| #!/usr/bin/env python |
| # Work around x86emu bugs by replacing problematic instructions. |
| # |
| # Copyright (C) 2012 Kevin O'Connor <kevin@koconnor.net> |
| # |
| # This file may be distributed under the terms of the GNU GPLv3 license. |
| |
| # The x86emu code widely used in Linux distributions when running Xorg |
| # in vesamode is known to have issues with "retl", "leavel", "entryl", |
| # and some variants of "calll". This code modifies those instructions |
| # (ret and leave) that are known to be generated by gcc to avoid |
| # triggering the x86emu bugs. |
| |
| # It is also known that the Windows vgabios emulator has issues with |
| # addressing negative offsets to the %esp register. That has been |
| # worked around by not using the gcc parameter "-fomit-frame-pointer" |
| # when compiling. |
| |
| import sys |
| |
| def main(): |
| infilename, outfilename = sys.argv[1:] |
| infile = open(infilename, 'r') |
| out = [] |
| for line in infile: |
| sline = line.strip() |
| if sline == 'ret': |
| out.append('retw $2\n') |
| elif sline == 'leave': |
| out.append('movl %ebp, %esp ; popl %ebp\n') |
| elif sline.startswith('call'): |
| out.append('pushw %ax ; callw' + sline[4:] + '\n') |
| else: |
| out.append(line) |
| infile.close() |
| outfile = open(outfilename, 'w') |
| outfile.write(''.join(out)) |
| outfile.close() |
| |
| if __name__ == '__main__': |
| main() |
