partmap/bsdlabel.c

   1 /* bsdlabel.c - Read BSD style partition tables.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2002,2004,2005,2006,2007,2008,2009  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/bsdlabel.h>
  22 #include <grub/disk.h>
  23 #include <grub/mm.h>
  24 #include <grub/misc.h>
  25 #include <grub/dl.h>
  26
  27 static struct grub_partition_map grub_bsdlabel_partition_map;
  28 \f
  29
  30 static grub_err_t
  31 bsdlabel_partition_map_iterate (grub_disk_t disk,
  32                           int (*hook) (grub_disk_t disk,
  33                                        const grub_partition_t partition))
  34 {
  35   struct grub_pc_partition_disk_label label;
  36   struct grub_partition p;
  37   grub_partition_t part;
  38   grub_disk_addr_t delta = 0;
  39
  40   /* BSDLabel offsets are absolute even when it's embed inside partition.  */
  41   for (part = disk->partition; part; part = part->parent)
  42     delta += grub_partition_get_start (part);
  43
  44   /* Read the BSD label.  */
  45   if (grub_disk_read (disk, GRUB_PC_PARTITION_BSD_LABEL_SECTOR,
  46                       0, sizeof (label), &label))
  47     goto finish;
  48
  49   /* Check if it is valid.  */
  50   if (label.magic != grub_cpu_to_le32 (GRUB_PC_PARTITION_BSD_LABEL_MAGIC))
  51     return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
  52   for (p.number = 0;
  53        p.number < grub_cpu_to_le16 (label.num_partitions);
  54        p.number++)
  55     {
  56       struct grub_pc_partition_bsd_entry *be
  57         = label.entries + p.number;
  58
  59       p.start = grub_le_to_cpu32 (be->offset) - delta;
  60       p.len = grub_le_to_cpu32 (be->size);
  61       p.offset = GRUB_PC_PARTITION_BSD_LABEL_SECTOR;
  62       p.partmap = &grub_bsdlabel_partition_map;
  63       p.data = 0;
  64
  65       if (be->fs_type != GRUB_PC_PARTITION_BSD_TYPE_UNUSED)
  66         if (hook (disk, &p))
  67           return 1;
  68     }
  69  finish:
  70   return grub_errno;
  71 }
  72
  73 \f
  74 /* Partition map type.  */
  75 static struct grub_partition_map grub_bsdlabel_partition_map =
  76   {
  77     .name = "bsdlabel_partition_map",
  78     .iterate = bsdlabel_partition_map_iterate,
  79   };
  80
  81 GRUB_MOD_INIT(bsdlabel_partition_map)
  82 {
  83   grub_partition_map_register (&grub_bsdlabel_partition_map);
  84 }
  85
  86 GRUB_MOD_FINI(bsdlabel_partition_map)
  87 {
  88   grub_partition_map_unregister (&grub_bsdlabel_partition_map);
  89 }