cs.pl

   1 #!/usr/bin/perl
   2 #
   3 # cs.pl --
   4 #
   5 #      Calculate sectors and save to loaderSectors
   6
   7 use strict;
   8 use warnings;
   9
  10 my $off = 0;
  11
  12 my $map = "link.map";
  13 open MAP, "<$map" or die "Unable to open $map: $!";
  14 while (my $line = <MAP>) {
  15    if ($line =~ m/(0x[0-9a-f]+)\s+loaderSectors/) {
  16       $off = hex($1) - 0x7c00;
  17       last;
  18    }
  19 }
  20
  21 my $bytes = (stat('boot'))[7];
  22 my $sectors = int(($bytes + 512) / 512) - 1;
  23
  24 my $image = "boot.img";
  25
  26 open IMG, "+<$image" or die "Unable to open $image: $!";
  27 binmode IMG;
  28 seek IMG, $off, 0;
  29
  30 my $n = syswrite IMG, pack('S', $sectors), 2;
  31
  32 close IMG;
  33
  34 print sprintf("  ==> Writing 0x%04x to loaderSectors at offset 0x%x\n",
  35               $sectors, $off);