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 #define AMIGA_CHECKSUM_WORDS 128
  29
  30 struct grub_amiga_rdsk
  31 {
  32   /* "RDSK".  */
  33   grub_uint8_t magic[4];
  34 #define GRUB_AMIGA_RDSK_MAGIC "RDSK"
  35   grub_uint32_t size;
  36   grub_int32_t checksum;
  37   grub_uint32_t scsihost;
  38   grub_uint32_t blksz;
  39   grub_uint32_t flags;
  40   grub_uint32_t badblcklst;
  41   grub_uint32_t partitionlst;
  42   grub_uint32_t fslst;
  43
  44   grub_uint32_t unused[AMIGA_CHECKSUM_WORDS - 9];
  45 } GRUB_PACKED;
  46
  47 struct grub_amiga_partition
  48 {
  49   /* "PART".  */
  50   grub_uint8_t magic[4];
  51 #define GRUB_AMIGA_PART_MAGIC "PART"
  52   grub_uint32_t size;
  53   grub_int32_t checksum;
  54   grub_uint32_t scsihost;
  55   grub_uint32_t next;
  56   grub_uint32_t flags;
  57   grub_uint32_t unused1[2];
  58   grub_uint32_t devflags;
  59   grub_uint8_t namelen;
  60   grub_uint8_t name[31];
  61   grub_uint32_t unused2[15];
  62
  63   grub_uint32_t unused3[3];
  64   grub_uint32_t heads;
  65   grub_uint32_t unused4;
  66   grub_uint32_t block_per_track;
  67   grub_uint32_t unused5[3];
  68   grub_uint32_t lowcyl;
  69   grub_uint32_t highcyl;
  70
  71   grub_uint32_t firstcyl;
  72   grub_uint32_t unused[AMIGA_CHECKSUM_WORDS - 44];
  73 } GRUB_PACKED;
  74
  75 static struct grub_partition_map grub_amiga_partition_map;
  76
  77 \f
  78
  79 static grub_uint32_t
  80 amiga_partition_map_checksum (void *buf)
  81 {
  82   grub_uint32_t *ptr = buf;
  83   grub_uint32_t r = 0;
  84   grub_size_t sz;
  85   /* Fancy and quick way of checking sz >= 512 / 4 = 128.  */
  86   if (ptr[1] & ~grub_cpu_to_be32_compile_time (AMIGA_CHECKSUM_WORDS - 1))
  87     sz = AMIGA_CHECKSUM_WORDS;
  88   else
  89     sz = grub_be_to_cpu32 (ptr[1]);
  90
  91   for (; sz; sz--, ptr++)
  92     r += grub_be_to_cpu32 (*ptr);
  93
  94   return r;
  95 }
  96
  97 static grub_err_t
  98 amiga_partition_map_iterate (grub_disk_t disk,
  99                              grub_partition_iterate_hook_t hook,
 100                              void *hook_data)
 101 {
 102   struct grub_partition part;
 103   struct grub_amiga_rdsk rdsk;
 104   int partno = 0;
 105   int next = -1;
 106   unsigned pos;
 107
 108   /* The RDSK block is one of the first 15 blocks.  */
 109   for (pos = 0; pos < 15; pos++)
 110     {
 111       /* Read the RDSK block which is a descriptor for the entire disk.  */
 112       if (grub_disk_read (disk, pos, 0, sizeof (rdsk), &rdsk))
 113         return grub_errno;
 114
 115       if (grub_memcmp (rdsk.magic, GRUB_AMIGA_RDSK_MAGIC,
 116                        sizeof (rdsk.magic)) == 0
 117           && amiga_partition_map_checksum (&rdsk) == 0)
 118         {
 119           /* Found the first PART block.  */
 120           next = grub_be_to_cpu32 (rdsk.partitionlst);
 121           break;
 122         }
 123     }
 124
 125   if (next == -1)
 126     return grub_error (GRUB_ERR_BAD_PART_TABLE,
 127                        "Amiga partition map not found");
 128
 129   /* The end of the partition list is marked using "-1".  */
 130   while (next != -1)
 131     {
 132       struct grub_amiga_partition apart;
 133
 134       /* Read the RDSK block which is a descriptor for the entire disk.  */
 135       if (grub_disk_read (disk, next, 0, sizeof (apart), &apart))
 136         return grub_errno;
 137
 138       if (grub_memcmp (apart.magic, GRUB_AMIGA_PART_MAGIC,
 139                        sizeof (apart.magic)) != 0
 140           || amiga_partition_map_checksum (&apart) != 0)
 141         return grub_error (GRUB_ERR_BAD_PART_TABLE,
 142                            "invalid Amiga partition map");
 143       /* Calculate the first block and the size of the partition.  */
 144       part.start = (grub_be_to_cpu32 (apart.lowcyl)
 145                     * grub_be_to_cpu32 (apart.heads)
 146                     * grub_be_to_cpu32 (apart.block_per_track));
 147       part.len = ((grub_be_to_cpu32 (apart.highcyl)
 148                    - grub_be_to_cpu32 (apart.lowcyl) + 1)
 149                   * grub_be_to_cpu32 (apart.heads)
 150                   * grub_be_to_cpu32 (apart.block_per_track));
 151
 152       part.offset = next;
 153       part.number = partno;
 154       part.index = 0;
 155       part.partmap = &grub_amiga_partition_map;
 156
 157       if (hook (disk, &part, hook_data))
 158         return grub_errno;
 159
 160       next = grub_be_to_cpu32 (apart.next);
 161       partno++;
 162     }
 163
 164   return 0;
 165 }
 166
 167 \f
 168 /* Partition map type.  */
 169 static struct grub_partition_map grub_amiga_partition_map =
 170   {
 171     .name = "amiga",
 172     .iterate = amiga_partition_map_iterate,
 173   };
 174
 175 GRUB_MOD_INIT(part_amiga)
 176 {
 177   grub_partition_map_register (&grub_amiga_partition_map);
 178 }
 179
 180 GRUB_MOD_FINI(part_amiga)
 181 {
 182   grub_partition_map_unregister (&grub_amiga_partition_map);
 183 }