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Diffstat (limited to 'perl-install/partition_table_gpt.pm')
| -rw-r--r-- | perl-install/partition_table_gpt.pm | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/perl-install/partition_table_gpt.pm b/perl-install/partition_table_gpt.pm new file mode 100644 index 000000000..d908a8103 --- /dev/null +++ b/perl-install/partition_table_gpt.pm @@ -0,0 +1,174 @@ +package partition_table_gpt; # $Id$ + +use diagnostics; +use strict; +use vars qw(@ISA); + +@ISA = qw(partition_table_raw); + +use common; +use partition_table_raw; +use partition_table_dos; +use partition_table; +use c; + +my %gpt_types = ( + 0x00 => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", + 0x82 => "\x6d\xfd\x57\x06\xab\xa4\xc4\x43\x84\xe5\x09\x33\xc8\x4b\x4f\x4f", + 0x83 => "\xA2\xA0\xD0\xEB\xE5\xB9\x33\x44\x87\xC0\x68\xB6\xB7\x26\x99\xC7", + 0x8e => "\x79\xd3\xd6\xe6\x07\xf5\xc2\x44\xa2\x3c\x23\x8f\x2a\x3d\xf9\x28", + 0xfd => "\x0f\x88\x9d\xa1\xfc\x05\x3b\x4d\xa0\x06\x74\x3f\x0f\x84\x91\x1e", + 0xef => "\x28\x73\x2A\xC1\x1F\xF8\xd2\x11\xBA\x4B\x00\xA0\xC9\x3E\xC9\x3B", + # legacy_partition_table => "\x41\xEE\x4D\x02\xE7\x33\xd3\x11\x9D\x69\x00\x08\xC7\x81\xF3\x9F" + # PARTITION_MSFT_RESERVED_GUID "\x16\xE3\xC9\xE3\x5C\x0B\xB8\x4D\x81\x7D\xF9\x2D\xF0\x02\x15\xAE" + #PARTITION_RESERVED_GUID "\x39\x33\xa6\x8d\x07\x00\xc0\x60\xc4\x36\x08\x3a\xc8\x23\x09\x08" +); + +my $current_revision = 0x00010200; +my ($main_format, $main_fields) = list2kv( + a8 => 'magic', + V => 'revision', + V => 'headerSize', + V => 'headerCRC32', + a4 => 'blank1', + Q => 'myLBA', + Q => 'alternateLBA', + Q => 'firstUsableLBA', + Q => 'lastUsableLBA', + a16 => 'guid', + Q => 'partitionEntriesLBA', + V => 'nbPartitions', + V => 'partitionEntrySize', + V => 'partitionEntriesCRC32', +); + +my ($partitionEntry_format, $partitionEntry_fields) = list2kv( + a16 => 'gpt_type', + a16 => 'guid', + Q => 'start', + Q => 'ending', + a8 => 'efi_attributes', + a72 => 'name', +); + +$_ = join('', @$_) foreach $main_format, $partitionEntry_format; + +my $magic = "EFI PART"; + +sub crc32 { + my ($buffer) = @_; + + my $crc = 0xFFFFFFFF; + foreach (unpack "C*", $buffer) { + my $subcrc = ($crc ^ $_) & 0xFF; + for (my $j = 8; $j > 0; $j--){ + my $b = $subcrc & 1; + $subcrc = ($subcrc >> 1) & 0x7FFFFFFF; + $subcrc = $subcrc ^ 0xEDB88320 if $b; + } + $crc = ($crc >> 8) ^ $subcrc; + } + $crc; +} + +sub compute_crc { + my ($info) = @_; + local $info->{headerCRC32} = 0; + my $tmp = pack($main_format, @$info{@$main_fields}); + crc32($tmp) ^ 0xFFFFFFFF; +} + +sub read { + my ($hd, $sector) = @_; + my $tmp; + + my $l = partition_table_dos::read($hd, $sector); + my @l = grep { $_->{size} && $_->{type} && !partition_table::isExtended($_) } @$l; + @l == 1 or die "bad PMBR"; + $l[0]{type} == 0xee or die "bad PMBR"; + my $myLBA = $l[0]{start}; + + local *F; partition_table_raw::openit($hd, *F) or die "failed to open device"; + c::lseek_sector(fileno(F), $myLBA, 0) or die "reading of partition in sector $sector failed"; + + sysread F, $tmp, psizeof($main_format) or die "error while reading partition table in sector $sector"; + my %info; @info{@$main_fields} = unpack $main_format, $tmp; + + $info{magic} eq $magic or die "bad magic number"; + $info{myLBA} == $myLBA or die "myLBA is not the same"; + $info{headerSize} == psizeof($main_format) or die "bad partition table header size"; + $info{partitionEntrySize} == psizeof($partitionEntry_format) or die "bad partitionEntrySize"; + $info{revision} <= $current_revision or log::l("oops, this is a new GPT revision ($info{revision} > $current_revision)"); + + my $chksum = compute_crc(\%info); + $chksum == $info{headerCRC32} or die "bad checksum"; + + c::lseek_sector(fileno(F), $info{partitionEntriesLBA}, 0) or die "can't seek to sector partitionEntriesLBA"; + my %gpt_types_rev = reverse %gpt_types; + my @pt = map { + sysread F, $tmp, psizeof($partitionEntry_format) or die "error while reading partition table in sector $sector"; + my %h; @h{@$partitionEntry_fields} = unpack $partitionEntry_format, $tmp; + $h{size} = $h{ending} - $h{start}; + $h{type} = $gpt_types_rev{$h{gpt_type}}; + $h{type} = 0x100 if !defined $h{type}; + \%h; + } (1 .. $info{nbPartitions}); + + [ @pt ], \%info; +} + +# write the partition table (and extended ones) +# for each entry, it uses fields: start, size, type, active +sub write { + my ($hd, undef, $pt, $info) = @_; + + local *F; + partition_table_raw::openit($hd, *F, 2) or die "error opening device $hd->{device} for writing"; + + foreach (@$pt) { + $_->{ending} = $_->{start} + $_->{size}; + $_->{gpt_type} = $gpt_types{$_->{type}} || $gpt_types{0x83}; + } + + $info->{csum} = compute_crc($info); + + c::lseek_sector(fileno(F), $info->{myLBA}, 0) or return 0; + #- pad with 0's + syswrite F, pack($main_format, @$info{@$main_fields}) . "\0" x 512, 512 or return 0; + + c::lseek_sector(fileno(F), $info->{myLBA}, 0) or return 0; + + + common::sync(); + 1; +} + +sub info { + my ($hd) = @_; + + #- build a default suitable partition table, + #- checksum will be built when writing on disk. + my $info = { + magic => $magic, + revision => $current_revision + }; + + $info; +} + +sub clear_raw { + my ($hd) = @_; + my $pt = { raw => [ ({}) x 128 ], info => info($hd) }; + + #- handle special case for partition 2 which is whole disk. + $pt->{raw}[2] = { + type => 5, #- the whole disk type. + flags => 0, + start_cylinder => 0, + size => $hd->{geom}{cylinders} * $hd->cylinder_size(), + }; + + $pt; +} + +1; |