arch/all-pc/boot/grub2-aros/grub-core/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 GRUB_MOD_LICENSE ("GPLv3+");
  27
  28 struct grub_amiga_rdsk
  29 {
  30   /* "RDSK".  */
  31   grub_uint8_t magic[4];
  32 #define GRUB_AMIGA_RDSK_MAGIC "RDSK"
  33   grub_uint32_t size;
  34   grub_int32_t checksum;
  35   grub_uint32_t scsihost;
  36   grub_uint32_t blksz;
  37   grub_uint32_t flags;
  38   grub_uint32_t badblcklst;
  39   grub_uint32_t partitionlst;
  40   grub_uint32_t fslst;
  41
  42   grub_uint32_t unused[128 - 9];
  43 } __attribute__ ((packed));
  44
  45 struct grub_amiga_partition
  46 {
  47   /* "PART".  */
  48   grub_uint8_t magic[4];
  49 #define GRUB_AMIGA_PART_MAGIC "PART"
  50   grub_int32_t size;
  51   grub_int32_t checksum;
  52   grub_uint32_t scsihost;
  53   grub_uint32_t next;
  54   grub_uint32_t flags;
  55   grub_uint32_t unused1[2];
  56   grub_uint32_t devflags;
  57   grub_uint8_t namelen;
  58   grub_uint8_t name[31];
  59   grub_uint32_t unused2[15];
  60
  61   grub_uint32_t unused3[3];
  62   grub_uint32_t heads;
  63   grub_uint32_t unused4;
  64   grub_uint32_t block_per_track;
  65   grub_uint32_t unused5[3];
  66   grub_uint32_t lowcyl;
  67   grub_uint32_t highcyl;
  68
  69   grub_uint32_t firstcyl;
  70   grub_uint32_t unused[128 - 44];
  71 } __attribute__ ((packed));
  72
  73 static struct grub_partition_map grub_amiga_partition_map;
  74
  75 \f
  76
  77 static grub_uint32_t
  78 amiga_partition_map_checksum (void *buf, grub_size_t sz)
  79 {
  80   grub_uint32_t *ptr = buf;
  81   grub_uint32_t r = 0;
  82   sz /= sizeof (grub_uint32_t);
  83   for (; sz; sz--, ptr++)
  84     r += grub_be_to_cpu32 (*ptr);
  85   return r;
  86 }
  87
  88 static grub_err_t
  89 amiga_partition_map_iterate (grub_disk_t disk,
  90                              int (*hook) (grub_disk_t disk,
  91                                           const grub_partition_t partition))
  92 {
  93   struct grub_partition part;
  94   struct grub_amiga_rdsk rdsk;
  95   int partno = 0;
  96   int next = -1;
  97   unsigned pos;
  98
  99   /* The RDSK block is one of the first 15 blocks.  */
 100   for (pos = 0; pos < 15; pos++)
 101     {
 102       /* Read the RDSK block which is a descriptor for the entire disk.  */
 103       if (grub_disk_read (disk, pos, 0, sizeof (rdsk), &rdsk))
 104         return grub_errno;
 105
 106       if (grub_memcmp (rdsk.magic, GRUB_AMIGA_RDSK_MAGIC,
 107                        sizeof (rdsk.magic)) == 0
 108           && amiga_partition_map_checksum (&rdsk, sizeof (rdsk)) == 0)
 109         {
 110           /* Found the first PART block.  */
 111           next = grub_be_to_cpu32 (rdsk.partitionlst);
 112           break;
 113         }
 114     }
 115
 116   if (next == -1)
 117     return grub_error (GRUB_ERR_BAD_PART_TABLE,
 118                        "Amiga partition map not found");
 119
 120   /* The end of the partition list is marked using "-1".  */
 121   while (next != -1)
 122     {
 123       struct grub_amiga_partition apart;
 124
 125       /* Read the RDSK block which is a descriptor for the entire disk.  */
 126       if (grub_disk_read (disk, next, 0, sizeof (apart), &apart))
 127         return grub_errno;
 128
 129       if (grub_memcmp (apart.magic, GRUB_AMIGA_PART_MAGIC,
 130                        sizeof (apart.magic)) != 0
 131           || amiga_partition_map_checksum (&apart, sizeof (apart)) != 0)
 132         return grub_error (GRUB_ERR_BAD_PART_TABLE,
 133                            "invalid Amiga partition map");
 134       /* Calculate the first block and the size of the partition.  */
 135       part.start = (grub_be_to_cpu32 (apart.lowcyl)
 136                     * grub_be_to_cpu32 (apart.heads)
 137                     * grub_be_to_cpu32 (apart.block_per_track));
 138       part.len = ((grub_be_to_cpu32 (apart.highcyl)
 139                    - grub_be_to_cpu32 (apart.lowcyl) + 1)
 140                   * grub_be_to_cpu32 (apart.heads)
 141                   * grub_be_to_cpu32 (apart.block_per_track));
 142
 143       part.offset = (grub_off_t) next * 512;
 144       part.number = partno;
 145       part.index = 0;
 146       part.partmap = &grub_amiga_partition_map;
 147
 148       if (hook (disk, &part))
 149         return grub_errno;
 150
 151       next = grub_be_to_cpu32 (apart.next);
 152       partno++;
 153     }
 154
 155   return 0;
 156 }
 157
 158 \f
 159 /* Partition map type.  */
 160 static struct grub_partition_map grub_amiga_partition_map =
 161   {
 162     .name = "amiga",
 163     .iterate = amiga_partition_map_iterate,
 164   };
 165
 166 GRUB_MOD_INIT(part_amiga)
 167 {
 168   grub_partition_map_register (&grub_amiga_partition_map);
 169 }
 170
 171 GRUB_MOD_FINI(part_amiga)
 172 {
 173   grub_partition_map_unregister (&grub_amiga_partition_map);
 174 }