scripts/extract-ikconfig: add support for bzip2, lzma and lzo

Dick Streefland
2010-10-22T22:15:21Z

Add support for kernels compressed with bzip2, lzma or lzo to the
extract-ikconfig script.

Signed-off-by: Dick Streefland <dick@streefland.net>
Tested-by: Justin <jlec@gentoo.org>
---

scripts/extract-ikconfig | 41 +++++++++++++++++++++++++++--------------
1 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/scripts/extract-ikconfig b/scripts/extract-ikconfig
index 37f30d3..1512c0a 100755
--- a/scripts/extract-ikconfig
+++ b/scripts/extract-ikconfig
@@ -7,12 +7,10 @@
# 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, Dick Streefland <dick@streefland.net>
+# (c) 2009,2010 Dick Streefland <dick@streefland.net>
# Licensed under the terms of the GNU General Public License.
# ----------------------------------------------------------------------

-gz1='\037\213\010'
-gz2='01'
cf1='IKCFG_ST\037\213\010'
cf2='0123456789'

@@ -21,11 +19,25 @@ dump_config()
if pos=`tr "$cf1\n$cf2" "\n$cf2=" < "$1" | grep -abo "^$cf2"`
then
pos=${pos%%:*}
- tail -c+$(($pos+8)) "$1" | zcat -q
- exit 0
+ tail -c+$(($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
@@ -35,18 +47,19 @@ then
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 decompress and try again:
-tmp=/tmp/ikconfig$$
-trap "rm -f $tmp" 0
-for pos in `tr "$gz1\n$gz2" "\n$gz2=" < "$img" | grep -abo "^$gz2"`
-do
- pos=${pos%%:*}
- tail -c+$pos "$img" | zcat 2> /dev/null > $tmp
- dump_config $tmp
-done
+# 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