blob: 07ba71253dc7b4b8d8e23105cdb9af430e3b9aba [file] [log] [blame]
#!/usr/bin/perl
## -----------------------------------------------------------------------
##
## Copyright 2002-2008 H. Peter Anvin - All Rights Reserved
## Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, Inc., 53 Temple Place Ste 330,
## Boston MA 02111-1307, USA; either version 2 of the License, or
## (at your option) any later version; incorporated herein by reference.
##
## -----------------------------------------------------------------------
#
# Creates a blank MS-DOS formatted hard disk image
#
use bytes;
use integer;
use Fcntl;
use Errno;
use Cwd;
use IO::Handle; # For flush()
sub absolute_path($) {
my($f) = @_;
my($c);
return $f if ( $f =~ /^\// );
$c = cwd();
$c = '' if ( $c eq '/' );
return $c.'/'.$f;
}
sub is_linux() {
return !!eval '{ '.
'use POSIX; '.
'($sysname, $nodename, $release, $version, $machine) = POSIX::uname(); '.
"return \$sysname eq \'Linux\'; }";
}
sub get_random() {
# Get a 32-bit random number
my $rfd, $rnd;
my $rid;
if (open($rfd, "< /dev/urandom\0") && read($rfd, $rnd, 4) == 4) {
$rid = unpack("V", $rnd);
}
close($rfd) if (defined($rfd));
return $rid if (defined($rid));
# This sucks but is better than nothing...
return ($$+time()) & 0xffffffff;
}
sub get_hex_data() {
my $mbr = '';
my $line, $byte;
while ( $line = <DATA> ) {
chomp $line;
last if ($line eq '*');
foreach $byte ( split(/\s+/, $line) ) {
$mbr .= chr(hex($byte));
}
}
return $mbr;
}
$is_linux = is_linux();
if ( $is_linux ) {
# IOCTL numbers
$BLKRRPART = 0x125f;
$BLKGETSIZE = 0x1260;
}
%opt = ();
@args = ();
while (defined($a = shift(@ARGV))) {
if ( $a =~ /^\-/ ) {
foreach $o ( split(//, substr($a,1)) ) {
$opt{$o} = 1;
if ($o eq 'i') {
$id = shift(@ARGV);
}
}
} else {
push(@args, $a);
}
}
($file,$c,$h,$s) = @args;
$c += 0; $h += 0; $s += 0;
$pentry = 1;
$pentry = 2 if ( $opt{'2'} );
$pentry = 3 if ( $opt{'3'} );
$pentry = 4 if ( $opt{'4'} );
if ( $opt{'z'} ) {
$h = $h || 64;
$s = $s || 32;
}
if ( $opt{'M'} && $h && $s ) {
# Specify size in megabytes, not in cylinders
$c = ($c*1024*2)/($h*$s);
}
$is_open = 0;
if ( $c == 0 && $file ne '' ) {
$len = 0;
if ( sysopen(OUTPUT, $file, O_RDWR, 0666) ) {
$is_open = 1;
if ( (@filestat = stat(OUTPUT)) && S_ISREG($filestat[2]) ) {
$len = $filestat[7] >> 9;
} elsif ( $is_linux && S_ISBLK($filestat[2]) ) {
$blksize = pack("L!", 0);
if ( ioctl(OUTPUT, $BLKGETSIZE, $blksize) == 0 ) {
$len = unpack("L!", $blksize); # In 512-byte sectors!
