isolinux: protect bss variables clobbered due to final sector load
[syslinux.git] / lstadjust.pl
blobe2e395fed6de00f29b6c45f8f5b3a182b102e272
1 #!/usr/bin/perl
3 # Take a NASM list and map file and make the offsets in the list file
4 # absolute. This makes debugging a lot easier.
6 # Usage:
8 # lstadjust.pl listfile mapfile outfile
11 ($listfile, $mapfile, $outfile) = @ARGV;
13 open(LST, "< $listfile\0")
14 or die "$0: cannot open: $listfile: $!\n";
15 open(MAP, "< $mapfile\0")
16 or die "$0: cannot open: $mapfile: $!\n";
17 open(OUT, "> $outfile\0")
18 or die "$0: cannot create: $outfile: $!\n";
20 %vstart = ();
21 undef $sec;
23 while (defined($line = <MAP>)) {
24 chomp $line;
25 if ($line =~ /^\-+\s+Section\s+(\S+)\s+\-/) {
26 $sec = $1;
28 next unless (defined($sec));
29 if ($line =~ /^vstart:\s+([0-9a-f]+)/i) {
30 $vstart{$sec} = hex $1;
33 close(MAP);
35 $offset = 0;
36 @ostack = ();
38 while (defined($line = <LST>)) {
39 chomp $line;
41 $source = substr($line, 40);
42 if ($source =~ /^([^;]*);/) {
43 $source = $1;
46 ($label, $op, $arg, $tail) = split(/\s+/, $source);
47 if ($op =~ /^(|\[)section$/i) {
48 $offset = $vstart{$arg};
49 } elsif ($op =~ /^(absolute|\[absolute)$/i) {
50 $offset = 0;
51 } elsif ($op =~ /^struc$/i) {
52 push(@ostack, $offset);
53 $offset = 0;
54 } elsif ($op =~ /^endstruc$/i) {
55 $offset = pop(@ostack);
58 if ($line =~ /^(\s*[0-9]+ )([0-9A-F]{8})(\s.*)$/) {
59 $line = sprintf("%s%08X%s", $1, (hex $2)+$offset, $3);
62 print OUT $line, "\n";