amiga.c

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/*
 *  fs/partitions/amiga.c
 *
 *  Code extracted from drivers/block/genhd.c
 *
 *  Copyright (C) 1991-1998  Linus Torvalds
 *  Re-organised Feb 1998 Russell King
 */

#include <linux/types.h>
#include <linux/affs_hardblocks.h>

#include "check.h"
#include "amiga.h"

static __inline__ u32
checksum_block(__be32 *m, int size)
{
    u32 sum = 0;

    while (size--)
        sum += be32_to_cpu(*m++);
    return sum;
}

int amiga_partition(struct parsed_partitions *state)
{
    Sector sect;
    unsigned char *data;
    struct RigidDiskBlock *rdb;
    struct PartitionBlock *pb;
    int start_sect, nr_sects, blk, part, res = 0;
    int blksize = 1;    /* Multiplier for disk block size */
    int slot = 1;
    char b[BDEVNAME_SIZE];

    for (blk = 0; ; blk++, put_dev_sector(sect)) {
        if (blk == RDB_ALLOCATION_LIMIT)
            goto rdb_done;
        data = read_part_sector(state, blk, &sect);
        if (!data) {
            if (warn_no_part)
                printk("Dev %s: unable to read RDB block %d\n",
                       bdevname(state->bdev, b), blk);
            res = -1;
            goto rdb_done;
        }
        if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
            continue;

        rdb = (struct RigidDiskBlock *)data;
        if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
            break;
        /* Try again with 0xdc..0xdf zeroed, Windows might have
         * trashed it.
         */
        *(__be32 *)(data+0xdc) = 0;
        if (checksum_block((__be32 *)data,
                be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
            printk("Warning: Trashed word at 0xd0 in block %d "
                "ignored in checksum calculation\n",blk);
            break;
        }

        printk("Dev %s: RDB in block %d has bad checksum\n",
               bdevname(state->bdev, b), blk);
    }

    /* blksize is blocks per 512 byte standard block */
    blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;

    {
        char tmp[7 + 10 + 1 + 1];

        /* Be more informative */
        snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512);
        strlcat(state->pp_buf, tmp, PAGE_SIZE);
    }
    blk = be32_to_cpu(rdb->rdb_PartitionList);
    put_dev_sector(sect);
    for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
        blk *= blksize; /* Read in terms partition table understands */
        data = read_part_sector(state, blk, &sect);
        if (!data) {
            if (warn_no_part)
                printk("Dev %s: unable to read partition block %d\n",
                       bdevname(state->bdev, b), blk);
            res = -1;
            goto rdb_done;
        }
        pb  = (struct PartitionBlock *)data;
        blk = be32_to_cpu(pb->pb_Next);
        if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
            continue;
        if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
            continue;

        /* Tell Kernel about it */

        nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
                be32_to_cpu(pb->pb_Environment[9])) *
               be32_to_cpu(pb->pb_Environment[3]) *
               be32_to_cpu(pb->pb_Environment[5]) *
               blksize;
        if (!nr_sects)
            continue;
        start_sect = be32_to_cpu(pb->pb_Environment[9]) *
                 be32_to_cpu(pb->pb_Environment[3]) *
                 be32_to_cpu(pb->pb_Environment[5]) *
                 blksize;
        put_partition(state,slot++,start_sect,nr_sects);
        {
            /* Be even more informative to aid mounting */
            char dostype[4];
            char tmp[42];

            __be32 *dt = (__be32 *)dostype;
            *dt = pb->pb_Environment[16];
            if (dostype[3] < ' ')
                snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)",
                    dostype[0], dostype[1],
                    dostype[2], dostype[3] + '@' );
            else
                snprintf(tmp, sizeof(tmp), " (%c%c%c%c)",
                    dostype[0], dostype[1],
                    dostype[2], dostype[3]);
            strlcat(state->pp_buf, tmp, PAGE_SIZE);
            snprintf(tmp, sizeof(tmp), "(res %d spb %d)",
                be32_to_cpu(pb->pb_Environment[6]),
                be32_to_cpu(pb->pb_Environment[4]));
            strlcat(state->pp_buf, tmp, PAGE_SIZE);
        }
        res = 1;
    }
    strlcat(state->pp_buf, "\n", PAGE_SIZE);

rdb_done:
    return res;
}