arch/common/boot/grub2/partmap/pc.c

   1 /* pc.c - Read PC style partition tables.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2002,2004,2005,2006,2007  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/partition.h>
  21 #include <grub/pc_partition.h>
  22 #include <grub/disk.h>
  23 #include <grub/mm.h>
  24 #include <grub/misc.h>
  25 #include <grub/dl.h>
  26
  27 /* RDB partition tables for AROS */
  28 struct grub_partition_map *grub_rdb_partition_map = NULL;
  29
  30 static struct grub_partition_map grub_pc_partition_map;
  31
  32 #ifndef GRUB_UTIL
  33 static grub_dl_t my_mod;
  34 #endif
  35 \f
  36
  37 /* Parse the partition representation in STR and return a partition.  */
  38 static grub_partition_t
  39 grub_partition_parse (const char *str)
  40 {
  41   grub_partition_t p;
  42   struct grub_pc_partition *pcdata;
  43
  44   char *s = (char *) str;
  45
  46   p = (grub_partition_t) grub_malloc (sizeof (*p));
  47   if (! p)
  48     return 0;
  49
  50   pcdata = (struct grub_pc_partition *) grub_malloc (sizeof (*pcdata));
  51   if (! pcdata)
  52     goto fail;
  53
  54   p->data = pcdata;
  55   p->partmap = &grub_pc_partition_map;
  56
  57   /* Initialize some of the fields with invalid values.  */
  58   pcdata->bsd_part = pcdata->dos_type = pcdata->bsd_type = p->index = -1;
  59
  60   /* Get the DOS partition number. The number is counted from one for
  61      the user interface, and from zero internally.  */
  62   pcdata->dos_part = grub_strtoul (s, &s, 0) - 1;
  63
  64   if (grub_errno)
  65     {
  66       /* Not found. Maybe only a BSD label is specified.  */
  67       pcdata->dos_part = -1;
  68       grub_errno = GRUB_ERR_NONE;
  69     }
  70   else if (*s == ',')
  71     s++;
  72
  73   if (*s)
  74     {
  75       if (*s >= 'a' && *s <= 'h')
  76         {
  77           pcdata->bsd_part = *s - 'a';
  78           s++;
  79         }
  80
  81       if (*s)
  82         goto fail;
  83     }
  84
  85   if (pcdata->dos_part == -1 && pcdata->bsd_part == -1)
  86     goto fail;
  87
  88   return p;
  89
  90  fail:
  91   grub_free (p);
  92   grub_free (pcdata);
  93   grub_error (GRUB_ERR_BAD_FILENAME, "invalid partition");
  94   return 0;
  95 }
  96
  97 static grub_err_t
  98 pc_partition_map_iterate (grub_disk_t disk,
  99                           int (*hook) (grub_disk_t disk,
 100                                        const grub_partition_t partition))
 101 {
 102   struct grub_partition p;
 103   struct grub_pc_partition pcdata;
 104   struct grub_pc_partition_mbr mbr;
 105   struct grub_pc_partition_disk_label label;
 106   struct grub_disk raw;
 107
 108   /* Enforce raw disk access.  */
 109   raw = *disk;
 110   raw.partition = 0;
 111
 112   p.offset = 0;
 113   pcdata.ext_offset = 0;
 114   pcdata.dos_part = -1;
 115   p.data = &pcdata;
 116   p.partmap = &grub_pc_partition_map;
 117
 118   while (1)
 119     {
 120       int i;
 121       struct grub_pc_partition_entry *e;
 122
 123       /* Read the MBR.  */
 124       if (grub_disk_read (&raw, p.offset, 0, sizeof (mbr), (char *) &mbr))
 125         goto finish;
 126
 127       /* Check if it is valid.  */
 128       if (mbr.signature != grub_cpu_to_le16 (GRUB_PC_PARTITION_SIGNATURE))
 129         return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
 130
 131       /* Analyze DOS partitions.  */
 132       for (p.index = 0; p.index < 4; p.index++)
 133         {
 134           e = mbr.entries + p.index;
 135
 136           p.start = p.offset + grub_le_to_cpu32 (e->start);
 137           p.len = grub_le_to_cpu32 (e->length);
 138           pcdata.bsd_part = -1;
 139           pcdata.dos_type = e->type;
 140           pcdata.bsd_type = -1;
 141
