partmap/amiga.c

   1 /* amiga.c - Read amiga partition tables (RDB).  */
   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/disk.h>
  21 #include <grub/misc.h>
  22 #include <grub/mm.h>
  23 #include <grub/partition.h>
  24 #include <grub/dl.h>
  25
  26 struct grub_amiga_rdsk
  27 {
  28   /* "RDSK".  */
  29   grub_uint8_t magic[4];
  30   grub_uint32_t size;
  31   grub_int32_t checksum;
  32   grub_uint32_t scsihost;
  33   grub_uint32_t blksz;
  34   grub_uint32_t flags;
  35   grub_uint32_t badblcklst;
  36   grub_uint32_t partitionlst;
  37   grub_uint32_t fslst;
  38
  39   /* The other information is not important for us.  */
  40 } __attribute__ ((packed));
  41
  42 struct grub_amiga_partition
  43 {
  44   /* "PART".  */
  45   grub_uint8_t magic[4];
  46   grub_int32_t size;
  47   grub_int32_t checksum;
  48   grub_uint32_t scsihost;
  49   grub_uint32_t next;
  50   grub_uint32_t flags;
  51   grub_uint32_t unused1[2];
  52   grub_uint32_t devflags;
  53   grub_uint8_t namelen;
  54   grub_uint8_t name[31];
  55   grub_uint32_t unused2[15];
  56
  57   grub_uint32_t unused3[3];
  58   grub_uint32_t heads;
  59   grub_uint32_t unused4;
  60   grub_uint32_t block_per_track;
  61   grub_uint32_t unused5[3];
  62   grub_uint32_t lowcyl;
  63   grub_uint32_t highcyl;
  64
  65   grub_uint32_t firstcyl;
  66 } __attribute__ ((packed));
  67
  68 static struct grub_partition_map grub_amiga_partition_map;
  69
  70 \f
  71
  72 static grub_err_t
  73 amiga_partition_map_iterate (grub_disk_t disk,
  74                              int (*hook) (grub_disk_t disk,
  75                                           const grub_partition_t partition))
  76 {
  77   struct grub_partition part;
  78   struct grub_amiga_rdsk rdsk;
  79   int partno = 0;
  80   int next = -1;
  81   unsigned pos;
  82
  83   /* The RDSK block is one of the first 15 blocks.  */
  84   for (pos = 0; pos < 15; pos++)
  85     {
  86       /* Read the RDSK block which is a descriptor for the entire disk.  */
  87       if (grub_disk_read (disk, pos, 0, sizeof (rdsk), &rdsk))
  88         return grub_errno;
  89
  90       if (grub_strcmp ((char *) rdsk.magic, "RDSK") == 0)
  91         {
  92           /* Found the first PART block.  */
  93           next = grub_be_to_cpu32 (rdsk.partitionlst);
  94           break;
  95         }
  96     }
  97
  98   if (next == -1)
  99     return grub_error (GRUB_ERR_BAD_PART_TABLE,
 100                        "Amiga partition map not found.");
 101
 102   part.data = 0;
 103
 104   /* The end of the partition list is marked using "-1".  */
 105   while (next != -1)
 106     {
 107       struct grub_amiga_partition apart;
 108
 109       /* Read the RDSK block which is a descriptor for the entire disk.  */
 110       if (grub_disk_read (disk, next, 0, sizeof (apart), &apart))
 111         return grub_errno;
 112
 113       /* Calculate the first block and the size of the partition.  */
 114       part.start = (grub_be_to_cpu32 (apart.lowcyl)
 115                     * grub_be_to_cpu32 (apart.heads)
 116                     * grub_be_to_cpu32 (apart.block_per_track));
 117       part.len = ((grub_be_to_cpu32 (apart.highcyl)
 118                    - grub_be_to_cpu32 (apart.lowcyl) + 1)
 119                   * grub_be_to_cpu32 (apart.heads)
 120                   * grub_be_to_cpu32 (apart.block_per_track));
 121
 122       part.offset = (grub_off_t) next * 512;
 123       part.number = partno;
 124       part.partmap = &grub_amiga_partition_map;
 125
 126       if (hook (disk, &part))
 127         return grub_errno;
 128
 129       next = grub_be_to_cpu32 (apart.next);
 130       partno++;
 131     }
 132
 133   return 0;
 134 }
 135
 136 \f
 137 /* Partition map type.  */
 138 static struct grub_partition_map grub_amiga_partition_map =
 139   {
 140     .name = "amiga_partition_map",
 141     .iterate = amiga_partition_map_iterate,
 142   };
 143
 144 GRUB_MOD_INIT(amiga_partition_map)
 145 {
 146   grub_partition_map_register (&grub_amiga_partition_map);
 147 }
 148
 149 GRUB_MOD_FINI(amiga_partition_map)
 150 {
 151   grub_partition_map_unregister (&grub_amiga_partition_map);
 152 }