linux-yocto/scripts/extract-ikconfig
Dick Streefland 532cf2907a scripts/extract-ikconfig: add support for bzip2, lzma and lzo
Add support for kernels compressed with bzip2, lzma or lzo to the
extract-ikconfig script.

Fixes kernel bugzilla #19852:
https://bugzilla.kernel.org/show_bug.cgi?id=19852

Signed-off-by: Dick Streefland <dick@streefland.net>
Tested-by: Justin <jlec@gentoo.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-10-28 00:22:17 +02:00

1.6 KiB
Executable File

#!/bin/sh

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extract-ikconfig - Extract the .config file from a kernel image

This will only work when the kernel was compiled with CONFIG_IKCONFIG.

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.

(c) 2009,2010 Dick Streefland dick@streefland.net

Licensed under the terms of the GNU General Public License.

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cf1='IKCFG_ST\037\213\010' cf2='0123456789'

dump_config() { if pos=tr "$cf1\n$cf2" "\n$cf2=" < "$1" | grep -abo "^$cf2" then pos=${pos%%:*} tail -c+$(($pos+8)) "$1" | zcat > $tmp1 2> /dev/null if [ $? != 1 ] then # exit status must be 0 or 2 (trailing garbage warning) cat $tmp1 exit 0 fi fi }

try_decompress() { for pos in tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2" do pos=${pos%%:*} tail -c+$pos "$img" | $3 > $tmp2 2> /dev/null dump_config $tmp2 done }

Check invocation:

me=${0##*/} img=$1 if [ $# -ne 1 -o ! -s "$img" ] then echo "Usage: $me " >&2 exit 2 fi

Prepare temp files:

tmp1=/tmp/ikconfig$$.1 tmp2=/tmp/ikconfig$$.2 trap "rm -f $tmp1 $tmp2" 0

Initial attempt for uncompressed images or objects:

dump_config "$img"

That didn't work, so retry after decompression.

try_decompress '\037\213\010' xy gunzip 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 kernel config." >&2 exit 1