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#!/usr/bin/python
# vim: set fileencoding=utf-8 :
#
# (C) 2011 Guido Guenther <agx@sigxcpu.org>
# 2011 Christoph Göhre <chris@sigxcpu.org>
#
# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Extract kernel and initramfs from a tip22 ECOFF boot image
import re
import subprocess
import sys
from optparse import OptionParser
OBJDUMP="/usr/bin/objdump"
BLOCKSIZE=4096
def extract_blob(binary, vma, offset, start, end, out):
fs = offset + start - vma
length = end - start
b = file(binary, 'rb')
o = file(out, 'wb')
b.seek(fs)
print "In: %s, length: %d, out: %s" % (binary, length, out)
while length > 0:
l = [length, BLOCKSIZE][length > BLOCKSIZE]
data = b.read(l)
o.write(data)
length -= BLOCKSIZE
b.close()
o.close()
def parse_objdump_headers(image):
"""Determine vma and offset"""
segment_re = re.compile(".* \.data\s+[0-9a-f]{8}\s+(?P<vma>[0-9a-f]{8})\s+[0-9a-f]{8}\s+(?P<offset>[0-9a-f]{8})\s+")
vma, offset = None, None
output = subprocess.Popen([OBJDUMP, "-h", image], stdout=subprocess.PIPE).stdout
for line in output:
m = segment_re.match(line)
if m:
vma = int(m.group("vma"), 16)
offset = int(m.group("offset"), 16)
break
return (vma, offset)
def parse_objdump_symbols(image):
"""Determine kernel and initrd start and end, vma and offset"""
symbol_re = re.compile(".* [a-z] (?P<addr>[a-f0-9]{16}) .* (?P<name>__[a-z]+_(start|end))")
symbols = { "__rd_start": None,
"__rd_end": None,
"__kernel_start": None,
"__kernel_end": None, }
output = subprocess.Popen([OBJDUMP, "-t", image], stdout=subprocess.PIPE).stdout
for line in output:
m = symbol_re.match(line)
if m:
name = m.group("name")
if name in symbols:
symbols[name] = int(m.group("addr"), 16)
continue
return symbols
def main(argv):
usage = """%prog <tip22image>
%prog extracts kernel and initramfs out of a tip22 image and stores the them in
files named 'kernel.img' and 'initrd.img' respectively"""
parser = OptionParser(usage)
options, args = parser.parse_args(argv[1:])
if len(args) != 1:
parser.print_usage()
return 1
else:
image = args[0]
vma, offset = parse_objdump_headers(image)
if not vma or not offset:
print >>sys.stderr, "Couldn't parse headers."
return 1
symbols = parse_objdump_symbols(image)
print "vma: 0x%x, offset: 0x%x" % (vma, offset)
print ("__kernel_start: 0x%(__kernel_start)x\n"
"__kernel_end: 0x%(__kernel_end)x\n"
"__rd_start: 0x%(__rd_start)x\n"
"__rd_end: 0x%(__rd_end)x" % symbols)
extract_blob(image, vma, offset, symbols["__kernel_start"],
symbols["__kernel_end"],
"kernel.img")
extract_blob(image, vma, offset, symbols["__rd_start"],
symbols["__rd_end"],
"initrd.img")
return 0
if __name__ == '__main__':
sys.exit(main(sys.argv))
# vim:et:ts=4:sw=4:et:sts=4:ai:set list listchars=tab\:»·,trail\:·:
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