 142           grub_dprintf ("partition",
 143                         "partition %d: flag 0x%x, type 0x%x, start 0x%llx, len 0x%llx\n",
 144                         p.index, e->flag, pcdata.dos_type,
 145                         (unsigned long long) p.start,
 146                         (unsigned long long) p.len);
 147
 148           /* If this is a GPT partition, this MBR is just a dummy.  */
 149           if (e->type == GRUB_PC_PARTITION_TYPE_GPT_DISK && p.index == 0)
 150             return grub_error (GRUB_ERR_BAD_PART_TABLE, "dummy mbr");
 151
 152           /* If this partition is a normal one, call the hook.  */
 153           if (! grub_pc_partition_is_empty (e->type)
 154               && ! grub_pc_partition_is_extended (e->type))
 155             {
 156               pcdata.dos_part++;
 157
 158
 159
 160         /* Check if this is a RDB partition table.  */
 161         if (grub_rdb_partition_map && grub_pc_partition_is_rdb(e->type))
 162         {
 163             struct grub_partition p2;
 164             struct grub_disk raw2;
 165             int ok = 0;
 166
 167             auto int rdb_hook(grub_disk_t disk, const grub_partition_t p);
 168
 169             int rdb_hook(grub_disk_t disk __attribute__((unused)),
 170                  const grub_partition_t part)
 171             {
 172                 p2 = *part;
 173                 pcdata.bsd_part = part->index;
 174
 175                 p2.start  += p.start;
 176                 p2.offset += p.offset;
 177                 p2.data    = &pcdata;
 178                 p2.partmap = &grub_pc_partition_map;
 179
 180                 grub_dprintf("partition", "RDB part %c start=%ld\n",
 181                        (char)('a' + part->index), (long)p2.start);
 182
 183                 ok = hook(disk, &p2);
 184                 return ok;
 185             }
 186
 187             raw2 = raw;
 188             raw2.partition = &p;
 189
 190             grub_rdb_partition_map->iterate(&raw2, rdb_hook);
 191             if (ok)
 192                 goto finish;
 193         }
 194         else
 195             if (hook (disk, &p))
 196                 return 1;
 197
 198               /* Check if this is a BSD partition.  */
 199               if (grub_pc_partition_is_bsd (e->type))
 200                 {
 201                   /* Check if the BSD label is within the DOS partition.  */
 202                   if (p.len <= GRUB_PC_PARTITION_BSD_LABEL_SECTOR)
 203                     return grub_error (GRUB_ERR_BAD_PART_TABLE,
 204                                        "no space for disk label");
 205
 206                   /* Read the BSD label.  */
 207                   if (grub_disk_read (&raw,
 208                                       (p.start
 209                                        + GRUB_PC_PARTITION_BSD_LABEL_SECTOR),
 210                                       0,
 211                                       sizeof (label),
 212                                       (char *) &label))
 213                     goto finish;
 214
 215                   /* Check if it is valid.  */
 216                   if (label.magic
 217                       != grub_cpu_to_le32 (GRUB_PC_PARTITION_BSD_LABEL_MAGIC))
 218                     return grub_error (GRUB_ERR_BAD_PART_TABLE,
 219                                        "invalid disk label magic 0x%x",
 220                                        label.magic);
 221
 222                   for (pcdata.bsd_part = 0;
 223                        pcdata.bsd_part < grub_cpu_to_le16 (label.num_partitions);
 224                        pcdata.bsd_part++)
 225                     {
 226                       struct grub_pc_partition_bsd_entry *be
 227                         = label.entries + pcdata.bsd_part;
