| 1 | /* $NetBSD: fat.h,v 1.9 2014/10/18 08:33:28 snj 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 pcbmap(struct denode *, u_long, daddr_t *, u_long *, int *); |
| 110 | int clusterfree(struct msdosfsmount *, u_long, u_long *); |
| 111 | int clusteralloc(struct msdosfsmount *, u_long, u_long,u_long *,u_long *); |
| 112 | int extendfile(struct denode *, u_long, struct buf **, u_long *, int); |
| 113 | int fatentry(int, struct msdosfsmount *, u_long, u_long *, u_long); |
| 114 | void fc_purge(struct denode *, u_int); |
| 115 | void fc_lookup(struct denode *, u_long, u_long *, u_long *); |
| 116 | int fillinusemap(struct msdosfsmount *); |
| 117 | int freeclusterchain(struct msdosfsmount *, u_long); |
| 118 | #endif /* _KERNEL || MAKEFS */ |
| 119 | #endif /* _MSDOSFS_FAT_H_ */ |
| 120 | |