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

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2002,2005,2006,2007,2011  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/partition.h>
  20 #include <grub/disk.h>
  21 #include <grub/mm.h>
  22 #include <grub/misc.h>
  23 #include <grub/dl.h>
  24 #include <grub/symbol.h>
  25 #include <grub/types.h>
  26 #include <grub/err.h>
  27
  28 GRUB_MOD_LICENSE ("GPLv3+");
  29
  30 #define DVH_MAGIC 0x0be5a941
  31
  32 struct grub_dvh_partition_descriptor
  33 {
  34   grub_uint32_t length;
  35   grub_uint32_t start;
  36   grub_uint32_t type;
  37 } __attribute__ ((packed));
  38
  39 struct grub_dvh_block
  40 {
  41   grub_uint32_t magic;
  42   grub_uint8_t unused[308];
  43   struct grub_dvh_partition_descriptor parts[16];
  44   grub_uint32_t checksum;
  45   grub_uint32_t unused2;
  46 } __attribute__ ((packed));
  47
  48 static struct grub_partition_map grub_dvh_partition_map;
  49
  50 /* Verify checksum (true=ok).  */
  51 static int
  52 grub_dvh_is_valid (grub_uint32_t *label)
  53 {
  54   grub_uint32_t *pos;
  55   grub_uint32_t sum = 0;
  56
  57   for (pos = label;
  58        pos < (label + sizeof (struct grub_dvh_block) / 4);
  59        pos++)
  60     sum += *pos;
  61
  62   return ! sum;
  63 }
  64
  65 static grub_err_t
  66 dvh_partition_map_iterate (grub_disk_t disk,
  67                            int (*hook) (grub_disk_t disk,
  68                                         const grub_partition_t partition))
  69 {
  70   struct grub_partition p;
  71   union
  72   {
  73     struct grub_dvh_block dvh;
  74     grub_uint32_t raw[0];
  75   } block;
  76   unsigned partnum;
  77   grub_err_t err;
  78
  79   p.partmap = &grub_dvh_partition_map;
  80   err = grub_disk_read (disk, 0, 0, sizeof (struct grub_dvh_block),
  81                         &block);
  82   if (err)
  83     return err;
  84
  85   if (DVH_MAGIC != grub_be_to_cpu32 (block.dvh.magic))
  86     return grub_error (GRUB_ERR_BAD_PART_TABLE, "not a dvh partition table");
  87
  88   if (! grub_dvh_is_valid (block.raw))
  89       return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid checksum");
  90
  91   /* Maybe another error value would be better, because partition
  92      table _is_ recognized but invalid.  */
  93   for (partnum = 0; partnum < ARRAY_SIZE (block.dvh.parts); partnum++)
  94     {
  95       if (block.dvh.parts[partnum].length == 0)
  96         continue;
  97
  98       if (partnum == 10)
  99         continue;
 100
 101       p.start = grub_be_to_cpu32 (block.dvh.parts[partnum].start);
 102       p.len = grub_be_to_cpu32 (block.dvh.parts[partnum].length);
 103       p.number = p.index = partnum;
 104       if (hook (disk, &p))
 105         break;
 106     }
 107
 108   return grub_errno;
 109 }
 110
 111
 112 /* Partition map type.  */
 113 static struct grub_partition_map grub_dvh_partition_map =
 114   {
 115     .name = "dvh",
 116     .iterate = dvh_partition_map_iterate,
 117   };
 118
 119 GRUB_MOD_INIT(part_dvh)
 120 {
 121   grub_partition_map_register (&grub_dvh_partition_map);
 122 }
 123
 124 GRUB_MOD_FINI(part_dvh)
 125 {
 126   grub_partition_map_unregister (&grub_dvh_partition_map);
 127 }
 128