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                         res = -1;
  47                         goto rdb_done;
  48                 }
  49                 if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
  50                         continue;
  51
  52                 rdb = (struct RigidDiskBlock *)data;
  53                 if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
  54                         break;
  55                 /* Try again with 0xdc..0xdf zeroed, Windows might have
  56                  * trashed it.
  57                  */
  58                 *(__be32 *)(data+0xdc) = 0;
  59                 if (checksum_block((__be32 *)data,
  60                                 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
  61                         printk("Warning: Trashed word at 0xd0 in block %d "
  62                                 "ignored in checksum calculation\n",blk);
  63                         break;
  64                 }
  65
  66                 printk("Dev %s: RDB in block %d has bad checksum\n",
  67                                bdevname(bdev, b), blk);
  68         }
  69
  70         /* blksize is blocks per 512 byte standard block */
  71         blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
  72
  73         printk(" RDSK (%d)", blksize * 512);    /* Be more informative */
  74         blk = be32_to_cpu(rdb->rdb_PartitionList);
  75         put_dev_sector(sect);
  76         for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
  77                 blk *= blksize; /* Read in terms partition table understands */
  78                 data = read_dev_sector(bdev, blk, &sect);
  79                 if (!data) {
  80                         if (warn_no_part)
  81                                 printk("Dev %s: unable to read partition block %d\n",
  82                                        bdevname(bdev, b), blk);
  83                         res = -1;
  84                         goto rdb_done;
  85                 }
  86                 pb  = (struct PartitionBlock *)data;
  87                 blk = be32_to_cpu(pb->pb_Next);
  88                 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
  89                         continue;
  90                 if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
  91                         continue;
  92
  93                 /* Tell Kernel about it */
  94
  95                 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
  96                             be32_to_cpu(pb->pb_Environment[9])) *
  97                            be32_to_cpu(pb->pb_Environment[3]) *
  98                            be32_to_cpu(pb->pb_Environment[5]) *
  99                            blksize;
 100                 if (!nr_sects)
 101                         continue;
 102                 start_sect = be32_to_cpu(pb->pb_Environment[9]) *
 103                              be32_to_cpu(pb->pb_Environment[3]) *
 104                              be32_to_cpu(pb->pb_Environment[5]) *
 105                              blksize;
 106                 put_partition(state,slot++,start_sect,nr_sects);
 107                 {
 108                         /* Be even more informative to aid mounting */
 109                         char dostype[4];
 110                         __be32 *dt = (__be32 *)dostype;
 111                         *dt = pb->pb_Environment[16];
 112                         if (dostype[3] < ' ')
 113                                 printk(" (%c%c%c^%c)",
 114                                         dostype[0], dostype[1],
 115                                         dostype[2], dostype[3] + '@' );
 116                         else
 117                                 printk(" (%c%c%c%c)",
 118                                         dostype[0], dostype[1],
 119                                         dostype[2], dostype[3]);
 120                         printk("(res %d spb %d)",
 121                                 be32_to_cpu(pb->pb_Environment[6]),
 122                                 be32_to_cpu(pb->pb_Environment[4]));
 123                 }
 124                 res = 1;
 125         }
 126         printk("\n");
 127
 128 rdb_done:
 129         return res;
 130 }