diff options
Diffstat (limited to 'qemu/roms/seabios/scripts/layoutrom.py')
| -rwxr-xr-x | qemu/roms/seabios/scripts/layoutrom.py | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/qemu/roms/seabios/scripts/layoutrom.py b/qemu/roms/seabios/scripts/layoutrom.py new file mode 100755 index 000000000..dd770fe49 --- /dev/null +++ b/qemu/roms/seabios/scripts/layoutrom.py @@ -0,0 +1,691 @@ +#!/usr/bin/env python +# Script to analyze code and arrange ld sections. +# +# Copyright (C) 2008-2014 Kevin O'Connor <kevin@koconnor.net> +# +# This file may be distributed under the terms of the GNU GPLv3 license. + +import operator +import sys + +# LD script headers/trailers +COMMONHEADER = """ +/* DO NOT EDIT! This is an autogenerated file. See scripts/layoutrom.py. */ +OUTPUT_FORMAT("elf32-i386") +OUTPUT_ARCH("i386") +SECTIONS +{ +""" +COMMONTRAILER = """ + + /* Discard regular data sections to force a link error if + * code attempts to access data not marked with VAR16 (or other + * appropriate macro) + */ + /DISCARD/ : { + *(.text*) *(.data*) *(.bss*) *(.rodata*) + *(COMMON) *(.discard*) *(.eh_frame) *(.note*) + } +} +""" + + +###################################################################### +# Determine section locations +###################################################################### + +# Align 'pos' to 'alignbytes' offset +def alignpos(pos, alignbytes): + mask = alignbytes - 1 + return (pos + mask) & ~mask + +# Determine the final addresses for a list of sections that end at an +# address. +def setSectionsStart(sections, endaddr, minalign=1, segoffset=0): + totspace = 0 + for section in sections: + if section.align > minalign: + minalign = section.align + totspace = alignpos(totspace, section.align) + section.size + startaddr = int((endaddr - totspace) / minalign) * minalign + curaddr = startaddr + for section in sections: + curaddr = alignpos(curaddr, section.align) + section.finalloc = curaddr + section.finalsegloc = curaddr - segoffset + curaddr += section.size + return startaddr, minalign + +# The 16bit code can't exceed 64K of space. +BUILD_BIOS_ADDR = 0xf0000 +BUILD_BIOS_SIZE = 0x10000 +BUILD_ROM_START = 0xc0000 +BUILD_LOWRAM_END = 0xa0000 +# Space to reserve in f-segment for dynamic allocations +BUILD_MIN_BIOSTABLE = 2048 + +# 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 fitSections(sections, fillsections): + # fixedsections = [(addr, section), ...] + fixedsections = [] + for section in sections: + if section.name.startswith('.fixedaddr.'): + addr = int(section.name[11:], 16) + section.finalloc = addr + BUILD_BIOS_ADDR + section.finalsegloc = addr + fixedsections.append((addr, section)) + if section.align != 1: + print("Error: Fixed section %s has non-zero alignment (%d)" % ( + section.name, section.align)) + sys.exit(1) + fixedsections.sort(key=operator.itemgetter(0)) + firstfixed = fixedsections[0][0] + + # Find freespace in fixed address area + # fixedAddr = [(freespace, section), ...] + fixedAddr = [] + for i in range(len(fixedsections)): + fixedsectioninfo = fixedsections[i] + addr, section = fixedsectioninfo + if i == len(fixedsections) - 1: + nextaddr = BUILD_BIOS_SIZE + else: + nextaddr = fixedsections[i+1][0] + avail = nextaddr - addr - section.size + fixedAddr.append((avail, section)) + fixedAddr.sort(key=operator.itemgetter(0)) + + # Attempt to fit other sections into fixed area + canrelocate = [(section.size, section.align, section.name, section) + for section in fillsections] + canrelocate.sort() + canrelocate = [section for size, align, name, section in canrelocate] + totalused = 0 + for freespace, fixedsection in fixedAddr: + addpos = fixedsection.finalsegloc + fixedsection.size + totalused += fixedsection.size + nextfixedaddr = addpos + freespace +# print("Filling section %x uses %d, next=%x, available=%d" % ( +# fixedsection.finalloc, fixedsection.size, nextfixedaddr, freespace)) + while 1: + canfit = None + for fitsection in canrelocate: + if addpos + fitsection.size > nextfixedaddr: + # Can't fit and nothing else will fit. + break + fitnextaddr = alignpos(addpos, fitsection.align) + fitsection.size +# print("Test %s - %x vs %x" % ( +# fitsection.name, fitnextaddr, nextfixedaddr)) + if fitnextaddr > nextfixedaddr: + # This item can't fit. + continue + canfit = (fitnextaddr, fitsection) + if canfit is None: + break + # Found a section that can fit. + fitnextaddr, fitsection = canfit + canrelocate.remove(fitsection) + fitsection.finalloc = addpos + BUILD_BIOS_ADDR + fitsection.finalsegloc = addpos + addpos = fitnextaddr + totalused += fitsection.size +# print(" Adding %s (size %d align %d) pos=%x avail=%d" % ( +# fitsection[2], fitsection[0], fitsection[1] +# , fitnextaddr, nextfixedaddr - fitnextaddr)) + + # Report stats + total = BUILD_BIOS_SIZE-firstfixed + slack = total - totalused + print ("Fixed space: 0x%x-0x%x total: %d slack: %d" + " Percent slack: %.1f%%" % ( + firstfixed, BUILD_BIOS_SIZE, total, slack, + (float(slack) / total) * 100.0)) + + return firstfixed + BUILD_BIOS_ADDR + +# Return the subset of sections with a given category +def getSectionsCategory(sections, category): + return [section for section in sections if section.category == category] + +# Return the subset of sections with a given fileid +def getSectionsFileid(sections, fileid): + return [section for section in sections if section.fileid == fileid] + +# Return the subset of sections with a given name prefix +def getSectionsPrefix(sections, prefix): + return [section for section in sections + if section.name.startswith(prefix)] + +# The sections (and associated information) to be placed in output rom +class LayoutInfo: + sections = None + genreloc = None + sec32init_start = sec32init_end = sec32init_align = None + sec32low_start = sec32low_end = None + zonelow_base = final_sec32low_start = None + zonefseg_start = zonefseg_end = None + final_readonly_start = None + varlowsyms = entrysym = None + +# Determine final memory addresses for sections +def doLayout(sections, config, genreloc): + li = LayoutInfo() + li.sections = sections + li.genreloc = genreloc + # Determine 16bit positions + sections16 = getSectionsCategory(sections, '16') + textsections = getSectionsPrefix(sections16, '.text.') + rodatasections = getSectionsPrefix(sections16, '.rodata') + datasections = getSectionsPrefix(sections16, '.data16.') + fixedsections = getSectionsCategory(sections, 'fixed') + + firstfixed = fitSections(fixedsections, textsections) + remsections = [s for s in textsections+rodatasections+datasections + if s.finalloc is None] + sec16_start, sec16_align = setSectionsStart( + remsections, firstfixed, segoffset=BUILD_BIOS_ADDR) + + # Determine 32seg positions + sections32seg = getSectionsCategory(sections, '32seg') + textsections = getSectionsPrefix(sections32seg, '.text.') + rodatasections = getSectionsPrefix(sections32seg, '.rodata') + datasections = getSectionsPrefix(sections32seg, '.data32seg.') + + sec32seg_start, sec32seg_align = setSectionsStart( + textsections + rodatasections + datasections, sec16_start + , segoffset=BUILD_BIOS_ADDR) + + # Determine 32bit "fseg memory" data positions + sections32textfseg = getSectionsCategory(sections, '32textfseg') + sec32textfseg_start, sec32textfseg_align = setSectionsStart( + sections32textfseg, sec32seg_start, 16) + + sections32fseg = getSectionsCategory(sections, '32fseg') + sec32fseg_start, sec32fseg_align = setSectionsStart( + sections32fseg, sec32textfseg_start, 16 + , segoffset=BUILD_BIOS_ADDR) + + # Determine 32flat runtime positions + sections32flat = getSectionsCategory(sections, '32flat') + textsections = getSectionsPrefix(sections32flat, '.text.') + rodatasections = getSectionsPrefix(sections32flat, '.rodata') + datasections = getSectionsPrefix(sections32flat, '.data.') + bsssections = getSectionsPrefix(sections32flat, '.bss.') + + sec32flat_start, sec32flat_align = setSectionsStart( + textsections + rodatasections + datasections + bsssections + , sec32fseg_start, 16) + + # Determine 32flat init positions + sections32init = getSectionsCategory(sections, '32init') + init32_textsections = getSectionsPrefix(sections32init, '.text.') + init32_rodatasections = getSectionsPrefix(sections32init, '.rodata') + init32_datasections = getSectionsPrefix(sections32init, '.data.') + init32_bsssections = getSectionsPrefix(sections32init, '.bss.') + + sec32init_start, sec32init_align = setSectionsStart( + init32_textsections + init32_rodatasections + + init32_datasections + init32_bsssections + , sec32flat_start, 16) + + # Determine location of ZoneFSeg memory. + zonefseg_end = sec32flat_start + if not genreloc: + zonefseg_end = sec32init_start + zonefseg_start = BUILD_BIOS_ADDR + if zonefseg_start + BUILD_MIN_BIOSTABLE > zonefseg_end: + # Not enough ZoneFSeg space - force a minimum space. + zonefseg_end = sec32fseg_start + zonefseg_start = zonefseg_end - BUILD_MIN_BIOSTABLE + sec32flat_start, sec32flat_align = setSectionsStart( + textsections + rodatasections + datasections + bsssections + , zonefseg_start, 16) + sec32init_start, sec32init_align = setSectionsStart( + init32_textsections + init32_rodatasections + + init32_datasections + init32_bsssections + , sec32flat_start, 16) + li.sec32init_start = sec32init_start + li.sec32init_end = sec32flat_start + li.sec32init_align = sec32init_align + final_readonly_start = min(BUILD_BIOS_ADDR, sec32flat_start) + if not genreloc: + final_readonly_start = min(BUILD_BIOS_ADDR, sec32init_start) + li.zonefseg_start = zonefseg_start + li.zonefseg_end = zonefseg_end + li.final_readonly_start = final_readonly_start + + # Determine "low memory" data positions + sections32low = getSectionsCategory(sections, '32low') + sec32low_end = sec32init_start + if config.get('CONFIG_MALLOC_UPPERMEMORY'): + final_sec32low_end = final_readonly_start + zonelow_base = final_sec32low_end - 64*1024 + zonelow_base = max(BUILD_ROM_START, alignpos(zonelow_base, 2*1024)) + else: + final_sec32low_end = BUILD_LOWRAM_END + zonelow_base = final_sec32low_end - 64*1024 + relocdelta = final_sec32low_end - sec32low_end + li.sec32low_start, li.sec32low_align = setSectionsStart( + sections32low, sec32low_end, 16 + , segoffset=zonelow_base - relocdelta) + li.sec32low_end = sec32low_end + li.zonelow_base = zonelow_base + li.final_sec32low_start = li.sec32low_start + relocdelta + + # Print statistics + size16 = BUILD_BIOS_ADDR + BUILD_BIOS_SIZE - sec16_start + size32seg = sec16_start - sec32seg_start + size32textfseg = sec32seg_start - sec32textfseg_start + size32fseg = sec32textfseg_start - sec32fseg_start + size32flat = sec32fseg_start - sec32flat_start + size32init = sec32flat_start - sec32init_start + sizelow = li.sec32low_end - li.sec32low_start + print("16bit size: %d" % size16) + print("32bit segmented size: %d" % size32seg) + print("32bit flat size: %d" % (size32flat + size32textfseg)) + print("32bit flat init size: %d" % size32init) + print("Lowmem size: %d" % sizelow) + print("f-segment var size: %d" % size32fseg) + return li + + +###################################################################### +# Linker script output +###################################################################### + +# Write LD script includes for the given cross references +def outXRefs(sections, useseg=0, exportsyms=[], forcedelta=0): + xrefs = dict([(symbol.name, symbol) for symbol in exportsyms]) + out = "" + for section in sections: + for reloc in section.relocs: + symbol = reloc.symbol + if (symbol.section is not None + and (symbol.section.fileid != section.fileid + or symbol.name != reloc.symbolname)): + xrefs[reloc.symbolname] = symbol + for symbolname, symbol in xrefs.items(): + loc = symbol.section.finalloc + if useseg: + loc = symbol.section.finalsegloc + out += "%s = 0x%x ;\n" % (symbolname, loc + forcedelta + symbol.offset) + return out + +# Write LD script includes for the given sections +def outSections(sections, useseg=0): + out = "" + for section in sections: + loc = section.finalloc + if useseg: + loc = section.finalsegloc + out += "%s 0x%x : { *(%s) }\n" % (section.name, loc, section.name) + return out + +# Write LD script includes for the given sections using relative offsets +def outRelSections(sections, startsym, useseg=0): + sections = [(section.finalloc, section) for section in sections + if section.finalloc is not None] + sections.sort(key=operator.itemgetter(0)) + out = "" + for addr, section in sections: + loc = section.finalloc + if useseg: + loc = section.finalsegloc + out += ". = ( 0x%x - %s ) ;\n" % (loc, startsym) + if section.name in ('.rodata.str1.1', '.rodata'): + out += "_rodata%s = . ;\n" % (section.fileid,) + out += "*%s.*(%s)\n" % (section.fileid, section.name) + return out + +# Build linker script output for a list of relocations. +def strRelocs(outname, outrel, relocs): + relocs.sort() + return (" %s_start = ABSOLUTE(.) ;\n" % (outname,) + + "".join(["LONG(0x%x - %s)\n" % (pos, outrel) + for pos in relocs]) + + " %s_end = ABSOLUTE(.) ;\n" % (outname,)) + +# Find relocations to the given sections +def getRelocs(sections, tosection, type=None): + return [section.finalloc + reloc.offset + for section in sections + for reloc in section.relocs + if (reloc.symbol.section in tosection + and (type is None or reloc.type == type))] + +# Output the linker scripts for all required sections. +def writeLinkerScripts(li, out16, out32seg, out32flat): + # Write 16bit linker script + filesections16 = getSectionsFileid(li.sections, '16') + out = outXRefs(filesections16, useseg=1) + """ + zonelow_base = 0x%x ; + _zonelow_seg = 0x%x ; + +%s +""" % (li.zonelow_base, + int(li.zonelow_base / 16), + outSections(filesections16, useseg=1)) + outfile = open(out16, 'w') + outfile.write(COMMONHEADER + out + COMMONTRAILER) + outfile.close() + + # Write 32seg linker script + filesections32seg = getSectionsFileid(li.sections, '32seg') + out = (outXRefs(filesections32seg, useseg=1) + + outSections(filesections32seg, useseg=1)) + outfile = open(out32seg, 'w') + outfile.write(COMMONHEADER + out + COMMONTRAILER) + outfile.close() + + # Write 32flat linker script + sec32all_start = li.sec32low_start + relocstr = "" + if li.genreloc: + # Generate relocations + initsections = dict([ + (s, 1) for s in getSectionsCategory(li.sections, '32init')]) + noninitsections = dict([(s, 1) for s in li.sections + if s not in initsections]) + absrelocs = getRelocs(initsections, initsections, type='R_386_32') + relrelocs = getRelocs(initsections, noninitsections, type='R_386_PC32') + initrelocs = getRelocs(noninitsections, initsections) + relocstr = (strRelocs("_reloc_abs", "code32init_start", absrelocs) + + strRelocs("_reloc_rel", "code32init_start", relrelocs) + + strRelocs("_reloc_init", "code32flat_start", initrelocs)) + numrelocs = len(absrelocs + relrelocs + initrelocs) + sec32all_start -= numrelocs * 4 + filesections32flat = getSectionsFileid(li.sections, '32flat') + out = outXRefs([], exportsyms=li.varlowsyms + , forcedelta=li.final_sec32low_start-li.sec32low_start) + out += outXRefs(filesections32flat, exportsyms=[li.entrysym]) + """ + _reloc_min_align = 0x%x ; + zonefseg_start = 0x%x ; + zonefseg_end = 0x%x ; + zonelow_base = 0x%x ; + final_varlow_start = 0x%x ; + final_readonly_start = 0x%x ; + varlow_start = 0x%x ; + varlow_end = 0x%x ; + code32init_start = 0x%x ; + code32init_end = 0x%x ; + + code32flat_start = 0x%x ; + .text code32flat_start : { +%s +%s + code32flat_end = ABSOLUTE(.) ; + } :text +""" % (li.sec32init_align, + li.zonefseg_start, + li.zonefseg_end, + li.zonelow_base, + li.final_sec32low_start, + li.final_readonly_start, + li.sec32low_start, + li.sec32low_end, + li.sec32init_start, + li.sec32init_end, + sec32all_start, + relocstr, + outRelSections(li.sections, 