arch/all-pc/boot/grub2-aros/grub-core/partmap/acorn.c

   1 /* acorn.c - Read Linux/ADFS partition tables.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2005,2007  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/acorn_filecore.h>
  25
  26 GRUB_MOD_LICENSE ("GPLv3+");
  27
  28 #define LINUX_NATIVE_MAGIC grub_cpu_to_le32 (0xdeafa1de)
  29 #define LINUX_SWAP_MAGIC   grub_cpu_to_le32 (0xdeafab1e)
  30 #define LINUX_MAP_ENTRIES  (512 / 12)
  31
  32 #define NONADFS_PARTITION_TYPE_LINUX 9
  33 #define NONADFS_PARTITION_TYPE_MASK 15
  34
  35 struct grub_acorn_boot_block
  36 {
  37   union
  38   {
  39     struct
  40     {
  41       grub_uint8_t misc[0x1C0];
  42       struct grub_filecore_disc_record disc_record;
  43       grub_uint8_t flags;
  44       grub_uint16_t start_cylinder;
  45       grub_uint8_t checksum;
  46     } __attribute__ ((packed, aligned));
  47     grub_uint8_t bin[0x200];
  48   };
  49 } __attribute__ ((packed, aligned));
  50
  51 struct linux_part
  52 {
  53   grub_uint32_t magic;
  54   grub_uint32_t start;
  55   grub_uint32_t size;
  56 };
  57
  58 static struct grub_partition_map grub_acorn_partition_map;
  59
  60 static grub_err_t
  61 acorn_partition_map_find (grub_disk_t disk, struct linux_part *m,
  62                           grub_disk_addr_t *sector)
  63 {
  64   struct grub_acorn_boot_block boot;
  65   grub_err_t err;
  66   unsigned int checksum = 0;
  67   unsigned int heads;
  68   unsigned int sectors_per_cylinder;
  69   int i;
  70
  71   err = grub_disk_read (disk, 0xC00 / GRUB_DISK_SECTOR_SIZE, 0,
  72                         sizeof (struct grub_acorn_boot_block),
  73                         &boot);
  74   if (err)
  75     return err;
  76
  77   if ((boot.flags & NONADFS_PARTITION_TYPE_MASK) != NONADFS_PARTITION_TYPE_LINUX)
  78     goto fail;
  79
  80   for (i = 0; i != 0x1ff; ++i)
  81     checksum = ((checksum & 0xff) + (checksum >> 8) + boot.bin[i]);
  82
  83   if ((grub_uint8_t) checksum != boot.checksum)
  84     goto fail;
  85
  86   heads = (boot.disc_record.heads
  87                     + ((boot.disc_record.lowsector >> 6) & 1));
  88   sectors_per_cylinder = boot.disc_record.secspertrack * heads;
  89   *sector = grub_le_to_cpu16 (boot.start_cylinder) * sectors_per_cylinder;
  90
  91   return grub_disk_read (disk, *sector, 0,
  92                          sizeof (struct linux_part) * LINUX_MAP_ENTRIES,
  93                          m);
  94
  95 fail:
  96   return grub_error (GRUB_ERR_BAD_PART_TABLE,
  97                      "Linux/ADFS partition map not found");
  98
  99 }
 100
 101
 102 static grub_err_t
 103 acorn_partition_map_iterate (grub_disk_t disk,
 104                              int (*hook) (grub_disk_t disk,
 105                                           const grub_partition_t partition))
 106 {
 107   struct grub_partition part;
 108   struct linux_part map[LINUX_MAP_ENTRIES];
 109   int i;
 110   grub_disk_addr_t sector = 0;
 111   grub_err_t err;
 112
 113   err = acorn_partition_map_find (disk, map, &sector);
 114   if (err)
 115     return err;
 116
 117   part.partmap = &grub_acorn_partition_map;
 118
 119   for (i = 0; i != LINUX_MAP_ENTRIES; ++i)
 120     {
 121       if (map[i].magic != LINUX_NATIVE_MAGIC
 122           && map[i].magic != LINUX_SWAP_MAGIC)
 123         return GRUB_ERR_NONE;
 124
 125       part.start = sector + map[i].start;
 126       part.len = map[i].size;
 127       part.offset = 6;
 128       part.number = part.index = i;
 129
 130       if (hook (disk, &part))
 131         return grub_errno;
 132     }
 133
 134   return GRUB_ERR_NONE;
 135 }
 136
 137 \f
 138
 139 /* Partition map type.  */
 140 static struct grub_partition_map grub_acorn_partition_map =
 141 {
 142   .name = "acorn",
 143   .iterate = acorn_partition_map_iterate,
 144 };
 145
 146 GRUB_MOD_INIT(part_acorn)
 147 {
 148   grub_partition_map_register (&grub_acorn_partition_map);
 149 }
 150
 151 GRUB_MOD_FINI(part_acorn)
 152 {
 153   grub_partition_map_unregister (&grub_acorn_partition_map);
 154 }