tools/layoutrom.py - seabios - Gitiles

 #!/usr/bin/env python
 # Script to analyze code and arrange ld sections.
 #
 # Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.

 import sys

 # Align 'pos' to 'alignbytes' offset
 def alignpos(pos, alignbytes):
     mask = alignbytes - 1
     return (pos + mask) & ~mask

 # LD script headers/trailers
 COMMONHEADER = """
 /* DO NOT EDIT!  This is an autogenerated file.  See tools/layoutrom.py. */
 OUTPUT_FORMAT("elf32-i386")
 OUTPUT_ARCH("i386")
 SECTIONS
 {
 """
 COMMONTRAILER = """
 }
 """


 ######################################################################
 # 16bit fixed address section fitting
 ######################################################################

 # Get the maximum start position for a list of sections that end at an
 # address.
 def getSectionsStart(sections, endaddr, minalign=1):
     totspace = 0
     for size, align, name in sections:
         if align > minalign:
             minalign = align
         totspace = alignpos(totspace, align) + size
     return (endaddr - totspace) / minalign * minalign

 # Write LD script includes for the given sections
 def outSections(file, sections):
     for size, align, name in sections:
         file.write("*(%s)\n" % (name,))

 # The 16bit code can't exceed 64K of space.
 MAXPOS = 64*1024

 # Layout the 16bit code.  This ensures sections with fixed offset
 # requirements are placed in the correct location.  It also places the
 # 16bit code as high as possible in the f-segment.
 def doLayout16(sections, outname):
     textsections = []
     rodatasections = []
     datasections = []
     # fixedsections = [(addr, sectioninfo, extasectionslist), ...]
     fixedsections = []
     # canrelocate = [(sectioninfo, list), ...]
     canrelocate = []

     # Find desired sections.
     for section in sections:
         size, align, name = section
         if name[:11] == '.fixedaddr.':
             addr = int(name[11:], 16)
             fixedsections.append((addr, section, []))
             if align != 1:
                 print "Error: Fixed section %s has non-zero alignment (%d)" % (
                     name, align)
                 sys.exit(1)
         if name[:6] == '.text.':
             textsections.append(section)
             canrelocate.append((section, textsections))
         if name[:17] == '.rodata.__func__.' or name == '.rodata.str1.1':
             rodatasections.append(section)
             #canrelocate.append((section, rodatasections))
         if name[:8] == '.data16.':
             datasections.append(section)
             #canrelocate.append((section, datasections))

     # Find freespace in fixed address area
     fixedsections.sort()
     # fixedAddr = [(freespace, sectioninfo), ...]
     fixedAddr = []
     for i in range(len(fixedsections)):
         fixedsectioninfo = fixedsections[i]
         addr, section, extrasectionslist = fixedsectioninfo
         if i == len(fixedsections) - 1:
             nextaddr = MAXPOS
         else:
             nextaddr = fixedsections[i+1][0]
         avail = nextaddr - addr - section[0]
         fixedAddr.append((avail, fixedsectioninfo))

     # Attempt to fit other sections into fixed area
     fixedAddr.sort()
     canrelocate.sort()
     totalused = 0
     for freespace, fixedsectioninfo in fixedAddr:
         fixedaddr, fixedsection, extrasections = fixedsectioninfo
         addpos = fixedaddr + fixedsection[0]
         totalused += fixedsection[0]
         nextfixedaddr = addpos + freespace
 #        print "Filling section %x uses %d, next=%x, available=%d" % (
 #            fixedaddr, fixedsection[0], nextfixedaddr, freespace)
         while 1:
             canfit = None
             for fixedaddrinfo in canrelocate:
                 fitsection, inlist = fixedaddrinfo
                 fitsize, fitalign, fitname = fitsection
                 if addpos + fitsize > nextfixedaddr:
                     # Can't fit and nothing else will fit.
                     break
                 fitnextaddr = alignpos(addpos, fitalign) + fitsize
 #                print "Test %s - %x vs %x" % (
 #                    fitname, fitnextaddr, nextfixedaddr)
                 if fitnextaddr > nextfixedaddr:
                     # This item can't fit.
                     continue
                 canfit = (fitnextaddr, fixedaddrinfo)
             if canfit is None:
                 break
             # Found a section that can fit.
             fitnextaddr, fixedaddrinfo = canfit
             canrelocate.remove(fixedaddrinfo)
             fitsection, inlist = fixedaddrinfo
             inlist.remove(fitsection)
             extrasections.append(fitsection)
             addpos = fitnextaddr
             totalused += fitsection[0]
 #            print "    Adding %s (size %d align %d) pos=%x avail=%d" % (
 #                fitsection[2], fitsection[0], fitsection[1]
 #                , fitnextaddr, nextfixedaddr - fitnextaddr)
     firstfixed = fixedsections[0][0]

