mbr/checksize.pl

   1 ## -----------------------------------------------------------------------
   2 ##
   3 ##   Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
   4 ##   Copyright 2009 Intel Corporation; author: H. Peter Anvin
   5 ##
   6 ##   This program is free software; you can redistribute it and/or modify
   7 ##   it under the terms of the GNU General Public License as published by
   8 ##   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   9 ##   Boston MA 02111-1307, USA; either version 2 of the License, or
  10 ##   (at your option) any later version; incorporated herein by reference.
  11 ##
  12 ## -----------------------------------------------------------------------
  13
  14 ##
  15 ## checksize.pl
  16 ##
  17 ## Check the size of a binary file and pad it with zeroes to that size
  18 ##
  19
  20 use bytes;
  21
  22 ($file, $maxsize, $padsize) = @ARGV;
  23
  24 if (!defined($maxsize)) {
  25     # Defaults based on the filename
  26     if ($file =~ /^mbr[^0-9a-z]/) {
  27         $maxsize = $padsize = 440;
  28     } elsif ($file =~ /^gptmbr[^0-9a-z]/) {
  29         $maxsize = $padsize = 440;
  30     } elsif ($file =~ /^isohdp[fp]x[^0-9a-z]/) {
  31         $maxsize = $padsize = 432;
  32     } elsif ($file =~ /^altmbr[^0-9a-z]/) {
  33         $maxsize = $padsize = 439;
  34     } else {
  35         die "$0: no default size for filename: $file\n";
  36     }
  37 }
  38
  39 $padsize = $maxsize unless(defined($padsize));
  40
  41 open(FILE, '+<', $file) or die;
  42 @st = stat(FILE);
  43 if (!defined($size = $st[7])) {
  44     die "$0: $file: $!\n";
  45 }
  46 if ($size > $maxsize) {
  47     print STDERR "$file: too big ($size > $maxsize)\n";
  48     exit 1;
  49 } elsif ($size < $padsize) {
  50     seek(FILE, $size, 0);
  51     print FILE "\0" x ($padsize-$size);
  52 }
  53
  54 exit 0;