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Diffstat (limited to 'contrib/syslinux-4.02/utils/isohybrid.in')
| -rw-r--r-- | contrib/syslinux-4.02/utils/isohybrid.in | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/utils/isohybrid.in b/contrib/syslinux-4.02/utils/isohybrid.in new file mode 100644 index 0000000..a127784 --- /dev/null +++ b/contrib/syslinux-4.02/utils/isohybrid.in @@ -0,0 +1,258 @@ +#!/usr/bin/perl +## ----------------------------------------------------------------------- +## +## Copyright 2002-2008 H. Peter Anvin - All Rights Reserved +## Copyright 2009 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. +## +## ----------------------------------------------------------------------- + +# +# Post-process an ISO 9660 image generated with mkisofs/genisoimage +# to allow "hybrid booting" as a CD-ROM or as a hard disk. +# + +use bytes; +use Fcntl; + +# User-specifyable options +%opt = ( + # Fake geometry (zipdrive-style...) + 'h' => 64, + 's' => 32, + # Partition number + 'entry' => 1, + # Partition offset + 'offset' => 0, + # Partition type + 'type' => 0x17, # "Windows hidden IFS" + # MBR ID + 'id' => undef, +); + +%valid_range = ( + 'h' => [1, 256], + 's' => [1, 63], + 'entry' => [1, 4], + 'offset' => [0, 64], + 'type' => [0, 255], + 'id' => [0, 0xffffffff], + 'hd0' => [0, 2], + 'partok' => [0, 1], +); + +# Boolean options just set other options +%bool_opt = ( + 'nohd0' => ['hd0', 0], + 'forcehd0' => ['hd0', 1], + 'ctrlhd0' => ['hd0', 2], + 'nopartok' => ['partok', 0], + 'partok' => ['partok', 1], +); + +sub usage() { + print STDERR "Usage: $0 [options] filename.iso\n", + "Options:\n", + " -h Number of default geometry heads\n", + " -s Number of default geometry sectors\n", + " -entry Specify partition entry number (1-4)\n", + " -offset Specify partition offset (default 0)\n", + " -type Specify partition type (default 0x17)\n", + " -id Specify MBR ID (default random)\n", + " -forcehd0 Always assume we are loaded as disk ID 0\n", + " -ctrlhd0 Assume disk ID 0 if the Ctrl key is pressed\n", + " -partok Allow booting from within a partition\n"; + exit 1; +} + +# Parse a C-style integer (decimal/octal/hex) +sub doh($) { + my($n) = @_; + return ($n =~ /^0/) ? oct $n : $n+0; +} + +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 $mbr; +} + +while ($ARGV[0] =~ /^\-(.*)$/) { + $o = $1; + shift @ARGV; + if (defined($bool_opt{$o})) { + ($o, $v) = @{$bool_opt{$o}}; + $opt{$o} = $v; + } elsif (exists($opt{$o})) { + $opt{$o} = doh(shift @ARGV); + if (defined($valid_range{$o})) { + ($l, $h) = @{$valid_range{$o}}; + if ($opt{$o} < $l || $opt{$o} > $h) { + die "$0: valid values for the -$o parameter are $l to $h\n"; + } + } + } else { + usage(); + } +} + +($file) = @ARGV; + +if (!defined($file)) { + usage(); +} + +open(FILE, "+< $file\0") or die "$0: cannot open $file: $!\n"; +binmode FILE; + +# +# First, actually figure out where mkisofs hid isolinux.bin +# +seek(FILE, 17*2048, SEEK_SET) or die "$0: $file: $!\n"; +read(FILE, $boot_record, 2048) == 2048 or die "$0: $file: read error\n"; +($br_sign, $br_cat_offset) = unpack("a71V", $boot_record); +if ($br_sign ne ("\0CD001\1EL TORITO SPECIFICATION" . ("\0" x 41))) { + die "$0: $file: no boot record found\n"; +} +seek(FILE, $br_cat_offset*2048, SEEK_SET) or die "$0: $file: $!