/* gpt.c - Read GUID Partition Tables (GPT). */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2005,2006,2007,2008 Free Software Foundation, Inc.
*
* GRUB 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, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see .
*/
#include
#include
#include
#include
#include
#include
#include
static grub_uint8_t grub_gpt_magic[8] =
{
0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54
};
static const grub_gpt_part_type_t grub_gpt_partition_type_empty = GRUB_GPT_PARTITION_TYPE_EMPTY;
/* 512 << 7 = 65536 byte sectors. */
#define MAX_SECTOR_LOG 7
static struct grub_partition_map grub_gpt_partition_map;
static grub_err_t
gpt_partition_map_iterate (grub_disk_t disk,
int (*hook) (grub_disk_t disk,
const grub_partition_t partition))
{
struct grub_partition part;
struct grub_gpt_header gpt;
struct grub_gpt_partentry entry;
struct grub_msdos_partition_mbr mbr;
grub_uint64_t entries;
unsigned int i;
int last_offset = 0;
int sector_log = 0;
/* Read the protective MBR. */
if (grub_disk_read (disk, 0, 0, sizeof (mbr), &mbr))
return grub_errno;
/* Check if it is valid. */
if (mbr.signature != grub_cpu_to_le16 (GRUB_PC_PARTITION_SIGNATURE))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
/* Make sure the MBR is a protective MBR and not a normal MBR. */
if (mbr.entries[0].type != GRUB_PC_PARTITION_TYPE_GPT_DISK)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "no GPT partition map found");
/* Read the GPT header. */
for (sector_log = 0; sector_log < MAX_SECTOR_LOG; sector_log++)
{
if (grub_disk_read (disk, 1 << sector_log, 0, sizeof (gpt), &gpt))
return grub_errno;
if (grub_memcmp (gpt.magic, grub_gpt_magic, sizeof (grub_gpt_magic)) == 0)
break;
}
if (sector_log == MAX_SECTOR_LOG)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "no valid GPT header");
grub_dprintf ("gpt", "Read a valid GPT header\n");
entries = grub_le_to_cpu64 (gpt.partitions) << sector_log;
for (i = 0; i < grub_le_to_cpu32 (gpt.maxpart); i++)
{
if (grub_disk_read (disk, entries, last_offset,
sizeof (entry), &entry))
return grub_errno;
if (grub_memcmp (&grub_gpt_partition_type_empty, &entry.type,
sizeof (grub_gpt_partition_type_empty)))
{
/* Calculate the first block and the size of the partition. */
part.start = grub_le_to_cpu64 (entry.start) << sector_log;
part.len = (grub_le_to_cpu64 (entry.end)
- grub_le_to_cpu64 (entry.start) + 1) << sector_log;
part.offset = entries;
part.number = i;
part.index = last_offset;
part.partmap = &grub_gpt_partition_map;
grub_dprintf ("gpt", "GPT entry %d: start=%lld, length=%lld\n", i,
(unsigned long long) part.start,
(unsigned long long) part.len);
if (hook (disk, &part))
return grub_errno;
}
last_offset += grub_le_to_cpu32 (gpt.partentry_size);
if (last_offset == GRUB_DISK_SECTOR_SIZE)
{
last_offset = 0;
entries++;
}
}
return GRUB_ERR_NONE;
}
/* Partition map type. */
static struct grub_partition_map grub_gpt_partition_map =
{
.name = "gpt",
.iterate = gpt_partition_map_iterate,
};
GRUB_MOD_INIT(part_gpt)
{
grub_partition_map_register (&grub_gpt_partition_map);
}
GRUB_MOD_FINI(part_gpt)
{
grub_partition_map_unregister (&grub_gpt_partition_map);
}