}
}
}
if ( !$len ) {
print STDERR "$0: $file: don't know how to determine the size of this device\n";
exit 1;
}
$c = $len/($h*$s);
}
if ( $file eq '' || $c < 1 || $h < 1 || $h > 256 || $s < 1 || $s > 63 ) {
print STDERR "Usage: $0 [-doFMz4][-i id] file c h s (max: 1024 256 63)\n";
print STDERR " -d add DOSEMU header\n";
print STDERR " -o print filesystem offset to stdout\n";
print STDERR " -F format partition as FAT32\n";
print STDERR " -M \"c\" argument is megabytes, calculate cylinders\n";
print STDERR " -z use zipdisk geometry (h=64 s=32)\n";
print STDERR " -4 use partition entry 4 (standard for zipdisks)\n";
print STDERR " -i specify the MBR ID\n";
print STDERR " -s output a sparse file (don't allocate all blocks)\n";
exit 1;
}
if ($c > 1024) {
print STDERR "Warning: more than 1024 cylinders ($c).\n";
print STDERR "Not all BIOSes will be able to boot this device.\n";
$cc = 1024;
} else {
$cc = $c;
}
$cylsize = $h*$s*512;
if ( !$is_open ) {
sysopen(OUTPUT, $file, O_CREAT|O_RDWR|O_TRUNC, 0666)
or die "$0: Cannot open: $file\n";
}
binmode OUTPUT;
# Print out DOSEMU header, if requested
if ( $opt{'d'} ) {
$emuhdr = "DOSEMU\0" . pack("VVVV", $h, $s, $c, 128);
$emuhdr .= "\0" x (128 - length($emuhdr));
print OUTPUT $emuhdr;
}
# Print the MBR and partition table
$mbr = get_hex_data();
if ( length($mbr) > 440 ) {
die "$0: Bad MBR code\n";
}
$mbr .= "\0" x (440 - length($mbr));
if (defined($id)) {
$id = to_int($id);
} else {
$id = get_random();
}
$mbr .= pack("V", $id); # Offset 440: MBR ID
$mbr .= "\0\0"; # Offset 446: actual partition table
print OUTPUT $mbr;
# Print partition table
$psize = $c*$h*$s-$s;
$bhead = ($h > 1) ? 1 : 0;
$bsect = 1;
$bcyl = ($h > 1) ? 0 : 1;
$ehead = $h-1;
$esect = $s + ((($cc-1) & 0x300) >> 2);
$ecyl = ($cc-1) & 0xff;
if ( $c > 1024 ) {
$fstype = 0x0e;
} elsif ( $psize > 65536 ) {
$fstype = 0x06;
} else {
$fstype = 0x04;
}
for ( $i = 1 ; $i <= 4 ; $i++ ) {
if ( $i == $pentry ) {
print OUTPUT pack("CCCCCCCCVV", 0x80, $bhead, $bsect, $bcyl, $fstype,
$ehead, $esect, $ecyl, $s, $psize);
} else {
print OUTPUT "\0" x 16;
}
}
print OUTPUT "\x55\xaa";
# Output blank file
$totalsize = $c*$h*$s;
$tracks = $c*$h;
# If -s is given, try to simply use truncate...
unless ($opt{'s'} && truncate(OUTPUT, $totalsize)) {
$track = "\0" x (512*$s);
# Print fractional track
print OUTPUT "\0" x (512 * ($s-1));
for ( $i = 1 ; $i < $tracks ; $i++ ) {
print OUTPUT $track;
}
}
# Print mtools temp file
$n = 0;
while ( !defined($tmpdir) ) {
$tmpdir = "/tmp/mkdiskimage.$$.".($n++);
if ( !mkdir($tmpdir, 0700) ) {
die "$0: Failed to make temp directory: $tmpdir\n"
if ( $! != EEXIST );
undef $tmpdir;
}
}
$cfgfile = $tmpdir.'/mtools.conf';
$imglink = $tmpdir.'/disk.img';
die "$0: Failed to create symlink $imglink\n"
if ( !symlink(absolute_path($file), $imglink) );