     # Report stats
     total = MAXPOS-firstfixed
     slack = total - totalused
     print ("Fixed space: 0x%x-0x%x  total: %d  slack: %d"
            "  Percent slack: %.1f%%" % (
             firstfixed, MAXPOS, total, slack,
             (float(slack) / total) * 100.0))

     # Find overall start position
     start16 = getSectionsStart(
         textsections + rodatasections + datasections, firstfixed)

     # Write header
     output = open(outname, 'wb')
     output.write(COMMONHEADER + """
         .text16 0x%x : {
                 code16_start = ABSOLUTE(.) ;
                 freespace_end = . ;
 """ % start16)

     # Write regular sections
     outSections(output, textsections)
     output.write("code16_rodata = . ;\n")
     outSections(output, rodatasections)
     outSections(output, datasections)

     # Write fixed sections
     for addr, section, extrasections in fixedsections:
         name = section[2]
         output.write(". = ( 0x%x - code16_start ) ;\n" % (addr,))
         output.write("*(%s)\n" % (name,))
         for extrasection in extrasections:
             output.write("*(%s)\n" % (extrasection[2],))

     # Write trailer
     output.write("""
                 code16_end = ABSOLUTE(.) ;
         }

         /* Discard regular data sections to force a link error if
          * 16bit code attempts to access data not marked with VAR16
          */
         /DISCARD/ : { *(.text*) *(.rodata*) *(.data*) *(.bss*) *(COMMON) }
 """ + COMMONTRAILER)

     return start16


 ######################################################################
 # 32bit section outputting
 ######################################################################

 # Return the subset of sections with a given name prefix
 def getSectionsPrefix(sections, prefix):
     lp = len(prefix)
     out = []
     for size, align, name in sections:
         if name[:lp] == prefix:
             out.append((size, align, name))
     return out

 # Layout the 32bit code.  This places the code as high as possible.
 def doLayout32(sections, outname, start16):
     start16 += 0xf0000
     # Find sections to output
     textsections = getSectionsPrefix(sections, '.text.')
     rodatasections = getSectionsPrefix(sections, '.rodata')
     datasections = getSectionsPrefix(sections, '.data.')
     bsssections = getSectionsPrefix(sections, '.bss.')
     start32 = getSectionsStart(
         textsections + rodatasections + datasections + bsssections, start16, 512)

     # Write sections
     output = open(outname, 'wb')
     output.write(COMMONHEADER + """
         .text32 0x%x : {
                 code32_start = ABSOLUTE(.) ;
 """ % start32)

     outSections(output, textsections)
     output.write("code32_rodata = . ;\n")
     outSections(output, rodatasections)
     outSections(output, datasections)
     outSections(output, bsssections)

     output.write("""
                 freespace_start = . ;
                 code32_end = ABSOLUTE(.) ;
         }
 """ + COMMONTRAILER)


 ######################################################################
 # Section garbage collection
 ######################################################################

 # Note required section, and recursively set all referenced sections
 # as required.
 def keepsection(name, pri, alt):
     if name in pri[3]:
         # Already kept - nothing to do.
         return
     pri[3].append(name)
     relocs = pri[2].get(name)
     if relocs is None:
         return
     # Keep all sections that this section points to
     for symbol in relocs:
         addr, section = pri[1].get(symbol, (None, None))
         if (section is not None and '*' not in section
             and section[:9] != '.discard.'):
             keepsection(section, pri, alt)
             continue
         # Not in primary sections - it may be a cross 16/32 reference
         addr, section = alt[1].get(symbol, (None, None))
         if section is not None and '*' not in section:
             keepsection(section, alt, pri)

