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author | Andreas Loibl <andreas@andreas-loibl.de> | 2012-03-02 23:09:10 +0100 |
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committer | Andreas Loibl <andreas@andreas-loibl.de> | 2012-03-02 23:09:10 +0100 |
commit | 6c3be6a60f6c7fee77c94f55b16f4d1f0f4a8df0 (patch) | |
tree | ff0b0c95d3988be528b9583659116fc755e43358 /isohybrid-bg2 | |
parent | abdc52c7c08ed0477b65d42f3d296a674943059a (diff) | |
download | kanotix-6c3be6a60f6c7fee77c94f55b16f4d1f0f4a8df0.zip kanotix-6c3be6a60f6c7fee77c94f55b16f4d1f0f4a8df0.tar.gz |
updated README, moved isohybrid-bg2 out of chroot
Diffstat (limited to 'isohybrid-bg2')
-rwxr-xr-x | isohybrid-bg2 | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/isohybrid-bg2 b/isohybrid-bg2 new file mode 100755 index 0000000..79eb28c --- /dev/null +++ b/isohybrid-bg2 @@ -0,0 +1,164 @@ +#!/usr/bin/perl +# Post-process an ISO 9660 image generated with mkisofs/genisoimage +# to allow "hybrid booting" as a CD-ROM or as a hard disk. +# +# This is isohybrid-bg2 - written by Andreas Loibl <andreas@andreas-loibl.de> +# +# It works for ISO images with BURG or GRUB2. For ISO images with +# syslinux/isolinux use isohybrid (written by H. Peter Anvin) +# +# isohybrid-bg2 is based on isohybrid: +## ----------------------------------------------------------------------- +## +## 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. +## +## ----------------------------------------------------------------------- + +# 512byte boot.img +$mbr='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'; + +($file) = @ARGV; +open(FILE, "+< $file\0") or die "$0: cannot open $file: $!\n"; +binmode FILE; + +# search pattern to find location of boot.isohybrid on ISO image +$pattern="ACRITOX!"x64; +$p=0; +while($p++ < 0xffff) +{ + seek(FILE, $p*512, SEEK_SET) or die "$0: $file: $!\n"; + read(FILE, $sector, 512) == 512 or die "$0: $file: read error\n"; + if($sector eq $pattern) + { + seek(FILE, 0, SEEK_SET) or die "$0: $file: $!\n"; + print FILE pack('H*',$mbr); + $boot_offset = hex(substr($mbr,2,2)); + seek(FILE, $boot_offset - 0x7, SEEK_SET) or die "$0: $file: $!\n"; + print FILE pack("V", $p+1); + seek(FILE, $p*512 + 0x3f4, SEEK_SET) or die "$0: $file: $!\n"; + print FILE pack("V", $p+2); + last; + } +} +if($p>0xffff) { + die "$0: error: $file does not contain boot.isohybrid in its first 32MB!\n"; +} + +# Use this fake geometry (zipdrive-style...) +$h = 64; $s = 32; + +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; +} + +# +# 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"; +} +# 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 +$cylsize = $h*$s*512; +$frac = $imgsize % $cylsize; +$padding = ($frac > 0) ? $cylsize - $frac : 0; +$imgsize += $padding; +$c = $imgsize/$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 = $c; +} + + +$mbr = pack("VV", $de_lba*4, 0); +if (defined($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 partition table +$psize = $c*$h*$s; +$bhead = 0; +$bsect = 1; +$bcyl = 0; +$ehead = $h-1; +$esect = $s + ((($cc-1) & 0x300) >> 2); +$ecyl = ($cc-1) & 0xff; +$fstype = 0x83; # Linux (any better ideas?) +$pentry = 1; # First partition slot + +for ( $i = 1 ; $i <= 4 ; $i++ ) { + if ( $i == $pentry ) { + $mbr .= pack("CCCCCCCCVV", 0x80, $bhead, $bsect, $bcyl, $fstype, + $ehead, $esect, $ecyl, 0, $psize); + } else { + $mbr .= "\0" x 16; + } +} +$mbr .= "\x55\xaa"; + +# Print the partition table +seek(FILE, 432, SEEK_SET) or die "$0: $file: $!\n"; +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; |