$header_size = ($opt{'d'} ? 128 : 0);
# Start of filesystem
$offset = $s*512 + $header_size;
# Start of partition table entry
$pstart = $header_size + 446 + 16*($pentry-1);
open(MCONFIG, "> ${cfgfile}") or die "$0: Cannot make mtools config\n";
print MCONFIG "drive z:\n";
print MCONFIG "file=\"${imglink}\"\n";
print MCONFIG "cylinders=${c}\n";
print MCONFIG "heads=${h}\n";
print MCONFIG "sectors=${s}\n";
print MCONFIG "offset=${offset}\n";
print MCONFIG "mformat_only\n";
close(MCONFIG);
# Output the filesystem offset to stdout if appropriate
if ( $opt{'o'} ) {
print $offset, "\n";
}
$ENV{'MTOOLSRC'} = $cfgfile;
if ( $opt{'F'} ) {
system('mformat', '-F', 'z:');
} else {
system('mformat', 'z:');
}
# Clean up in /tmp
unlink($cfgfile);
unlink($imglink);
rmdir($tmpdir);
# MTOOLS doesn't write the bsHiddenSecs field correctly
seek(OUTPUT, $offset + 0x1c, 0);
print OUTPUT pack("V", ($offset-$header_size)>>9);
# Set the partition type
if ( $opt{'F'} ) {
if ( $c > 1024 ) {
$fstype = 0x0c; # FAT32 LBA
} else {
$fstype = 0x0b;
}
} else {
if ( $c > 1024 ) {
$fstype = 0x0e; # FAT16 LBA
} elsif ( $psize > 65536 ) {
$fstype = 0x06; # FAT16 > 32MB
} else {
$fstype = 0x04; # FAT16 <= 32MB
}
seek(OUTPUT, $offset + 0x36, 0);
read(OUTPUT, $fsname, 8);
# FAT12: adjust partition type
if ( $fsname eq 'FAT12 ' ) {
$fstype = 0x01; # FAT12
}
}
seek(OUTPUT, $pstart+4, 0);
print OUTPUT pack("C", $fstype);
flush OUTPUT;
# Just in case this is a block device, try to flush the partition table
if ( $is_linux ) {
ioctl(OUTPUT, $BLKRRPART, 0);
};
exit 0;
__END__
33 c0 fa 8e d8 8e d0 bc 0 7c 89 e6 6 57 8e c0 fb fc bf 0 6 b9 0 1 f3 a5 ea
1f 6 0 0 52 52 b4 41 bb aa 55 31 c9 30 f6 f9 cd 13 72 13 81 fb 55 aa 75 d
d1 e9 73 9 66 c7 6 8d 6 b4 42 eb 15 5a b4 8 cd 13 83 e1 3f 51 f b6 c6 40 f7
e1 52 50 66 31 c0 66 99 e8 66 0 e8 35 1 4d 69 73 73 69 6e 67 20 6f 70 65 72
61 74 69 6e 67 20 73 79 73 74 65 6d 2e d a 66 60 66 31 d2 bb 0 7c 66 52 66
50 6 53 6a 1 6a 10 89 e6 66 f7 36 f4 7b c0 e4 6 88 e1 88 c5 92 f6 36 f8 7b
88 c6 8 e1 41 b8 1 2 8a 16 fa 7b cd 13 8d 64 10 66 61 c3 e8 c4 ff be be 7d
bf be 7 b9 20 0 f3 a5 c3 66 60 89 e5 bb be 7 b9 4 0 31 c0 53 51 f6 7 80 74
3 40 89 de 83 c3 10 e2 f3 48 74 5b 79 39 59 5b 8a 47 4 3c f 74 6 24 7f 3c
5 75 22 66 8b 47 8 66 8b 56 14 66 1 d0 66 21 d2 75 3 66 89 c2 e8 ac ff 72
3 e8 b6 ff 66 8b 46 1c e8 a0 ff 83 c3 10 e2 cc 66 61 c3 e8 76 0 4d 75 6c 74
69 70 6c 65 20 61 63 74 69 76 65 20 70 61 72 74 69 74 69 6f 6e 73 2e d a 66
8b 44 8 66 3 46 1c 66 89 44 8 e8 30 ff 72 27 66 81 3e 0 7c 58 46 53 42 75
9 66 83 c0 4 e8 1c ff 72 13 81 3e fe 7d 55 aa f 85 f2 fe bc fa 7b 5a 5f 7
fa ff e4 e8 1e 0 4f 70 65 72 61 74 69 6e 67 20 73 79 73 74 65 6d 20 6c 6f
61 64 20 65 72 72 6f 72 2e d a 5e ac b4 e 8a 3e 62 4 b3 7 cd 10 3c a 75 f1
cd 18 f4 eb fd 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
*