 # Determine which sections are actually referenced and need to be
 # placed into the output file.
 def gc(info16, info32):
     # pri = (sections, symbols, relocs, keep sections)
     pri = (info16[0], info16[1], info16[2], [])
     alt = (info32[0], info32[1], info32[2], [])
     # Start by keeping sections that are globally visible.
     for size, align, section in info16[0]:
         if section[:11] == '.fixedaddr.' or '.export.' in section:
             keepsection(section, pri, alt)
     # Return sections found.
     sections16 = []
     for info in info16[0]:
         size, align, section = info
         if section not in pri[3]:
 #            print "gc16", section
             continue
         sections16.append(info)
     sections32 = []
     for info in info32[0]:
         size, align, section = info
         if section not in alt[3]:
 #            print "gc32", section
             continue
         sections32.append(info)
     return sections16, sections32


 ######################################################################
 # Startup and input parsing
 ######################################################################

 # Read in output from objdump
 def parseObjDump(file):
     # sections = [(size, align, section), ...]
     sections = []
     # symbols[symbol] = section
     symbols = {}
     # relocs[section] = [symbol, ...]
     relocs = {}

     state = None
     for line in file.readlines():
         line = line.rstrip()
         if line == 'Sections:':
             state = 'section'
             continue
         if line == 'SYMBOL TABLE:':
             state = 'symbol'
             continue
         if line[:24] == 'RELOCATION RECORDS FOR [':
             state = 'reloc'
             relocsection = line[24:-2]
             continue

         if state == 'section':
             try:
                 idx, name, size, vma, lma, fileoff, align = line.split()
                 if align[:3] != '2**':
                     continue
                 sections.append((int(size, 16), 2**int(align[3:]), name))
             except:
                 pass
             continue
         if state == 'symbol':
             try:
                 section, off, symbol = line[17:].split()
                 off = int(off, 16)
                 addr = int(line[:8], 16)
                 symbols[symbol] = addr, section
             except:
                 pass
             continue
         if state == 'reloc':
             try:
                 off, type, symbol = line.split()
                 off = int(off, 16)
                 relocs.setdefault(relocsection, []).append(symbol)
             except:
                 pass
     return sections, symbols, relocs

 def main():
     # Get output name
     in16, in32, out16, out32 = sys.argv[1:]

     infile16 = open(in16, 'rb')
     infile32 = open(in32, 'rb')

     info16 = parseObjDump(infile16)
     info32 = parseObjDump(infile32)

     sections16, sections32 = gc(info16, info32)

     start16 = doLayout16(sections16, out16)
     doLayout32(sections32, out32, start16)

 if __name__ == '__main__':
     main()
	#!/usr/bin/env python
	# Script to analyze code and arrange ld sections.
	#
	# Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
	#
	# This file may be distributed under the terms of the GNU GPLv3 license.

	import sys

	# Align 'pos' to 'alignbytes' offset
	def alignpos(pos, alignbytes):
	mask = alignbytes - 1
	return (pos + mask) & ~mask

	# LD script headers/trailers
	COMMONHEADER = """
	/* DO NOT EDIT! This is an autogenerated file. See tools/layoutrom.py. */
	OUTPUT_FORMAT("elf32-i386")
	OUTPUT_ARCH("i386")
	SECTIONS
	{
	"""
	COMMONTRAILER = """
	}
	"""


	######################################################################
	# 16bit fixed address section fitting
	######################################################################

	# Get the maximum start position for a list of sections that end at an
	# address.
	def getSectionsStart(sections, endaddr, minalign=1):
	totspace = 0
	for size, align, name in sections:
	if align > minalign:
	minalign = align
	totspace = alignpos(totspace, align) + size
	return (endaddr - totspace) / minalign * minalign

	# Write LD script includes for the given sections
	def outSections(file, sections):
	for size, align, name in sections:
	file.write("*(%s)\n" % (name,))

	# The 16bit code can't exceed 64K of space.
	MAXPOS = 64*1024

	# Layout the 16bit code. This ensures sections with fixed offset
	# requirements are placed in the correct location. It also places the
	# 16bit code as high as possible in the f-segment.
	def doLayout16(sections, outname):
	textsections = []
	rodatasections = []
	datasections = []
	# fixedsections = [(addr, sectioninfo, extasectionslist), ...]
	fixedsections = []
	# canrelocate = [(sectioninfo, list), ...]
	canrelocate = []

	# Find desired sections.
	for section in sections:
	size, align, name = section
	if name[:11] == '.fixedaddr.':
	addr = int(name[11:], 16)
	fixedsections.append((addr, section, []))
	if align != 1:
	print "Error: Fixed section %s has non-zero alignment (%d)" % (
	name, align)
	sys.exit(1)
	if name[:6] == '.text.':
	textsections.append(section)
	canrelocate.append((section, textsections))
	if name[:17] == '.rodata.__func__.' or name == '.rodata.str1.1':
	rodatasections.append(section)
	#canrelocate.append((section, rodatasections))
	if name[:8] == '.data16.':
	datasections.append(section)
	#canrelocate.append((section, datasections))

