mkdiskimage.in - pub/scm/boot/syslinux/syslinux - Git at Google

 #!/usr/bin/perl
 ## -----------------------------------------------------------------------
 ##
 ##   Copyright 2002-2008 H. Peter Anvin - All Rights Reserved
 ##
 ##   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 (sysopen($rfd, '/dev/urandom', O_RDONLY) &&
 	sysread($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;
 }

 $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";
     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 = '';
 while ( $line = <DATA> ) {
     chomp $line;
     foreach $byte ( split(/\s+/, $line) ) {
 	$mbr .= chr(hex($byte));
     }
 }
 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;

 $track = "\0" x (512*$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__
	#!/usr/bin/perl
	## -----------------------------------------------------------------------
	##
	## Copyright 2002-2008 H. Peter Anvin - All Rights Reserved
	##
	## 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 (sysopen($rfd, '/dev/urandom', O_RDONLY) &&
	sysread($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;
	}

	$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
	$c = ($c10242)/($h*$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";
	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 = $h$s512;

	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 = '';
	while ( $line = <DATA> ) {
	chomp $line;
	foreach $byte ( split(/\s+/, $line) ) {
	$mbr .= chr(hex($byte));
	}
	}
	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;

	$track = "\0" x (512*$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__