\n"; +read(FILE, $boot_cat, 2048) == 2048 or die "$0: $file: read error\n"; + +# We must have a Validation Entry followed by a Default Entry... +# no fanciness allowed for the Hybrid mode [XXX: might relax this later] +@ve = unpack("v16", $boot_cat); +$cs = 0; +for ($i = 0; $i < 16; $i++) { + $cs += $ve[$i]; +} +if ($ve[0] != 0x0001 || $ve[15] != 0xaa55 || $cs & 0xffff) { + die "$0: $file: invalid boot catalog\n"; +} +($de_boot, $de_media, $de_seg, $de_sys, $de_mbz1, $de_count, + $de_lba, $de_mbz2) = unpack("CCvCCvVv", substr($boot_cat, 32, 32)); +if ($de_boot != 0x88 || $de_media != 0 || + ($de_segment != 0 && $de_segment != 0x7c0) || $de_count != 4) { + die "$0: $file: unexpected boot catalog parameters\n"; +} + +# Now $de_lba should contain the CD sector number for isolinux.bin +seek(FILE, $de_lba*2048+0x40, SEEK_SET) or die "$0: $file: $!\n"; +read(FILE, $ibsig, 4); +if ($ibsig ne "\xfb\xc0\x78\x70") { + die "$0: $file: bootloader does not have a isolinux.bin hybrid signature.". + "Note that isolinux-debug.bin does not support hybrid booting.\n"; +} + +# Get the total size of the image +(@imgstat = stat(FILE)) or die "$0: $file: $!\n"; +$imgsize = $imgstat[7]; +if (!$imgsize) { + die "$0: $file: cannot determine length of file\n"; +} +# Target image size: round up to a multiple of $h*$s*512 +$h = $opt{'h'}; +$s = $opt{'s'}; +$cylsize = $h*$s*512; +$frac = $imgsize % $cylsize; +$padding = ($frac > 0) ? $cylsize - $frac : 0; +$imgsize += $padding; +$c = int($imgsize/$cylsize); +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 = $c; +} + +# Preserve id when run again +if (defined($opt{'id'})) { + $id = pack("V", doh($opt{'id'})); +} else { + seek(FILE, 440, SEEK_SET) or die "$0: $file: $!\n"; + read(FILE, $id, 4); + if ($id eq "\x00\x00\x00\x00") { + $id = pack("V", get_random()); + } +} + +# Print the MBR and partition table +seek(FILE, 0, SEEK_SET) or die "$0: $file: $!\n"; + +for ($i = 0; $i <= $opt{'hd0'}+3*$opt{'partok'}; $i++) { + $mbr = get_hex_data(); +} +if ( length($mbr) > 432 ) { + die "$0: Bad MBR code\n"; +} + +$mbr .= "\0" x (432 - length($mbr)); + +$mbr .= pack("VV", $de_lba*4, 0); # Offset 432: LBA of isolinux.bin +$mbr .= $id; # Offset 440: MBR ID +$mbr .= "\0\0"; # Offset 446: actual partition table + +# Print partition table +$offset = $opt{'offset'}; +$psize = $c*$h*$s - $offset; +$bhead = int($offset/$s) % $h; +$bsect = ($offset % $s) + 1; +$bcyl = int($offset/($h*$s)); +$bsect += ($bcyl & 0x300) >> 2; +$bcyl &= 0xff; +$ehead = $h-1; +$esect = $s + ((($cc-1) & 0x300) >> 2); +$ecyl = ($cc-1) & 0xff; +$fstype = $opt{'type'}; # Partition type +$pentry = $opt{'entry'}; # Partition slot + +for ( $i = 1 ; $i <= 4 ; $i++ ) { + if ( $i == $pentry ) { + $mbr .= pack("CCCCCCCCVV", 0x80, $bhead, $bsect, $bcyl, $fstype, + $ehead, $esect, $ecyl, $offset, $psize); + } else { + $mbr .= "\0" x 16; + } +} +$mbr .= "\x55\xaa"; + +print FILE $mbr; + +# Pad the image to a fake cylinder boundary +seek(FILE, $imgstat[7], SEEK_SET) or die "$0: $file: $!\n"; +if ($padding) { + print FILE "\0" x $padding; +} + +# Done... +close(FILE); + +exit 0; +__END__ |