	# Find freespace in fixed address area
	fixedsections.sort()
	# fixedAddr = [(freespace, sectioninfo), ...]
	fixedAddr = []
	for i in range(len(fixedsections)):
	fixedsectioninfo = fixedsections[i]
	addr, section, extrasectionslist = fixedsectioninfo
	if i == len(fixedsections) - 1:
	nextaddr = MAXPOS
	else:
	nextaddr = fixedsections[i+1][0]
	avail = nextaddr - addr - section[0]
	fixedAddr.append((avail, fixedsectioninfo))

	# Attempt to fit other sections into fixed area
	fixedAddr.sort()
	canrelocate.sort()
	totalused = 0
	for freespace, fixedsectioninfo in fixedAddr:
	fixedaddr, fixedsection, extrasections = fixedsectioninfo
	addpos = fixedaddr + fixedsection[0]
	totalused += fixedsection[0]
	nextfixedaddr = addpos + freespace
	# print "Filling section %x uses %d, next=%x, available=%d" % (
	# fixedaddr, fixedsection[0], nextfixedaddr, freespace)
	while 1:
	canfit = None
	for fixedaddrinfo in canrelocate:
	fitsection, inlist = fixedaddrinfo
	fitsize, fitalign, fitname = fitsection
	if addpos + fitsize > nextfixedaddr:
	# Can't fit and nothing else will fit.
	break
	fitnextaddr = alignpos(addpos, fitalign) + fitsize
	# print "Test %s - %x vs %x" % (
	# fitname, fitnextaddr, nextfixedaddr)
	if fitnextaddr > nextfixedaddr:
	# This item can't fit.
	continue
	canfit = (fitnextaddr, fixedaddrinfo)
	if canfit is None:
	break
	# Found a section that can fit.
	fitnextaddr, fixedaddrinfo = canfit
	canrelocate.remove(fixedaddrinfo)
	fitsection, inlist = fixedaddrinfo
	inlist.remove(fitsection)
	extrasections.append(fitsection)
	addpos = fitnextaddr
	totalused += fitsection[0]
	# print " Adding %s (size %d align %d) pos=%x avail=%d" % (
	# fitsection[2], fitsection[0], fitsection[1]
	# , fitnextaddr, nextfixedaddr - fitnextaddr)
	firstfixed = fixedsections[0][0]

	# Report stats
	total = MAXPOS-firstfixed
	slack = total - totalused
	print ("Fixed space: 0x%x-0x%x total: %d slack: %d"
	" Percent slack: %.1f%%" % (
	firstfixed, MAXPOS, total, slack,
	(float(slack) / total) * 100.0))

	# Find overall start position
	start16 = getSectionsStart(
	textsections + rodatasections + datasections, firstfixed)

	# Write header
	output = open(outname, 'wb')
	output.write(COMMONHEADER + """
	.text16 0x%x : {
	code16_start = ABSOLUTE(.) ;
	freespace_end = . ;
	""" % start16)

	# Write regular sections
	outSections(output, textsections)
	output.write("code16_rodata = . ;\n")
	outSections(output, rodatasections)
	outSections(output, datasections)

	# Write fixed sections
	for addr, section, extrasections in fixedsections:
	name = section[2]
	output.write(". = ( 0x%x - code16_start ) ;\n" % (addr,))
	output.write("*(%s)\n" % (name,))
	for extrasection in extrasections:
	output.write("*(%s)\n" % (extrasection[2],))

	# Write trailer
	output.write("""
	code16_end = ABSOLUTE(.) ;
	}

	/* Discard regular data sections to force a link error if
	* 16bit code attempts to access data not marked with VAR16
	*/
	/DISCARD/ : { (.text) (.rodata) (.data) (.bss) *(COMMON) }
	""" + COMMONTRAILER)

	return start16


	######################################################################
	# 32bit section outputting
	######################################################################

	# Return the subset of sections with a given name prefix
	def getSectionsPrefix(sections, prefix):
	lp = len(prefix)
	out = []
	for size, align, name in sections:
	if name[:lp] == prefix:
	out.append((size, align, name))
	return out

