1*4882a593Smuzhiyun#!/bin/sh 2*4882a593Smuzhiyun# SPDX-License-Identifier: GPL-2.0-only 3*4882a593Smuzhiyun# ---------------------------------------------------------------------- 4*4882a593Smuzhiyun# extract-vmlinux - Extract uncompressed vmlinux from a kernel image 5*4882a593Smuzhiyun# 6*4882a593Smuzhiyun# Inspired from extract-ikconfig 7*4882a593Smuzhiyun# (c) 2009,2010 Dick Streefland <dick@streefland.net> 8*4882a593Smuzhiyun# 9*4882a593Smuzhiyun# (c) 2011 Corentin Chary <corentin.chary@gmail.com> 10*4882a593Smuzhiyun# 11*4882a593Smuzhiyun# ---------------------------------------------------------------------- 12*4882a593Smuzhiyun 13*4882a593Smuzhiyuncheck_vmlinux() 14*4882a593Smuzhiyun{ 15*4882a593Smuzhiyun # Use readelf to check if it's a valid ELF 16*4882a593Smuzhiyun # TODO: find a better to way to check that it's really vmlinux 17*4882a593Smuzhiyun # and not just an elf 18*4882a593Smuzhiyun readelf -h $1 > /dev/null 2>&1 || return 1 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun cat $1 21*4882a593Smuzhiyun exit 0 22*4882a593Smuzhiyun} 23*4882a593Smuzhiyun 24*4882a593Smuzhiyuntry_decompress() 25*4882a593Smuzhiyun{ 26*4882a593Smuzhiyun # The obscure use of the "tr" filter is to work around older versions of 27*4882a593Smuzhiyun # "grep" that report the byte offset of the line instead of the pattern. 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun # Try to find the header ($1) and decompress from here 30*4882a593Smuzhiyun for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"` 31*4882a593Smuzhiyun do 32*4882a593Smuzhiyun pos=${pos%%:*} 33*4882a593Smuzhiyun tail -c+$pos "$img" | $3 > $tmp 2> /dev/null 34*4882a593Smuzhiyun check_vmlinux $tmp 35*4882a593Smuzhiyun done 36*4882a593Smuzhiyun} 37*4882a593Smuzhiyun 38*4882a593Smuzhiyun# Check invocation: 39*4882a593Smuzhiyunme=${0##*/} 40*4882a593Smuzhiyunimg=$1 41*4882a593Smuzhiyunif [ $# -ne 1 -o ! -s "$img" ] 42*4882a593Smuzhiyunthen 43*4882a593Smuzhiyun echo "Usage: $me <kernel-image>" >&2 44*4882a593Smuzhiyun exit 2 45*4882a593Smuzhiyunfi 46*4882a593Smuzhiyun 47*4882a593Smuzhiyun# Prepare temp files: 48*4882a593Smuzhiyuntmp=$(mktemp /tmp/vmlinux-XXX) 49*4882a593Smuzhiyuntrap "rm -f $tmp" 0 50*4882a593Smuzhiyun 51*4882a593Smuzhiyun# That didn't work, so retry after decompression. 52*4882a593Smuzhiyuntry_decompress '\037\213\010' xy gunzip 53*4882a593Smuzhiyuntry_decompress '\3757zXZ\000' abcde unxz 54*4882a593Smuzhiyuntry_decompress 'BZh' xy bunzip2 55*4882a593Smuzhiyuntry_decompress '\135\0\0\0' xxx unlzma 56*4882a593Smuzhiyuntry_decompress '\211\114\132' xy 'lzop -d' 57*4882a593Smuzhiyuntry_decompress '\002!L\030' xxx 'lz4 -d' 58*4882a593Smuzhiyuntry_decompress '(\265/\375' xxx unzstd 59*4882a593Smuzhiyun 60*4882a593Smuzhiyun# Finally check for uncompressed images or objects: 61*4882a593Smuzhiyuncheck_vmlinux $img 62*4882a593Smuzhiyun 63*4882a593Smuzhiyun# Bail out: 64*4882a593Smuzhiyunecho "$me: Cannot find vmlinux." >&2 65