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 */ 108 109 int msdosfs_pcbmap(struct denode *, u_long, daddr_t *, u_long *, int *); 110 int msdosfs_clusterfree(struct msdosfsmount *, u_long, u_long *); 111 int msdosfs_clusteralloc(struct msdosfsmount *, u_long, u_long, u_long *, 112 u_long *); 113 int msdosfs_extendfile(struct denode *, u_long, struct buf **, u_long *, 114 int); 115 int msdosfs_fatentry(int, struct msdosfsmount *, u_long, u_long *, u_long); 116 void msdosfs_fc_purge(struct denode *, u_int); 117 void msdosfs_fc_lookup(struct denode *, u_long, u_long *, u_long *); 118 int msdosfs_fillinusemap(struct msdosfsmount *); 119 int msdosfs_freeclusterchain(struct msdosfsmount *, u_long); 120 #endif /* _KERNEL || MAKEFS */ 121 #endif /* _MSDOSFS_FAT_H_ */ 122