' ||
16 readelf -h "$1" > /dev/null 2>&1
17 then
18 cat "$1"
19 exit 0
20 fi
21}
22
23try_decompress()
24{
25 # The obscure use of the "tr" filter is to work around older versions of
26 # "grep" that report the byte offset of the line instead of the pattern.
27
28 # Try to find the header ($1) and decompress from here
29 for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
30 do
31 pos=${pos%%:*}
32 tail -c+$pos "$img" | $3 > $tmp 2> /dev/null
33 check_vmlinux $tmp
34 done
35}
36
37# Check invocation:
38me=${0##*/}
39img=$1
40if [ $# -ne 1 -o ! -s "$img" ]
41then
42 echo "Usage: $me <kernel-image>" >&2
43 exit 2
44fi
45
46# Prepare temp files:
47tmp=$(mktemp /tmp/vmlinux-XXX)
48trap "rm -f $tmp" 0
49
50# That didn't work, so retry after decompression.
51try_decompress '\037\213\010' xy gunzip
52try_decompress '\3757zXZ\000' abcde unxz
53try_decompress 'BZh' xy bunzip2
54try_decompress '\135\0\0\0' xxx unlzma
55try_decompress '\211\114\132' xy 'lzop -d'
56try_decompress '\002!L\030' xxx 'lz4 -d'
57try_decompress '(\265/\375' xxx unzstd
58
59# Finally check for uncompressed images or objects:
60check_vmlinux $img
61
62# Bail out:
63echo "$me: Cannot find vmlinux." >&2