LXR linux-bk/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
  16static __inline__ u32
  17checksum_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
  26int
  27amiga_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
 126rdb_done:
 127        return res;
 128}
 129