forked from mirrors/linux
99b2cdde83
Support for kernel image LZ4 compression was added around 3.11, but not the corresponding kernel .config extraction. This makes possible extracting the kernel config for LZ4-compressed kernels you're not running, or the current LZ4-compressed kernel if compiled without /proc/config.gz support. Signed-off-by: Alex Pilon <alp+linux@alexpilon.ca> Signed-off-by: Michal Marek <mmarek@suse.cz>
68 lines
1.7 KiB
Bash
Executable file
68 lines
1.7 KiB
Bash
Executable file
#!/bin/sh
|
|
# ----------------------------------------------------------------------
|
|
# 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.
|
|
# ----------------------------------------------------------------------
|
|
|
|
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 <kernel-image>" >&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 '\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\041\114\030' xyy 'lz4 -d -l'
|
|
|
|
# Bail out:
|
|
echo "$me: Cannot find kernel config." >&2
|
|
exit 1
|