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(u32 *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 slot = 1;
  35         char b[BDEVNAME_SIZE];
  36
  37         for (blk = 0; ; blk++, put_dev_sector(sect)) {
  38                 if (blk == RDB_ALLOCATION_LIMIT)
  39                         goto rdb_done;
  40                 data = read_dev_sector(bdev, blk, &sect);
  41                 if (!data) {
  42                         if (warn_no_part)
  43                                 printk("Dev %s: unable to read RDB block %d\n",
  44                                        bdevname(bdev, b), blk);
  45                         goto rdb_done;
  46                 }
  47                 if (*(u32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
  48                         continue;
  49
  50                 rdb = (struct RigidDiskBlock *)data;
  51                 if (checksum_block((u32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
  52                         break;
  53                 /* Try again with 0xdc..0xdf zeroed, Windows might have
  54                  * trashed it.
  55                  */
  56                 *(u32 *)(data+0xdc) = 0;
  57                 if (checksum_block((u32 *)data,
  58                                 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
  59                         printk("Warning: Trashed word at 0xd0 in block %d "
  60                                 "ignored in checksum calculation\n",blk);
  61                         break;
  62                 }
  63
  64                 printk("Dev %s: RDB in block %d has bad checksum\n",
  65                                bdevname(bdev, b), blk);
  66         }
  67
  68         printk(" RDSK");
  69         blk = be32_to_cpu(rdb->rdb_PartitionList);
  70         put_dev_sector(sect);
  71         for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
  72                 data = read_dev_sector(bdev, blk, &sect);
  73                 if (!data) {
  74                         if (warn_no_part)
  75                                 printk("Dev %s: unable to read partition block %d\n",
  76                                        bdevname(bdev, b), blk);
  77                         goto rdb_done;
  78                 }
  79                 pb  = (struct PartitionBlock *)data;
  80                 blk = be32_to_cpu(pb->pb_Next);
  81                 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
  82                         continue;
  83                 if (checksum_block((u32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
  84                         continue;
  85
  86                 /* Tell Kernel about it */
  87
  88                 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
  89                             be32_to_cpu(pb->pb_Environment[9])) *
  90                            be32_to_cpu(pb->pb_Environment[3]) *
  91                            be32_to_cpu(pb->pb_Environment[5]);
  92                 if (!nr_sects)
  93                         continue;
  94                 start_sect = be32_to_cpu(pb->pb_Environment[9]) *
  95                              be32_to_cpu(pb->pb_Environment[3]) *
  96                              be32_to_cpu(pb->pb_Environment[5]);
  97                 put_partition(state,slot++,start_sect,nr_sects);
  98                 res = 1;
  99         }
 100         printk("\n");
 101
 102 rdb_done:
 103         return res;
 104 }