Initial commit

tools/pyelf/lmamove.py

@@ -0,0 +1,77 @@
+#!/usr/bin/python
+
+import re, elf, sys, os
+from optparse import OptionParser
+
+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()