1/*	$OpenBSD: fat.h,v 1.1 2016/10/18 17:05:30 natano Exp $	*/
2/*	$NetBSD: fat.h,v 1.9 2014/10/18 08:33:28 snj Exp $	*/
3
4/*-
5 * Copyright (C) 1994, 1997 Wolfgang Solfrank.
6 * Copyright (C) 1994, 1997 TooLs GmbH.
7 * All rights reserved.
8 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by TooLs GmbH.
21 * 4. The name of TooLs GmbH may not be used to endorse or promote products
22 *    derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35/*
36 * Written by Paul Popelka (paulp@uts.amdahl.com)
37 *
38 * You can do anything you want with this software, just don't say you wrote
39 * it, and don't remove this notice.
40 *
41 * This software is provided "as is".
42 *
43 * The author supplies this software to be publicly redistributed on the
44 * understanding that the author is not responsible for the correct
45 * functioning of this software in any circumstances and is not liable for
46 * any damages caused by this software.
47 *
48 * October 1992
49 */
50
51#ifndef _MSDOSFS_FAT_H_
52#define _MSDOSFS_FAT_H_
53/*
54 * Some useful cluster numbers.
55 */
56#define	MSDOSFSROOT	0		/* cluster 0 means the root dir */
57#define	CLUST_FREE	0		/* cluster 0 also means a free cluster */
58#define	MSDOSFSFREE	CLUST_FREE
59#define	CLUST_FIRST	2		/* first legal cluster number */
60#define	CLUST_RSRVD	0xfffffff6	/* reserved cluster range */
61#define	CLUST_BAD	0xfffffff7	/* a cluster with a defect */
62#define	CLUST_EOFS	0xfffffff8	/* start of eof cluster range */
63#define	CLUST_EOFE	0xffffffff	/* end of eof cluster range */
64#define	CLUST_END	CLUST_EOFE	/* bigger than any valid cluster */
65
66#define	FAT12_MASK	0x00000fff	/* mask for 12 bit cluster numbers */
67#define	FAT16_MASK	0x0000ffff	/* mask for 16 bit cluster numbers */
68#define	FAT32_MASK	0x0fffffff	/* mask for FAT32 cluster numbers */
69
70/*
71 * MSDOSFS:
72 * Return true if filesystem uses 12 bit FATs. Microsoft Programmer's
73 * Reference says if the maximum cluster number in a filesystem is greater
74 * than 4084 ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK) then we've got a
75 * 16 bit FAT filesystem. While mounting, the result of this test is stored
76 * in pm_fatentrysize.
77 */
78#define	FAT12(pmp)	(pmp->pm_fatmask == FAT12_MASK)
79#define	FAT16(pmp)	(pmp->pm_fatmask == FAT16_MASK)
80#define	FAT32(pmp)	(pmp->pm_fatmask == FAT32_MASK)
81
82/*
83 * M$ in its unlimited wisdom decided that EOF mark is anything
84 * between 0xfffffff8 and 0xffffffff (masked by appropriate fatmask,
85 * of course).
86 * Note that cn is supposed to be already adjusted accordingly to FAT type.
87 */
88#define	MSDOSFSEOF(cn, fatmask)	\
89	(((cn) & CLUST_EOFS) == (CLUST_EOFS & (fatmask)))
90
91/*
92 * These are the values for the function argument to the function
93 * fatentry().
94 */
95#define	FAT_GET		0x0001	/* get a FAT entry */
96#define	FAT_SET		0x0002	/* set a FAT entry */
97#define	FAT_GET_AND_SET	(FAT_GET | FAT_SET)
98
99/*
100 * Flags to extendfile:
101 */
102#define	DE_CLEAR	1	/* Zero out the blocks allocated */
103
104int pcbmap(struct denode *, u_long, daddr_t *, u_long *, int *);
105int clusterfree(struct msdosfsmount *, u_long, u_long *);
106int clusteralloc(struct msdosfsmount *, u_long, u_long,u_long *,u_long *);
107int extendfile(struct denode *, u_long, struct mkfsbuf **, u_long *, int);
108int fatentry(int, struct msdosfsmount *, u_long, u_long *, u_long);
109void fc_purge(struct denode *, u_int);
110void fc_lookup(struct denode *, u_long, u_long *, u_long *);
111int fillinusemap(struct msdosfsmount *);
112int freeclusterchain(struct msdosfsmount *, u_long);
113#endif /* _MSDOSFS_FAT_H_ */
114