2 # ----------------------------------------------------------------------
3 # extract-ikconfig - Extract the .config file from a kernel image
5 # This will only work when the kernel was compiled with CONFIG_IKCONFIG.
7 # The obscure use of the "tr" filter is to work around older versions of
8 # "grep" that report the byte offset of the line instead of the pattern.
10 # (c) 2009,2010 Dick Streefland <dick@streefland.net>
11 # Licensed under the terms of the GNU General Public License.
12 # ----------------------------------------------------------------------
14 cf1='IKCFG_ST\037\213\010'
19 if pos=`tr "$cf1\n$cf2" "\n$cf2=" < "$1" | grep -abo "^$cf2"`
22 tail -c+$(($pos+8)) "$1" | zcat > $tmp1 2> /dev/null
24 then # exit status must be 0 or 2 (trailing garbage warning)
33 for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
36 tail -c+$pos "$img" | $3 > $tmp2 2> /dev/null
44 if [ $# -ne 1 -o ! -s "$img" ]
46 echo "Usage: $me <kernel-image>" >&2
51 tmp1=/tmp/ikconfig$$.1
52 tmp2=/tmp/ikconfig$$.2
53 trap "rm -f $tmp1 $tmp2" 0
55 # Initial attempt for uncompressed images or objects:
58 # That didn't work, so retry after decompression.
59 try_decompress '\037\213\010' xy gunzip
60 try_decompress '\3757zXZ\000' abcde unxz
61 try_decompress 'BZh' xy bunzip2
62 try_decompress '\135\0\0\0' xxx unlzma
63 try_decompress '\211\114\132' xy 'lzop -d'
66 echo "$me: Cannot find kernel config." >&2