floppy_2d.c revision 1.1.18.2
1 1.1.18.2 yamt /* $NetBSD: floppy_2d.c,v 1.1.18.2 2006/06/21 14:51:21 yamt Exp $ */ 2 1.1.18.2 yamt 3 1.1.18.2 yamt /*- 4 1.1.18.2 yamt * Copyright (c) 2004 The NetBSD Foundation, Inc. 5 1.1.18.2 yamt * All rights reserved. 6 1.1.18.2 yamt * 7 1.1.18.2 yamt * This code is derived from software contributed to The NetBSD Foundation 8 1.1.18.2 yamt * by UCHIYAMA Yasushi. 9 1.1.18.2 yamt * 10 1.1.18.2 yamt * Redistribution and use in source and binary forms, with or without 11 1.1.18.2 yamt * modification, are permitted provided that the following conditions 12 1.1.18.2 yamt * are met: 13 1.1.18.2 yamt * 1. Redistributions of source code must retain the above copyright 14 1.1.18.2 yamt * notice, this list of conditions and the following disclaimer. 15 1.1.18.2 yamt * 2. Redistributions in binary form must reproduce the above copyright 16 1.1.18.2 yamt * notice, this list of conditions and the following disclaimer in the 17 1.1.18.2 yamt * documentation and/or other materials provided with the distribution. 18 1.1.18.2 yamt * 3. All advertising materials mentioning features or use of this software 19 1.1.18.2 yamt * must display the following acknowledgement: 20 1.1.18.2 yamt * This product includes software developed by the NetBSD 21 1.1.18.2 yamt * Foundation, Inc. and its contributors. 22 1.1.18.2 yamt * 4. Neither the name of The NetBSD Foundation nor the names of its 23 1.1.18.2 yamt * contributors may be used to endorse or promote products derived 24 1.1.18.2 yamt * from this software without specific prior written permission. 25 1.1.18.2 yamt * 26 1.1.18.2 yamt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 1.1.18.2 yamt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 1.1.18.2 yamt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 1.1.18.2 yamt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 1.1.18.2 yamt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 1.1.18.2 yamt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 1.1.18.2 yamt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 1.1.18.2 yamt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 1.1.18.2 yamt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 1.1.18.2 yamt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 1.1.18.2 yamt * POSSIBILITY OF SUCH DAMAGE. 37 1.1.18.2 yamt */ 38 1.1.18.2 yamt 39 1.1.18.2 yamt #include <sys/types.h> 40 1.1.18.2 yamt #include "common.h" 41 1.1.18.2 yamt 42 1.1.18.2 yamt boolean_t 43 1.1.18.2 yamt blk_to_2d_position(uint32_t logical_block_number, uint32_t *position, 44 1.1.18.2 yamt int *count) 45 1.1.18.2 yamt { 46 1.1.18.2 yamt int i, sector, side, cylinder; 47 1.1.18.2 yamt 48 1.1.18.2 yamt /* 49 1.1.18.2 yamt * 2D: MFM format (cylinder 0 side 0 is FM format) 50 1.1.18.2 yamt * 77 cylinders/disk 51 1.1.18.2 yamt * 2 sides/disk 52 1.1.18.2 yamt * 26 sectors/track 53 1.1.18.2 yamt * 256 bytes/sector (cylinder 0 side 0 is 128 bytes/sector) 54 1.1.18.2 yamt * 55 1.1.18.2 yamt * 0-1988 : MFM 56 1.1.18.2 yamt * 1989-1995 : FM 57 1.1.18.2 yamt */ 58 1.1.18.2 yamt if (logical_block_number > 1988) 59 1.1.18.2 yamt return FALSE; /* don't support FM track */ 60 1.1.18.2 yamt 61 1.1.18.2 yamt i = logical_block_number * 2 + 26; 62 1.1.18.2 yamt cylinder = i / (26 * 2); 63 1.1.18.2 yamt side = i - (cylinder * 26 * 2) > 25; 64 1.1.18.2 yamt sector = i - (side + cylinder * 2) * 26 + 1; 65 1.1.18.2 yamt if (position) 66 1.1.18.2 yamt *position = (cylinder << 16) | (side << 8) | sector; 67 1.1.18.2 yamt if (count) 68 1.1.18.2 yamt *count = 2; 69 1.1.18.2 yamt 70 1.1.18.2 yamt return TRUE; 71 1.1.18.2 yamt } 72 1.1.18.2 yamt 73
Indexes created Mon Oct 20 20:10:13 GMT 2025