read part of GPT partition table working

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;