| #!/usr/bin/env python |
| # Script to arrange sections to ensure fixed offsets. |
| # |
| # Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net> |
| # |
| # This file may be distributed under the terms of the GNU GPLv3 license. |
| |
| import sys |
| |
| |
| def alignpos(pos, alignbytes): |
| mask = alignbytes - 1 |
| return (pos + mask) & ~mask |
| |
| |
| ###################################################################### |
| # 16bit fixed address section fitting |
| ###################################################################### |
| |
| MAXPOS = 0x10000 |
| |
| 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] |
| |
| # Find overall start position |
| restalign = 0 |
| restspace = 0 |
| restsections = [] |
| for section in textsections + rodatasections + datasections: |
| size, align, name = section |
| if align > restalign: |
| restalign = align |
| restspace = alignpos(restspace, align) + size |
| restsections.append(section) |
| startrest = (firstfixed - restspace) / restalign * restalign |
| |
| # 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)) |
| |
| # Write header |
| output = open(outname, 'wb') |
| output.write(""" |
| .text16 0x%x : { |
| code16_start = ABSOLUTE(.) ; |
| freespace_end = . ; |
| """ % startrest) |
| |
| # Write regular sections |
| for section in restsections: |
| name = section[2] |
| if name == rodatasections[0][2]: |
| output.write("code16_rodata = . ;\n") |
| output.write("*(%s)\n" % (name,)) |
| |
| # 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(.) ; |
| } |
| """) |
| |
| |
| ###################################################################### |
| # 32bit section outputting |
| ###################################################################### |
| |
| def outsections(file, sections, prefix): |
| lp = len(prefix) |
| for size, align, name in sections: |
| if name[:lp] == prefix: |
| file.write("*(%s)\n" % (name,)) |
| |
| def doLayout32(sections, outname): |
| output = open(outname, 'wb') |
| outsections(output, sections, '.text.') |
| output.write("code32_rodata = . ;\n") |
| outsections(output, sections, '.rodata') |
| outsections(output, sections, '.data.') |
| outsections(output, sections, '.bss.') |
| |
| |
| ###################################################################### |
| # Section garbage collection |
| ###################################################################### |
| |
| 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: |
| section = pri[1].get(symbol) |
| if section is not None and section[:9] != '.discard.': |
| keepsection(section, pri, alt) |
| continue |
| # Not in primary sections - it may be a cross 16/32 reference |
| section = alt[1].get(symbol) |
| if section is not None: |
| keepsection(section, alt, pri) |
| |
| 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) |
| if '*' not in section: |
| symbols[symbol] = 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) |
| |
| doLayout16(sections16, out16) |
| doLayout32(sections32, out32) |
| |
| if __name__ == '__main__': |
| main() |