	# Layout the 32bit code. This places the code as high as possible.
	def doLayout32(sections, outname, start16):
	start16 += 0xf0000
	# Find sections to output
	textsections = getSectionsPrefix(sections, '.text.')
	rodatasections = getSectionsPrefix(sections, '.rodata')
	datasections = getSectionsPrefix(sections, '.data.')
	bsssections = getSectionsPrefix(sections, '.bss.')
	start32 = getSectionsStart(
	textsections + rodatasections + datasections + bsssections, start16, 512)

	# Write sections
	output = open(outname, 'wb')
	output.write(COMMONHEADER + """
	.text32 0x%x : {
	code32_start = ABSOLUTE(.) ;
	""" % start32)

	outSections(output, textsections)
	output.write("code32_rodata = . ;\n")
	outSections(output, rodatasections)
	outSections(output, datasections)
	outSections(output, bsssections)

	output.write("""
	freespace_start = . ;
	code32_end = ABSOLUTE(.) ;
	}
	""" + COMMONTRAILER)


	######################################################################
	# Section garbage collection
	######################################################################

	# Note required section, and recursively set all referenced sections
	# as required.
	def keepsection(name, pri, alt):
	if name in pri[3]:
	# Already kept - nothing to do.
	return
	pri[3].append(name)
	relocs = pri[2].get(name)
	if relocs is None:
	return
	# Keep all sections that this section points to
	for symbol in relocs:
	addr, section = pri[1].get(symbol, (None, None))
	if (section is not None and '*' not in section
	and section[:9] != '.discard.'):
	keepsection(section, pri, alt)
	continue
	# Not in primary sections - it may be a cross 16/32 reference
	addr, section = alt[1].get(symbol, (None, None))
	if section is not None and '*' not in section:
	keepsection(section, alt, pri)

	# Determine which sections are actually referenced and need to be
	# placed into the output file.
	def gc(info16, info32):
	# pri = (sections, symbols, relocs, keep sections)
	pri = (info16[0], info16[1], info16[2], [])
	alt = (info32[0], info32[1], info32[2], [])
	# Start by keeping sections that are globally visible.
	for size, align, section in info16[0]:
	if section[:11] == '.fixedaddr.' or '.export.' in section:
	keepsection(section, pri, alt)
	# Return sections found.
	sections16 = []
	for info in info16[0]:
	size, align, section = info
	if section not in pri[3]:
	# print "gc16", section
	continue
	sections16.append(info)
	sections32 = []
	for info in info32[0]:
	size, align, section = info
	if section not in alt[3]:
	# print "gc32", section
	continue
	sections32.append(info)
	return sections16, sections32


	######################################################################
	# Startup and input parsing
	######################################################################

	# Read in output from objdump
	def parseObjDump(file):
	# sections = [(size, align, section), ...]
	sections = []
	# symbols[symbol] = section
	symbols = {}
	# relocs[section] = [symbol, ...]
	relocs = {}

	state = None
	for line in file.readlines():
	line = line.rstrip()
	if line == 'Sections:':
	state = 'section'
	continue
	if line == 'SYMBOL TABLE:':
	state = 'symbol'
	continue
	if line[:24] == 'RELOCATION RECORDS FOR [':
	state = 'reloc'
	relocsection = line[24:-2]
	continue

	if state == 'section':
	try:
	idx, name, size, vma, lma, fileoff, align = line.split()
	if align[:3] != '2**':
	continue
	sections.append((int(size, 16), 2**int(align[3:]), name))
	except:
	pass
	continue
	if state == 'symbol':
	try:
	section, off, symbol = line[17:].split()
	off = int(off, 16)
	addr = int(line[:8], 16)
	symbols[symbol] = addr, section
	except:
	pass
	continue
	if state == 'reloc':
	try:
	off, type, symbol = line.split()
	off = int(off, 16)
	relocs.setdefault(relocsection, []).append(symbol)
	except:
	pass
	return sections, symbols, relocs

	def main():
	# Get output name
	in16, in32, out16, out32 = sys.argv[1:]

	infile16 = open(in16, 'rb')
	infile32 = open(in32, 'rb')

	info16 = parseObjDump(infile16)
	info32 = parseObjDump(infile32)

	sections16, sections32 = gc(info16, info32)

	start16 = doLayout16(sections16, out16)
	doLayout32(sections32, out32, start16)

	if __name__ == '__main__':
	main()