/*      $NetBSD: floppy_2hc.c,v 1.5 2009/02/04 15:22:13 tsutsui Exp $   */

/*-
 * Copyright (c) 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/types.h>
#include "common.h"

bool
blk_to_2hc_position(uint32_t logical_block_number, uint32_t *position,
    int *count)
{
        int sector, side, cylinder;

        /*
         * 2HC: MFM format
         *      80 cylinders/disk
         *       2 sides/disk
         *      15 sectors/track
         *     512 bytes/sector
         */
        if (logical_block_number >= 2400)
                return false;

        cylinder = logical_block_number / (15 * 2);
        side = logical_block_number - (cylinder * 15 * 2) > 14;
        sector = logical_block_number - (side + cylinder * 2) * 15;

        if (position)
                *position = (cylinder << 16) | (side << 8) | (sector + 1);
        if (count)
                *count = 15 - sector;

        return true;
}