'code32flat_start')) + out = COMMONHEADER + out + COMMONTRAILER + """ +ENTRY(%s) +PHDRS +{ + text PT_LOAD AT ( code32flat_start ) ; +} +""" % (li.entrysym.name,) + outfile = open(out32flat, 'w') + outfile.write(out) + outfile.close() + + +###################################################################### +# Detection of unused sections and init sections +###################################################################### + +# Visit all sections reachable from a given set of start sections +def findReachable(anchorsections, checkreloc, data): + anchorsections = dict([(section, []) for section in anchorsections]) + pending = list(anchorsections) + while pending: + section = pending.pop() + for reloc in section.relocs: + chain = anchorsections[section] + [section.name] + if not checkreloc(reloc, section, data, chain): + continue + nextsection = reloc.symbol.section + if nextsection not in anchorsections: + anchorsections[nextsection] = chain + pending.append(nextsection) + return anchorsections + +# Find "runtime" sections (ie, not init only sections). +def checkRuntime(reloc, rsection, data, chain): + section = reloc.symbol.section + if section is None or '.init.' in section.name: + return 0 + if '.data.varinit.' in section.name: + print("ERROR: %s is VARVERIFY32INIT but used from %s" % ( + section.name, chain)) + sys.exit(1) + return 1 + +# Find and keep the section associated with a symbol (if available). +def checkKeepSym(reloc, syms, fileid, isxref): + symbolname = reloc.symbolname + mustbecfunc = symbolname.startswith('_cfunc') + if mustbecfunc: + symprefix = '_cfunc' + fileid + '_' + if not symbolname.startswith(symprefix): + return 0 + symbolname = symbolname[len(symprefix):] + symbol = syms.get(symbolname) + if (symbol is None or symbol.section is None + or symbol.section.name.startswith('.discard.')): + return 0 + isdestcfunc = (symbol.section.name.startswith('.text.') + and not symbol.section.name.startswith('.text.asm.')) + if ((mustbecfunc and not isdestcfunc) + or (not mustbecfunc and isdestcfunc and isxref)): + return 0 + + reloc.symbol = symbol + return 1 + +# Resolve a relocation and check if it should be kept in the final binary. +def checkKeep(reloc, section, symbols, chain): + ret = checkKeepSym(reloc, symbols[section.fileid], section.fileid, 0) + if ret: + return ret + # Not in primary sections - it may be a cross 16/32 reference + for fileid in ('16', '32seg', '32flat'): + if fileid != section.fileid: + ret = checkKeepSym(reloc, symbols[fileid], fileid, 1) + if ret: + return ret + return 0 + + +###################################################################### +# Startup and input parsing +###################################################################### + +class Section: + name = size = alignment = fileid = relocs = None + finalloc = finalsegloc = category = None +class Reloc: + offset = type = symbolname = symbol = None +class Symbol: + name = offset = section = None + +# Read in output from objdump +def parseObjDump(file, fileid): + # sections = [section, ...] + sections = [] + sectionmap = {} + # symbols[symbolname] = symbol + symbols = {} + + 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.startswith('RELOCATION RECORDS FOR ['): + sectionname = line[24:-2] + if sectionname.startswith('.debug_'): + # Skip debugging sections (to reduce parsing time) + state = None + continue + state = 'reloc' + relocsection = sectionmap[sectionname] + continue + + if state == 'section': + try: + idx, name, size, vma, lma, fileoff, align = line.split() + if align[:3] != '2**': + continue + section = Section() + section.name = name + section.size = int(size, 16) + section.align = 2**int(align[3:]) + section.fileid = fileid + section.relocs = [] + sections.append(section) + sectionmap[name] = section + except ValueError: + pass + continue + if state == 'symbol': + try: + parts = line[17:].split() + if len(parts) == 3: + sectionname, size, name = parts + elif len(parts) == 4 and parts[2] == '.hidden': + sectionname, size, hidden, name = parts + else: + continue + symbol = Symbol() + symbol.size = int(size, 16) + symbol.offset = int(line[:8], 16) + symbol.name = name + symbol.section = sectionmap.get(sectionname) + symbols[name] = symbol + except ValueError: + pass + continue + if state == 'reloc': + try: + off, type, symbolname = line.split() + reloc = Reloc() + reloc.offset = int(off, 16) + reloc.type = type + reloc.symbolname = symbolname + reloc.symbol = symbols.get(symbolname) + if reloc.symbol is None: + # Some binutils (2.20.1) give section name instead + # of a symbol - create a dummy symbol. + reloc.symbol = symbol = Symbol() + symbol.size = 0 + symbol.offset = 0 + symbol.name = symbolname + symbol.section = sectionmap.get(symbolname) + symbols[symbolname] = symbol + relocsection.relocs.append(reloc) + except ValueError: + pass + return sections, symbols + +# Parser for constants in simple C header files. +def scanconfig(file): + f = open(file, 'r') + opts = {} + for l in f.readlines(): + parts = l.split() + if len(parts) != 3: + continue + if parts[0] != '#define': + continue + value = parts[2] + if value.isdigit() or (value.startswith('0x') and value[2:].isdigit()): + value = int(value, 0) + opts[parts[1]] = value + return opts + +def main(): + # Get output name + in16, in32seg, in32flat, cfgfile, out16, out32seg, out32flat = sys.argv[1:] + + # Read in the objdump information + infile16 = open(in16, 'r') + infile32seg = open(in32seg, 'r') + infile32flat = open(in32flat, 'r') + + # infoX = (sections, symbols) + info16 = parseObjDump(infile16, '16') + info32seg = parseObjDump(infile32seg, '32seg') + info32flat = parseObjDump(infile32flat, '32flat') + + # Read kconfig config file + config = scanconfig(cfgfile) + + # Figure out which sections to keep. + allsections = info16[0] + info32seg[0] + info32flat[0] + symbols = {'16': info16[1], '32seg': info32seg[1], '32flat': info32flat[1]} + if config.get('CONFIG_COREBOOT'): + entrysym = symbols['16'].get('entry_elf') + elif config.get('CONFIG_CSM'): + entrysym = symbols['16'].get('entry_csm') + else: + entrysym = symbols['16'].get('reset_vector') + anchorsections = [entrysym.section] + [ + section for section in allsections + if section.name.startswith('.fixedaddr.')] + keepsections = findReachable(anchorsections, checkKeep, symbols) + sections = [section for section in allsections if section in keepsections] + + # Separate 32bit flat into runtime, init, and special variable parts + anchorsections = [ + section for section in sections + if ('.data.varlow.' in section.name or '.data.varfseg.' in section.name + or '.fixedaddr.' in section.name or '.runtime.' in section.name)] + runtimesections = findReachable(anchorsections, checkRuntime, None) + for section in sections: + if section.name.startswith('.data.varlow.'): + section.category = '32low' + elif section.name.startswith('.data.varfseg.'): + section.category = '32fseg' + elif section.name.startswith('.text.32fseg.'): + section.category = '32textfseg' + elif section.name.startswith('.fixedaddr.'): + section.category = 'fixed' + elif section.fileid == '32flat' and section not in runtimesections: + section.category = '32init' + else: + section.category = section.fileid + + # Determine the final memory locations of each kept section. + genreloc = '_reloc_abs_start' in symbols['32flat'] + li = doLayout(sections, config, genreloc) + + # Exported symbols + li.varlowsyms = [symbol for symbol in symbols['32flat'].values() + if (symbol.section is not None + and symbol.section.finalloc is not None + and '.data.varlow.' in symbol.section.name + and symbol.name != symbol.section.name)] + li.entrysym = entrysym + + # Write out linker script files. + writeLinkerScripts(li, out16, out32seg, out32flat) + +if __name__ == '__main__': + main() |