1/*	$NetBSD: fat.h,v 1.10 2021/10/23 16:58:17 thorpej Exp $	*/
  2
  3/*-
  4 * Copyright (C) 1994, 1997 Wolfgang Solfrank.
  5 * Copyright (C) 1994, 1997 TooLs GmbH.
  6 * All rights reserved.
  7 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
  8 *
  9 * Redistribution and use in source and binary forms, with or without
 10 * modification, are permitted provided that the following conditions
 11 * are met:
 12 * 1. Redistributions of source code must retain the above copyright
 13 *    notice, this list of conditions and the following disclaimer.
 14 * 2. Redistributions in binary form must reproduce the above copyright
 15 *    notice, this list of conditions and the following disclaimer in the
 16 *    documentation and/or other materials provided with the distribution.
 17 * 3. All advertising materials mentioning features or use of this software
 18 *    must display the following acknowledgement:
 19 *	This product includes software developed by TooLs GmbH.
 20 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 21 *    derived from this software without specific prior written permission.
 22 *
 23 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 26 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 33 */
 34/*
 35 * Written by Paul Popelka (paulp@uts.amdahl.com)
 36 *
 37 * You can do anything you want with this software, just don't say you wrote
 38 * it, and don't remove this notice.
 39 *
 40 * This software is provided "as is".
 41 *
 42 * The author supplies this software to be publicly redistributed on the
 43 * understanding that the author is not responsible for the correct
 44 * functioning of this software in any circumstances and is not liable for
 45 * any damages caused by this software.
 46 *
 47 * October 1992
 48 */
 49
 50#ifndef _MSDOSFS_FAT_H_
 51#define _MSDOSFS_FAT_H_
 52/*
 53 * Some useful cluster numbers.
 54 */
 55#define	MSDOSFSROOT	0		/* cluster 0 means the root dir */
 56#define	CLUST_FREE	0		/* cluster 0 also means a free cluster */
 57#define	MSDOSFSFREE	CLUST_FREE
 58#define	CLUST_FIRST	2		/* first legal cluster number */
 59#define	CLUST_RSRVD	0xfffffff6	/* reserved cluster range */
 60#define	CLUST_BAD	0xfffffff7	/* a cluster with a defect */
 61#define	CLUST_EOFS	0xfffffff8	/* start of eof cluster range */
 62#define	CLUST_EOFE	0xffffffff	/* end of eof cluster range */
 63#define	CLUST_END	CLUST_EOFE	/* bigger than any valid cluster */
 64
 65#define	FAT12_MASK	0x00000fff	/* mask for 12 bit cluster numbers */
 66#define	FAT16_MASK	0x0000ffff	/* mask for 16 bit cluster numbers */
 67#define	FAT32_MASK	0x0fffffff	/* mask for FAT32 cluster numbers */
 68
 69/*
 70 * MSDOSFS:
 71 * Return true if filesystem uses 12 bit FATs. Microsoft Programmer's
 72 * Reference says if the maximum cluster number in a filesystem is greater
 73 * than 4084 ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK) then we've got a
 74 * 16 bit FAT filesystem. While mounting, the result of this test is stored
 75 * in pm_fatentrysize.
 76 * GEMDOS-flavour (atari):
 77 * If the filesystem is on floppy we've got a 12 bit FAT filesystem, otherwise
 78 * 16 bit. We check the d_type field in the disklabel struct while mounting
 79 * and store the result in the pm_fatentrysize. Note that this kind of
 80 * detection gets flakey when mounting a vnd-device.
 81 */
 82#define	FAT12(pmp)	(pmp->pm_fatmask == FAT12_MASK)
 83#define	FAT16(pmp)	(pmp->pm_fatmask == FAT16_MASK)
 84#define	FAT32(pmp)	(pmp->pm_fatmask == FAT32_MASK)
 85
 86/*
 87 * M$ in its unlimited wisdom decided that EOF mark is anything
 88 * between 0xfffffff8 and 0xffffffff (masked by appropriate fatmask,
 89 * of course).
 90 * Note that cn is supposed to be already adjusted accordingly to FAT type.
 91 */
 92#define	MSDOSFSEOF(cn, fatmask)	\
 93	(((cn) & CLUST_EOFS) == (CLUST_EOFS & (fatmask)))
 94
 95#if defined(_KERNEL) || defined(MAKEFS)
 96/*
 97 * These are the values for the function argument to the function
 98 * fatentry().
 99 */
100#define	FAT_GET		0x0001	/* get a FAT entry */
101#define	FAT_SET		0x0002	/* set a FAT entry */
102#define	FAT_GET_AND_SET	(FAT_GET | FAT_SET)
103
104/*
105 * Flags to extendfile:
106 */
107#define	DE_CLEAR	1	/* Zero out the blocks allocated */
108
109int	msdosfs_pcbmap(struct denode *, u_long, daddr_t *, u_long *, int *);
110int	msdosfs_clusterfree(struct msdosfsmount *, u_long, u_long *);
111int	msdosfs_clusteralloc(struct msdosfsmount *, u_long, u_long, u_long *,
112	    u_long *);
113int	msdosfs_extendfile(struct denode *, u_long, struct buf **, u_long *,
114	    int);
115int	msdosfs_fatentry(int, struct msdosfsmount *, u_long, u_long *, u_long);
116void	msdosfs_fc_purge(struct denode *, u_int);
117void	msdosfs_fc_lookup(struct denode *, u_long, u_long *, u_long *);
118int	msdosfs_fillinusemap(struct msdosfsmount *);
119int	msdosfs_freeclusterchain(struct msdosfsmount *, u_long);
120#endif /* _KERNEL || MAKEFS */
121#endif /* _MSDOSFS_FAT_H_ */