arch/all-pc/boot/grub2-aros/grub-core/partmap/gpt.c

   1 /* gpt.c - Read GUID Partition Tables (GPT).  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2002,2005,2006,2007,2008  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/disk.h>
  21 #include <grub/misc.h>
  22 #include <grub/mm.h>
  23 #include <grub/partition.h>
  24 #include <grub/dl.h>
  25 #include <grub/msdos_partition.h>
  26 #include <grub/gpt_partition.h>
  27 #include <grub/i18n.h>
  28
  29 GRUB_MOD_LICENSE ("GPLv3+");
  30
  31 static grub_uint8_t grub_gpt_magic[8] =
  32   {
  33     0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54
  34   };
  35
  36 static const grub_gpt_part_type_t grub_gpt_partition_type_empty = GRUB_GPT_PARTITION_TYPE_EMPTY;
  37
  38 #ifdef GRUB_UTIL
  39 static const grub_gpt_part_type_t grub_gpt_partition_type_bios_boot = GRUB_GPT_PARTITION_TYPE_BIOS_BOOT;
  40 #endif
  41
  42 /* 512 << 7 = 65536 byte sectors.  */
  43 #define MAX_SECTOR_LOG 7
  44
  45 static struct grub_partition_map grub_gpt_partition_map;
  46
  47 \f
  48
  49 grub_err_t
  50 grub_gpt_partition_map_iterate (grub_disk_t disk,
  51                                 int (*hook) (grub_disk_t disk,
  52                                              const grub_partition_t partition))
  53 {
  54   struct grub_partition part;
  55   struct grub_gpt_header gpt;
  56   struct grub_gpt_partentry entry;
  57   struct grub_msdos_partition_mbr mbr;
  58   grub_uint64_t entries;
  59   unsigned int i;
  60   int last_offset = 0;
  61   int sector_log = 0;
  62
  63   /* Read the protective MBR.  */
  64   if (grub_disk_read (disk, 0, 0, sizeof (mbr), &mbr))
  65     return grub_errno;
  66
  67   /* Check if it is valid.  */
  68   if (mbr.signature != grub_cpu_to_le16 (GRUB_PC_PARTITION_SIGNATURE))
  69     return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
  70
  71   /* Make sure the MBR is a protective MBR and not a normal MBR.  */
  72   for (i = 0; i < 4; i++)
  73     if (mbr.entries[i].type == GRUB_PC_PARTITION_TYPE_GPT_DISK)
  74       break;
  75   if (i == 4)
  76     return grub_error (GRUB_ERR_BAD_PART_TABLE, "no GPT partition map found");
  77
  78   /* Read the GPT header.  */
  79   for (sector_log = 0; sector_log < MAX_SECTOR_LOG; sector_log++)
  80     {
  81       if (grub_disk_read (disk, 1 << sector_log, 0, sizeof (gpt), &gpt))
  82         return grub_errno;
  83
  84       if (grub_memcmp (gpt.magic, grub_gpt_magic, sizeof (grub_gpt_magic)) == 0)
  85         break;
  86     }
  87   if (sector_log == MAX_SECTOR_LOG)
  88     return grub_error (GRUB_ERR_BAD_PART_TABLE, "no valid GPT header");
  89
  90   grub_dprintf ("gpt", "Read a valid GPT header\n");
  91
  92   entries = grub_le_to_cpu64 (gpt.partitions) << sector_log;
  93   for (i = 0; i < grub_le_to_cpu32 (gpt.maxpart); i++)
  94     {
  95       if (grub_disk_read (disk, entries, last_offset,
  96                           sizeof (entry), &entry))
  97         return grub_errno;
  98
  99       if (grub_memcmp (&grub_gpt_partition_type_empty, &entry.type,
 100                        sizeof (grub_gpt_partition_type_empty)))
 101         {
 102           /* Calculate the first block and the size of the partition.  */
 103           part.start = grub_le_to_cpu64 (entry.start) << sector_log;
 104           part.len = (grub_le_to_cpu64 (entry.end)
 105                       - grub_le_to_cpu64 (entry.start) + 1)  << sector_log;
 106           part.offset = entries;
 107           part.number = i;
 108           part.index = last_offset;
 109           part.partmap = &grub_gpt_partition_map;
