kconfig: simplification of scripts/extract-ikconfig

I've rewritten the extract-ikconfig script to extract the kernel
configuration from a kernel compiled with CONFIG_IKCONFIG. The main
motivation for the rewrite was to remove the dependency on the
external C program binoffset.c, which is compiled on the initial run.

The binoffset executable is invoked with a relative path, which means
that the old script can only be run from the top of the kernel tree,
and only when you have write permission in the scripts directory.

The new script uses tr/grep/tail/zcat only, and can be invoked from
anywhere. The binoffset.c program has been removed. This script
requires GNU grep 2.5 (released 2002-03-13) or higher, because the -o
option was introduced in that version.

Signed-off-by: Dick Streefland <dick@streefland.net>
LKML-Reference: <20091006203540.GA14634@streefland.net>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Dick Streefland 2009-10-06 22:35:40 +02:00 committed by Steven Rostedt
parent 0eca52a927
commit 7b76bfc867
4 changed files with 40 additions and 244 deletions

View File

@ -68,7 +68,6 @@ autoconf.h*
bbootsect
bin2c
binkernel.spec
binoffset
bootsect
bounds.h
bsetup

1
scripts/.gitignore vendored
View File

@ -6,5 +6,4 @@ kallsyms
pnmtologo
bin2c
unifdef
binoffset
ihex2fw

View File

@ -1,163 +0,0 @@
/***************************************************************************
* binoffset.c
* (C) 2002 Randy Dunlap <rdunlap@xenotime.net>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
# binoffset.c:
# - searches a (binary) file for a specified (binary) pattern
# - returns the offset of the located pattern or ~0 if not found
# - exits with exit status 0 normally or non-0 if pattern is not found
# or any other error occurs.
****************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#define VERSION "0.1"
#define BUF_SIZE (16 * 1024)
#define PAT_SIZE 100
char *progname;
char *inputname;
int inputfd;
unsigned int bix; /* buf index */
unsigned char patterns [PAT_SIZE] = {0}; /* byte-sized pattern array */
int pat_len; /* actual number of pattern bytes */
unsigned char *madr; /* mmap address */
size_t filesize;
int num_matches = 0;
off_t firstloc = 0;
void usage (void)
{
fprintf (stderr, "%s ver. %s\n", progname, VERSION);
fprintf (stderr, "usage: %s filename pattern_bytes\n",
progname);
fprintf (stderr, " [prints location of pattern_bytes in file]\n");
exit (1);
}
void get_pattern (int pat_count, char *pats [])
{
int ix, err, tmp;
#ifdef DEBUG
fprintf (stderr,"get_pattern: count = %d\n", pat_count);
for (ix = 0; ix < pat_count; ix++)
fprintf (stderr, " pat # %d: [%s]\n", ix, pats[ix]);
#endif
for (ix = 0; ix < pat_count; ix++) {
tmp = 0;
err = sscanf (pats[ix], "%5i", &tmp);
if (err != 1 || tmp > 0xff) {
fprintf (stderr, "pattern or value error in pattern # %d [%s]\n",
ix, pats[ix]);
usage ();
}
patterns [ix] = tmp;
}
pat_len = pat_count;
}
void search_pattern (void)
{
for (bix = 0; bix < filesize; bix++) {
if (madr[bix] == patterns[0]) {
if (memcmp (&madr[bix], patterns, pat_len) == 0) {
if (num_matches == 0)
firstloc = bix;
num_matches++;
}
}
}
}
#ifdef NOTDEF
size_t get_filesize (int fd)
{
off_t end_off = lseek (fd, 0, SEEK_END);
lseek (fd, 0, SEEK_SET);
return (size_t) end_off;
}
#endif
size_t get_filesize (int fd)
{
int err;
struct stat stat;
err = fstat (fd, &stat);
fprintf (stderr, "filesize: %ld\n", err < 0 ? (long)err : stat.st_size);
if (err < 0)
return err;
return (size_t) stat.st_size;
}
int main (int argc, char *argv [])
{
progname = argv[0];
if (argc < 3)
usage ();
get_pattern (argc - 2, argv + 2);
inputname = argv[1];
inputfd = open (inputname, O_RDONLY);
if (inputfd == -1) {
fprintf (stderr, "%s: cannot open '%s'\n",
progname, inputname);
exit (3);
}
filesize = get_filesize (inputfd);
madr = mmap (0, filesize, PROT_READ, MAP_PRIVATE, inputfd, 0);
if (madr == MAP_FAILED) {
fprintf (stderr, "mmap error = %d\n", errno);
close (inputfd);
exit (4);
}
search_pattern ();
if (munmap (madr, filesize))
fprintf (stderr, "munmap error = %d\n", errno);
if (close (inputfd))
fprintf (stderr, "%s: error %d closing '%s'\n",
progname, errno, inputname);
fprintf (stderr, "number of pattern matches = %d\n", num_matches);
if (num_matches == 0)
firstloc = ~0;
printf ("%ld\n", firstloc);
fprintf (stderr, "%ld\n", firstloc);
exit (num_matches ? 0 : 2);
}
/* end binoffset.c */

View File

@ -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
# ----------------------------------------------------------------------
# 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.
# ----------------------------------------------------------------------
binoffset="./scripts/binoffset"
test -e $binoffset || cc -o $binoffset ./scripts/binoffset.c || exit 1
gz1='\037\213\010'
gz2='01'
cf1='IKCFG_ST\037\213\010'
cf2='0123456789'
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()
dump_config()
{
echo " usage: extract-ikconfig [b]zImage_filename"
}
clean_up()
{
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="$1"
# Initial attempt for uncompressed images or objects:
dump_config "$img"
# vmlinux: Attempt to dump the configuration from the file directly
dump_config "$image"
# 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 $tmp
done
GZHDR1="0x1f 0x8b 0x08 0x00"
GZHDR2="0x1f 0x8b 0x08 0x08"
ELFHDR="0x7f 0x45 0x4c 0x46"
# vmlinux.gz: Check for a compressed images
off=`$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
# Bail out:
echo "$me: Cannot find kernel config." >&2
exit 1