diff options
Diffstat (limited to 'grub-core/partmap/gpt.c')
| -rw-r--r-- | grub-core/partmap/gpt.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/grub-core/partmap/gpt.c b/grub-core/partmap/gpt.c new file mode 100644 index 0000000..075cc96 --- /dev/null +++ b/grub-core/partmap/gpt.c @@ -0,0 +1,238 @@ +/* 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> +#ifdef GRUB_UTIL +#include <grub/emu/misc.h> +#endif + +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, + int warn_short) +{ + 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 < GRUB_MIN_RECOMMENDED_MBR_GAP) + grub_util_warn ("Your BIOS Boot Partition is under 1 MiB, please increase its size."); + + 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_calloc (*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); +} |