Linux-2.6.12-rc2
[linux-2.6.git] / scripts / extract-ikconfig
1 #!/bin/sh
2 # extracts .config info from a [b]zImage file
3 # uses: binoffset (new), dd, zcat, strings, grep
4 # $arg1 is [b]zImage filename
5
6 binoffset="./scripts/binoffset"
7
8 IKCFG_ST="0x49 0x4b 0x43 0x46 0x47 0x5f 0x53 0x54"
9 IKCFG_ED="0x49 0x4b 0x43 0x46 0x47 0x5f 0x45 0x44"
10 function dump_config {
11     typeset file="$1"
12
13     start=`$binoffset $file $IKCFG_ST 2>/dev/null`
14     [ "$?" != "0" ] && start="-1"
15     if [ "$start" -eq "-1" ]; then
16         return
17     fi
18     end=`$binoffset $file $IKCFG_ED 2>/dev/null`
19
20     let start="$start + 8"
21     let size="$end - $start"
22
23     head --bytes="$end" "$file" | tail --bytes="$size" | zcat
24
25     clean_up
26     exit 0
27 }
28
29
30 usage()
31 {
32         echo "  usage: extract-ikconfig [b]zImage_filename"
33 }
34
35 clean_up()
36 {
37         if [ "$TMPFILE" != "" ]; then
38                 rm -f $TMPFILE
39         fi
40 }
41
42 if [ $# -lt 1 ]
43 then
44         usage
45         exit 1
46 fi
47
48 TMPFILE="/tmp/ikconfig-$$"
49 image="$1"
50
51 # vmlinux: Attempt to dump the configuration from the file directly
52 dump_config "$image"
53
54 GZHDR1="0x1f 0x8b 0x08 0x00"
55 GZHDR2="0x1f 0x8b 0x08 0x08"
56
57 # vmlinux.gz: Check for a compressed images
58 off=`$binoffset "$image" $GZHDR1 2>/dev/null`
59 [ "$?" != "0" ] && off="-1"
60 if [ "$off" -eq "-1" ]; then
61         off=`$binoffset "$image" $GZHDR2 2>/dev/null`
62         [ "$?" != "0" ] && off="-1"
63 fi
64 if [ "$off" -eq "0" ]; then
65         zcat <"$image" >"$TMPFILE"
66         dump_config "$TMPFILE"
67 elif [ "$off" -ne "-1" ]; then
68         (dd ibs="$off" skip=1 count=0 && dd bs=512k) <"$image" 2>/dev/null | \
69                 zcat >"$TMPFILE"
70         dump_config "$TMPFILE"
71 fi
72
73 echo "ERROR: Unable to extract kernel configuration information."
74 echo "       This kernel image may not have the config info."
75
76 clean_up
77 exit 1