LXR linux/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                        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
 128rdb_done:
 129        return res;
 130}
 131