fs/partitions/amiga.c

   1 /*
   2  *  fs/partitions/amiga.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  *
   6  *  Copyright (C) 1991-1998  Linus Torvalds
   7  *  Re-organised Feb 1998 Russell King
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/affs_hardblocks.h>
  12
  13 #include "check.h"
  14 #include "amiga.h"
  15
  16 static __inline__ u32
  17 checksum_block(__be32 *m, int size)
  18 {
  19         u32 sum = 0;
  20
  21         while (size--)
  22                 sum += be32_to_cpu(*m++);
  23         return sum;
  24 }
  25
  26 int
  27 amiga_partition(struct parsed_partitions *state, struct block_device *bdev)
  28 {
  29         Sector sect;
  30         unsigned char *data;
  31         struct RigidDiskBlock *rdb;
  32         struct PartitionBlock *pb;
  33         int start_sect, nr_sects, blk, part, res = 0;
  34         int blksize = 1;        /* Multiplier for disk block size */
  35         int slot = 1;
  36         char b[BDEVNAME_SIZE];
  37
  38         for (blk = 0; ; blk++, put_dev_sector(sect)) {
  39                 if (blk == RDB_ALLOCATION_LIMIT)
  40                         goto rdb_done;
  41                 data = read_dev_sector(bdev, blk, &sect);
  42                 if (!data) {
  43                         if (warn_no_part)
  44                                 printk("Dev %s: unable to read RDB block %d\n",
  45                                        bdevname(bdev, b), blk);
  46                         goto rdb_done;
  47                 }
  48                 if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
  49                         continue;
  50
  51                 rdb = (struct RigidDiskBlock *)data;
  52                 if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
  53                         break;
  54                 /* Try again with 0xdc..0xdf zeroed, Windows might have
  55                  * trashed it.
  56                  */
  57                 *(__be32 *)(data+0xdc) = 0;
  58                 if (checksum_block((__be32 *)data,
  59                                 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
  60                         printk("Warning: Trashed word at 0xd0 in block %d "
  61                                 "ignored in checksum calculation\n",blk);
  62                         break;
  63                 }
  64
  65                 printk("Dev %s: RDB in block %d has bad checksum\n",
  66                                bdevname(bdev, b), blk);
  67         }
  68
  69         /* blksize is blocks per 512 byte standard block */
  70         blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
  71
  72         printk(" RDSK (%d)", blksize * 512);    /* Be more informative */
  73         blk = be32_to_cpu(rdb->rdb_PartitionList);
  74         put_dev_sector(sect);
  75         for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
  76                 blk *= blksize; /* Read in terms partition table understands */
  77                 data = read_dev_sector(bdev, blk, &sect);
  78                 if (!data) {
  79                         if (warn_no_part)
  80                                 printk("Dev %s: unable to read partition block %d\n",
  81                                        bdevname(bdev, b), blk);
  82                         goto rdb_done;
  83                 }
  84                 pb  = (struct PartitionBlock *)data;
  85                 blk = be32_to_cpu(pb->pb_Next);
  86                 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
  87                         continue;
  88                 if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
  89                         continue;
  90
  91                 /* Tell Kernel about it */
  92
  93                 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
  94                             be32_to_cpu(pb->pb_Environment[9])) *
  95                            be32_to_cpu(pb->pb_Environment[3]) *
  96                            be32_to_cpu(pb->pb_Environment[5]) *
  97                            blksize;
  98                 if (!nr_sects)
  99                         continue;
 100                 start_sect = be32_to_cpu(pb->pb_Environment[9]) *
 101                              be32_to_cpu(pb->pb_Environment[3]) *
 102                              be32_to_cpu(pb->pb_Environment[5]) *
 103                              blksize;
 104                 put_partition(state,slot++,start_sect,nr_sects);
 105                 {
 106                         /* Be even more informative to aid mounting */
 107                         char dostype[4];
 108                         __be32 *dt = (__be32 *)dostype;
 109                         *dt = pb->pb_Environment[16];
 110                         if (dostype[3] < ' ')
 111                                 printk(" (%c%c%c^%c)",
 112                                         dostype[0], dostype[1],
 113                                         dostype[2], dostype[3] + '@' );
 114                         else
 115                                 printk(" (%c%c%c%c)",
 116                                         dostype[0], dostype[1],
 117                                         dostype[2], dostype[3]);
 118                         printk("(res %d spb %d)",
 119                                 be32_to_cpu(pb->pb_Environment[6]),
 120                                 be32_to_cpu(pb->pb_Environment[4]));
 121                 }
 122                 res = 1;
 123         }
 124         printk("\n");
 125
 126 rdb_done:
 127         return res;
 128 }