1e150869ca
When extract-vmlinux succeeds, it doesn't output which decompression method was found at which offset. Adding this additional output in check_vmlinux() helps troubleshooting and reverse-engineering images. The last check_vmlinux() call was also quoted to accept spaces. Signed-off-by: Maxime Thiebaut <maxime+kernel@thiebaut.dev> Reviewed-by: Nicolas Schier <nsc@kernel.org> Link: https://lore.kernel.org/r/X6OQ4pHdpreJtlTnf0tFEb4Uxz8T8gFv_7Yw6tpBK4ZBgHYjJr_URwUwCVynpkb-H8Yjk7DdBF01zY-sfqu_7N5trZQfcd6s_4PtdGlHtlA=@thiebaut.dev Signed-off-by: Nathan Chancellor <nathan@kernel.org>
1.7 KiB
Executable File
#!/bin/sh
SPDX-License-Identifier: GPL-2.0-only
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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
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me=${0##*/}
check_vmlinux() { if file "$1" | grep -q 'Linux kernel.*boot executable' || readelf -h "$1" > /dev/null 2>&1 then cat "$1" echo "$me: Extracted vmlinux using '$2' from offset $3" >&2 exit 0 fi }
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 "$3" $pos
done
}
Check invocation:
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 $tmp" 0
That didn't work, so retry after decompression.
try_decompress '\037\213\010' xy gunzip try_decompress '\3757zXZ\000' abcde unxz try_decompress 'BZh' xy bunzip2 try_decompress '\135\0\0\0' xxx unlzma try_decompress '\211\114\132' xy 'lzop -d' try_decompress '\002!L\030' xxx 'lz4 -d' try_decompress '(\265/\375' xxx unzstd
Finally check for uncompressed images or objects:
check_vmlinux "$img" cat 0
Bail out:
echo "$me: Cannot find vmlinux." >&2