grub/grub-core/partmap/gpt.c
Nicholas Vinson e6cc6f328a disk: Update grub_gpt_partentry
Rename grub_gpt_part_type to grub_gpt_part_guid and update grub_gpt_partentry
to use this type for both the partition type GUID string and the partition GUID
string entries.  This change ensures that the two GUID fields are handled more
consistently and helps to simplify the changes needed to add Linux partition
GUID support.

Signed-off-by: Nicholas Vinson <nvinson234@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-09-21 13:19:10 -04:00

231 lines
6.3 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* 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 <http://www.gnu.org/licenses/>.
*/
#include <grub/disk.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/partition.h>
#include <grub/dl.h>
#include <grub/msdos_partition.h>
#include <grub/gpt_partition.h>
#include <grub/i18n.h>
GRUB_MOD_LICENSE ("GPLv3+");
static grub_uint8_t grub_gpt_magic[8] =
{
0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54
};
static const grub_gpt_part_guid_t grub_gpt_partition_type_empty = GRUB_GPT_PARTITION_TYPE_EMPTY;
#ifdef GRUB_UTIL
static const grub_gpt_part_guid_t grub_gpt_partition_type_bios_boot = GRUB_GPT_PARTITION_TYPE_BIOS_BOOT;
#endif
/* 512 << 7 = 65536 byte sectors. */
#define MAX_SECTOR_LOG 7
static struct grub_partition_map grub_gpt_partition_map;
grub_err_t
grub_gpt_partition_map_iterate (grub_disk_t disk,
grub_partition_iterate_hook_t hook,
void *hook_data)
{
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_compile_time (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. */
for (i = 0; i < 4; i++)
if (mbr.entries[i].type == GRUB_PC_PARTITION_TYPE_GPT_DISK)
break;
if (i == 4)
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;
part.parent = disk->partition;
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, hook_data))
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;
}
#ifdef GRUB_UTIL
/* Context for gpt_partition_map_embed. */
struct gpt_partition_map_embed_ctx
{
grub_disk_addr_t start, len;
};
/* Helper for gpt_partition_map_embed. */
static int
find_usable_region (grub_disk_t disk __attribute__ ((unused)),
const grub_partition_t p, void *data)
{
struct gpt_partition_map_embed_ctx *ctx = data;
struct grub_gpt_partentry gptdata;
grub_partition_t p2;
p2 = disk->partition;
disk->partition = p->parent;
if (grub_disk_read (disk, p->offset, p->index,
sizeof (gptdata), &gptdata))
{
disk->partition = p2;
return 0;
}
disk->partition = p2;
/* If there's an embed region, it is in a dedicated partition. */
if (! grub_memcmp (&gptdata.type, &grub_gpt_partition_type_bios_boot, 16))
{
ctx->start = p->start;
ctx->len = p->len;
return 1;
}
return 0;
}
static grub_err_t
gpt_partition_map_embed (struct grub_disk *disk, unsigned int *nsectors,
unsigned int max_nsectors,
grub_embed_type_t embed_type,
grub_disk_addr_t **sectors)
{
struct gpt_partition_map_embed_ctx ctx = {
.start = 0,
.len = 0
};
unsigned i;
grub_err_t err;
if (embed_type != GRUB_EMBED_PCBIOS)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"GPT currently supports only PC-BIOS embedding");
err = grub_gpt_partition_map_iterate (disk, find_usable_region, &ctx);
if (err)
return err;
if (ctx.len == 0)
return grub_error (GRUB_ERR_FILE_NOT_FOUND,
N_("this GPT partition label contains no BIOS Boot Partition;"
" embedding won't be possible"));
if (ctx.len < *nsectors)
return grub_error (GRUB_ERR_OUT_OF_RANGE,
N_("your BIOS Boot Partition is too small;"
" embedding won't be possible"));
*nsectors = ctx.len;
if (*nsectors > max_nsectors)
*nsectors = max_nsectors;
*sectors = grub_malloc (*nsectors * sizeof (**sectors));
if (!*sectors)
return grub_errno;
for (i = 0; i < *nsectors; i++)
(*sectors)[i] = ctx.start + i;
return GRUB_ERR_NONE;
}
#endif
/* Partition map type. */
static struct grub_partition_map grub_gpt_partition_map =
{
.name = "gpt",
.iterate = grub_gpt_partition_map_iterate,
#ifdef GRUB_UTIL
.embed = gpt_partition_map_embed
#endif
};
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);
}