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-rwxr-xr-xscripts/extract-ikconfig127
1 files changed, 44 insertions, 83 deletions
diff --git a/scripts/extract-ikconfig b/scripts/extract-ikconfig
index de233ff..37f30d3 100755
--- a/scripts/extract-ikconfig
+++ b/scripts/extract-ikconfig
@@ -1,92 +1,53 @@
#!/bin/sh
-# extracts .config info from a [b]zImage file
-# uses: binoffset (new), dd, zcat, strings, grep
-# $arg1 is [b]zImage filename
-
-binoffset="./scripts/binoffset"
-test -e $binoffset || cc -o $binoffset ./scripts/binoffset.c || exit 1
-
-IKCFG_ST="0x49 0x4b 0x43 0x46 0x47 0x5f 0x53 0x54"
-IKCFG_ED="0x49 0x4b 0x43 0x46 0x47 0x5f 0x45 0x44"
-dump_config() {
- file="$1"
-
- start=`$binoffset $file $IKCFG_ST 2>/dev/null`
- [ "$?" != "0" ] && start="-1"
- if [ "$start" -eq "-1" ]; then
- return
- fi
- end=`$binoffset $file $IKCFG_ED 2>/dev/null`
- [ "$?" != "0" ] && end="-1"
- if [ "$end" -eq "-1" ]; then
- return
- fi
-
- start=`expr $start + 8`
- size=`expr $end - $start`
-
- dd if="$file" ibs=1 skip="$start" count="$size" 2>/dev/null | zcat
-
- clean_up
- exit 0
-}
-
-
-usage()
-{
- echo " usage: extract-ikconfig [b]zImage_filename"
-}
-
-clean_up()
+# ----------------------------------------------------------------------
+# 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, 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'
+
+dump_config()
{
- if [ "$TMPFILE" != "" ]; then
- rm -f $TMPFILE
+ if pos=`tr "$cf1\n$cf2" "\n$cf2=" < "$1" | grep -abo "^$cf2"`
+ then
+ pos=${pos%%:*}
+ tail -c+$(($pos+8)) "$1" | zcat -q
+ exit 0
fi
}
-if [ $# -lt 1 ]
+# Check invocation:
+me=${0##*/}
+img=$1
+if [ $# -ne 1 -o ! -s "$img" ]
then
- usage
- exit 1
+ echo "Usage: $me <kernel-image>" >&2
+ exit 2
fi
-TMPFILE=`mktemp -t ikconfig-XXXXXX` || exit 1
-image="$1"
-
-# vmlinux: Attempt to dump the configuration from the file directly
-dump_config "$image"
-
-GZHDR1="0x1f 0x8b 0x08 0x00"
-GZHDR2="0x1f 0x8b 0x08 0x08"
-
-ELFHDR="0x7f 0x45 0x4c 0x46"
-
-# vmlinux.gz: Check for a compressed images
-off=`$binoffset "$image" $GZHDR1 2>/dev/null`
-[ "$?" != "0" ] && off="-1"
-if [ "$off" -eq "-1" ]; then
- off=`$binoffset "$image" $GZHDR2 2>/dev/null`
- [ "$?" != "0" ] && off="-1"
-fi
-if [ "$off" -eq "0" ]; then
- zcat <"$image" >"$TMPFILE"
- dump_config "$TMPFILE"
-elif [ "$off" -ne "-1" ]; then
- (dd ibs="$off" skip=1 count=0 && dd bs=512k) <"$image" 2>/dev/null | \
- zcat >"$TMPFILE"
- dump_config "$TMPFILE"
-
-# check if this is simply an ELF file
-else
- off=`$binoffset "$image" $ELFHDR 2>/dev/null`
- [ "$?" != "0" ] && off="-1"
- if [ "$off" -eq "0" ]; then
- dump_config "$image"
- fi
-fi
-
-echo "ERROR: Unable to extract kernel configuration information."
-echo " This kernel image may not have the config info."
-
-clean_up
+# 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 $tmp
+done
+
+# Bail out:
+echo "$me: Cannot find kernel config." >&2
exit 1
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