 228
 229                       p.start = grub_le_to_cpu32 (be->offset);
 230                       p.len = grub_le_to_cpu32 (be->size);
 231                       pcdata.bsd_type = be->fs_type;
 232
 233                       if (be->fs_type != GRUB_PC_PARTITION_BSD_TYPE_UNUSED)
 234                         if (hook (disk, &p))
 235                           return 1;
 236                     }
 237                 }
 238             }
 239           else if (pcdata.dos_part < 4)
 240             /* If this partition is a logical one, shouldn't increase the
 241                partition number.  */
 242             pcdata.dos_part++;
 243         }
 244
 245       /* Find an extended partition.  */
 246       for (i = 0; i < 4; i++)
 247         {
 248           e = mbr.entries + i;
 249
 250           if (grub_pc_partition_is_extended (e->type))
 251             {
 252               p.offset = pcdata.ext_offset + grub_le_to_cpu32 (e->start);
 253               if (! pcdata.ext_offset)
 254                 pcdata.ext_offset = p.offset;
 255
 256               break;
 257             }
 258         }
 259
 260       /* If no extended partition, the end.  */
 261       if (i == 4)
 262         break;
 263     }
 264
 265  finish:
 266   return grub_errno;
 267 }
 268
 269
 270 static grub_partition_t
 271 pc_partition_map_probe (grub_disk_t disk, const char *str)
 272 {
 273   grub_partition_t p;
 274   struct grub_pc_partition *pcdata;
 275
 276   auto int find_func (grub_disk_t d, const grub_partition_t partition);
 277
 278   int find_func (grub_disk_t d __attribute__ ((unused)),
 279                  const grub_partition_t partition)
 280     {
 281       struct grub_pc_partition *partdata = partition->data;
 282
 283       if ((pcdata->dos_part == partdata->dos_part || pcdata->dos_part == -1)
 284           && pcdata->bsd_part == partdata->bsd_part)
 285         {
 286           grub_memcpy (p, partition, sizeof (*p));
 287           p->data = pcdata;
 288           grub_memcpy (pcdata, partdata, sizeof (*pcdata));
 289           return 1;
 290         }
 291
 292       return 0;
 293     }
 294
 295   p = grub_partition_parse (str);
 296   if (! p)
 297     return 0;
 298
 299   pcdata = p->data;
 300   pc_partition_map_iterate (disk, find_func);
 301   if (grub_errno)
 302     goto fail;
 303
 304   if (p->index < 0)
 305     {
 306       grub_error (GRUB_ERR_BAD_DEVICE, "no such partition");
 307       goto fail;
 308     }
 309
 310   return p;
 311
 312  fail:
 313   grub_free (p);
 314   grub_free (pcdata);
 315   return 0;
 316 }
 317
 318
 319 static char *
 320 pc_partition_map_get_name (const grub_partition_t p)
 321 {
 322   char *name;
 323   struct grub_pc_partition *pcdata = p->data;
 324
 325   name = grub_malloc (13);
 326   if (! name)
 327     return 0;
 328
 329   if (pcdata->bsd_part < 0)
 330     grub_sprintf (name, "%d", pcdata->dos_part + 1);
 331   else if (pcdata->dos_part < 0)
 332     grub_sprintf (name, "%c", pcdata->bsd_part + 'a');
 333   else
 334     grub_sprintf (name, "%d,%c", pcdata->dos_part + 1, pcdata->bsd_part + 'a');
 335
 336   return name;
 337 }
 338
 339 \f
 340 /* Partition map type.  */
 341 static struct grub_partition_map grub_pc_partition_map =
 342   {
 343     .name = "pc_partition_map",
 344     .iterate = pc_partition_map_iterate,
 345     .probe = pc_partition_map_probe,
 346     .get_name = pc_partition_map_get_name
 347   };
 348
 349 GRUB_MOD_INIT(pc_partition_map)
 350 {
 351   grub_partition_map_register (&grub_pc_partition_map);
 352 #ifndef GRUB_UTIL
 353   my_mod = mod;
 354 #endif
 355 }
 356
 357 GRUB_MOD_FINI(pc_partition_map)
 358 {
 359   grub_partition_map_unregister (&grub_pc_partition_map);
 360 }