Subversion Repositories c0or1k

#!/usr/bin/python

import re, elf, sys, os

from optparse import OptionParser

# May need to do something about this

toolprefix = "arm-none-linux-gnueabi-"

objdump = toolprefix + "objdump"

objcopy = toolprefix + "objcopy"

readelf = toolprefix + "readelf"

egrep = "egrep"

snames_file = "section_names.txt"

def get_section_names(path):

        rest, filename = os.path.split(path)

        sections = []

        os.system(readelf + " -l " + path + " > readelf.out")

        os.system(egrep + r' "(\.){1}(\w){1}" ' + " readelf.out > sections.out")

        for line in file('sections.out'):

                secnum, secname = str.split(line)

                sections.append((secnum,secname))

        print "Sections:\n" + str(sections)

        return sections

helpmsg = \

'''Usage:

        lmamove.py <filename> <[<op>]offset>

        Where <filename> is the file to modify, <offset> is the offset to be added,

        subtracted or assigned, depending on the <op>, which can be either + or -

        !!! NOTE THIS TOOL IS NOT VERY USEFUL BECAUSE IT TURNS OUT THAT SOME SECTIONS

        ARE LIKELY TO BE PUT TOGETHER INTO THE SAME SEGMENT. For example (.text with .rodata)

        and (.data with .bss) Therefore moving one sectoin's LMA confuses what to do with the

        other section. The segment layout is almost always not same as initial after LMA

        modification with objcopy. !!!

'''

def check_args():

        if len(sys.argv) < 3:

                print helpmsg

                sys.exit()

        filename = sys.argv[1]

        if not os.path.exists(filename):

                print "Given path: " + filename + " does not exist.\n"

                sys.exit()

def move_sections(path, sections, op, offset):

        for secnum, secname in sections:

                os.system(objcopy + " --change-section-lma " + secname + op + offset + " " + path)

def lmamove():

        '''

        Moves an ARM ELF executable's LMA by moving each of its sections by

        the given offset. It uses binutils (namely readelf and objcopy) to do

        the actual work. Normally objcopy supports a similar operation; moving

        of VMA of the whole program by --adjust-vma switch. But it only supports

        modifying LMAs by section. Therefore this script extracts all loadable

        section names and moves them one by one in order to move the whole program.

        '''

        check_args()

        filename = sys.argv[1]

        offset = sys.argv[2]

        if offset[0] in "+-":

                op = offset[0]

                offset = offset[1:]

        else:

                op = "+"

        if offset[:1] == "0x":

                offset = int(offset, 16)

        section_names = get_section_names(filename)

        move_sections(filename, section_names, op, offset)

        print("Done.\n")

if __name__ == "__main__":

        lmamove()