#!perl -w
# (C) 2003-2007 Willem Jan Hengeveld <itsme@xs4all.nl>
# Web: http://www.xs4all.nl/~itsme/
#      http://wiki.xda-developers.com/
#
# $Id: $
#
# this script analyzes an IBMPC style partition table
#

#  todo: add option to specify a different sector size
#
use strict;
use IO::File;
use Getopt::Long;

my %typelist= (
    0x00=>'Empty',
    0x01=>'FAT-12',
    0x02=>'XENIX',
    0x03=>'XENIX',
    0x04=>'FAT-16',
    0x05=>'Extended Partition',
    0x06=>'DOS >32Meg',
    0x07=>'NTFS',
    0x0A=>'Boot Manager',
    0x0B=>'FAT-32',
    0x0e=>'WIN95: DOS 16-bit FAT, LBA',
    0x0f=>'WIN95: Extpartition, LBA',
    0x11=>'hid FAT-12',
    0x14=>'hid FAT-16',
    0x17=>'hid OS/2 HPFS',
    0x1B=>'hid FAT-32',
    0x1c=>'Hid WIN95 OSR2 FAT32, LBA',
    0x1e=>'hid WIN95: DOS 16-bit FAT, LBA',
    0x1f=>'hid WIN95: Ext partition, LBA',
    0x41=>'linux/minix',
    0x82=>'linux/swap',
    0x83=>'linux/native',
    0x64=>'Novell',
    0x75=>'PCIX',
    0xDB=>'CPM/Concurrent',
    0xFF=>'BBT',
);
sub usage {
    return <<__EOF__
Usage: dumpptable [-o OFFSET] [-b SECSIZE] <imagefile>
__EOF__
}

my $offset=0;
my $sectorsize=0x200;
GetOptions(
    "o=s" => sub { $offset=eval($_[1]); },
    "b=s" => sub { $sectorsize=eval($_[1]); },
) or die usage();

my $fn= shift or die "need filename\n";
my $fh= IO::File->new($fn, "r") or die "$fn: $!\n";
binmode $fh;

$fh->seek($offset, SEEK_SET);

my $data;
$fh->read($data, 512);
$fh->close();

if (substr($data, 510, 2) ne "\x55\xaa") {
    warn "missing 55aa signature at end of ptable\n";
}
for (0..3) {
    my $pdata= substr($data, 0x1be+0x10*$_, 0x10);
    next if ($pdata eq "\x00" x 16);
    my $ptab= parsepentry($pdata);
    printpentry($ptab);
}
sub printpentry {
    my $pent= shift;
    printf("%1s (%s) - (%s) %08lx %08lx %s\n",
        $pent->{bootable}?"B":"",
        chs_asstring($pent->{startchs}),
        chs_asstring($pent->{endchs}),
        $pent->{startsector},
        $pent->{nrsectors},
        type_asstring($pent->{type}));
    printf("offset: %08lx00 - %08lx00  l=%08lx00\n", 
        $offset/0x100+$pent->{startsector}*($sectorsize/0x100),
        $offset/0x100+$pent->{startsector}*($sectorsize/0x100)+ $pent->{nrsectors}*($sectorsize/0x100), $pent->{nrsectors}*($sectorsize/0x100));
}
sub chs_asstring {
    my $chs= shift;
    return sprintf("%03x:%02x:%02x", $chs->{cyl}, $chs->{side}, $chs->{sect});
}
sub type_asstring {
    my $type= shift;
    if (exists $typelist{$type}) {
        return $typelist{$type};
    }
    return sprintf("%02x", $type);
}
sub parsepentry {
    my $pdata= shift;
    my %pent;
    my ($startchs, $endchs);
    (
    $pent{bootable},
    $startchs,
    $pent{type},
    $endchs,
    $pent{startsector},
    $pent{nrsectors},
    ) = unpack("Ca3Ca3VV", $pdata);
    $pent{startchs}= parsechs($startchs);
    $pent{endchs}= parsechs($endchs);
    return \%pent;
}
sub parsechs {
    my @chsdata= unpack("C*", shift);
    return {
        side=>$chsdata[0],
        cyl=>(($chsdata[1]&0xc0)<<2) | $chsdata[2],
        sect=>$chsdata[1]&0x3f,
    };
}