 110           part.parent = disk->partition;
 111
 112           grub_dprintf ("gpt", "GPT entry %d: start=%lld, length=%lld\n", i,
 113                         (unsigned long long) part.start,
 114                         (unsigned long long) part.len);
 115
 116           if (hook (disk, &part))
 117             return grub_errno;
 118         }
 119
 120       last_offset += grub_le_to_cpu32 (gpt.partentry_size);
 121       if (last_offset == GRUB_DISK_SECTOR_SIZE)
 122         {
 123           last_offset = 0;
 124           entries++;
 125         }
 126     }
 127
 128   return GRUB_ERR_NONE;
 129 }
 130
 131 #ifdef GRUB_UTIL
 132 static grub_err_t
 133 gpt_partition_map_embed (struct grub_disk *disk_, unsigned int *nsectors,
 134                          unsigned int max_nsectors,
 135                          grub_embed_type_t embed_type,
 136                          grub_disk_addr_t **sectors)
 137 {
 138   grub_disk_addr_t start = 0, len = 0;
 139   unsigned i;
 140   grub_err_t err;
 141
 142   auto int NESTED_FUNC_ATTR find_usable_region (grub_disk_t disk,
 143                                                 const grub_partition_t p);
 144   int NESTED_FUNC_ATTR find_usable_region (grub_disk_t disk __attribute__ ((unused)),
 145                                            const grub_partition_t p)
 146   {
 147     struct grub_gpt_partentry gptdata;
 148     grub_partition_t p2;
 149
 150     p2 = disk->partition;
 151     disk->partition = p->parent;
 152     if (grub_disk_read (disk, p->offset, p->index,
 153                         sizeof (gptdata), &gptdata))
 154       {
 155         disk->partition = p2;
 156         return 0;
 157       }
 158     disk->partition = p2;
 159
 160     /* If there's an embed region, it is in a dedicated partition.  */
 161     if (! grub_memcmp (&gptdata.type, &grub_gpt_partition_type_bios_boot, 16))
 162       {
 163         start = p->start;
 164         len = p->len;
 165         return 1;
 166       }
 167
 168       return 0;
 169     }
 170
 171   if (embed_type != GRUB_EMBED_PCBIOS)
 172     return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 173                        "GPT currently supports only PC-BIOS embedding");
 174
 175   err = grub_gpt_partition_map_iterate (disk_, find_usable_region);
 176   if (err)
 177     return err;
 178
 179   if (len == 0)
 180     return grub_error (GRUB_ERR_FILE_NOT_FOUND,
 181                        N_("this GPT partition label contains no BIOS Boot Partition;"
 182                           " embedding won't be possible"));
 183
 184   if (len < *nsectors)
 185     return grub_error (GRUB_ERR_OUT_OF_RANGE,
 186                        N_("your BIOS Boot Partition is too small;"
 187                           " embedding won't be possible"));
 188
 189   *nsectors = len;
 190   if (*nsectors > max_nsectors)
 191     *nsectors = max_nsectors;
 192   *sectors = grub_malloc (*nsectors * sizeof (**sectors));
 193   if (!*sectors)
 194     return grub_errno;
 195   for (i = 0; i < *nsectors; i++)
 196     (*sectors)[i] = start + i;
 197
 198   return GRUB_ERR_NONE;
 199 }
 200 #endif
 201
 202 \f
 203 /* Partition map type.  */
 204 static struct grub_partition_map grub_gpt_partition_map =
 205   {
 206     .name = "gpt",
 207     .iterate = grub_gpt_partition_map_iterate,
 208 #ifdef GRUB_UTIL
 209     .embed = gpt_partition_map_embed
 210 #endif
 211   };
 212
 213 GRUB_MOD_INIT(part_gpt)
 214 {
 215   grub_partition_map_register (&grub_gpt_partition_map);
 216 }
 217
 218 GRUB_MOD_FINI(part_gpt)
 219 {
 220   grub_partition_map_unregister (&grub_gpt_partition_map);
 221 }