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      1 /*	$NetBSD: dosfs.h,v 1.8 2015/01/02 06:21:28 mlelstv Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
      5  * Copyright (c) 1995 Martin Husemann
      6  * Some structure declaration borrowed from Paul Popelka
      7  * (paulp (at) uts.amdahl.com), see sys/fs/msdosfs/ for reference.
      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  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #ifndef DOSFS_H
     31 #define DOSFS_H
     32 
     33 #define DOSBOOTBLOCKSIZE 512
     34 
     35 typedef	u_int32_t	cl_t;	/* type holding a cluster number */
     36 
     37 /*
     38  * architecture independent description of all the info stored in a
     39  * FAT boot block.
     40  */
     41 struct bootblock {
     42 	u_int	BytesPerSec;		/* bytes per sector */
     43 	u_int	SecPerClust;		/* sectors per cluster */
     44 	u_int	ResSectors;		/* number of reserved sectors */
     45 	u_int	FATs;			/* number of FATs */
     46 	u_int	RootDirEnts;		/* number of root directory entries */
     47 	u_int	Media;			/* media descriptor */
     48 	u_int	FATsmall;		/* number of sectors per FAT */
     49 	u_int	SecPerTrack;		/* sectors per track */
     50 	u_int	Heads;			/* number of heads */
     51 	u_int32_t Sectors;		/* total number of sectors */
     52 	u_int32_t HiddenSecs;		/* # of hidden sectors */
     53 	u_int32_t HugeSectors;		/* # of sectors if bpbSectors == 0 */
     54 	u_int	FSInfo;			/* FSInfo sector */
     55 	u_int	Backup;			/* Backup of Bootblocks */
     56 	cl_t	RootCl;			/* Start of Root Directory */
     57 	cl_t	FSFree;			/* Number of free clusters acc. FSInfo */
     58 	cl_t	FSNext;			/* Next free cluster acc. FSInfo */
     59 
     60 	/* and some more calculated values */
     61 	u_int	flags;			/* some flags: */
     62 #define	FAT32		1		/* this is a FAT32 filesystem */
     63 					/*
     64 					 * Maybe, we should separate out
     65 					 * various parts of FAT32?	XXX
     66 					 */
     67 	int	ValidFat;		/* valid fat if FAT32 non-mirrored */
     68 	cl_t	ClustMask;		/* mask for entries in FAT */
     69 	cl_t	NumClusters;		/* # of entries in a FAT */
     70 	u_int32_t NumSectors;		/* how many sectors are there */
     71 	u_int32_t FATsecs;		/* how many sectors are in FAT */
     72 	u_int32_t NumFatEntries;	/* how many entries really are there */
     73 	u_int	FirstCluster;		/* at what sector is Cluster CLUST_FIRST */
     74 	u_int	ClusterSize;		/* Cluster size in bytes */
     75 
     76 	/* Now some statistics: */
     77 	u_int	NumFiles;		/* # of plain files */
     78 	u_int	NumFree;		/* # of free clusters */
     79 	u_int	NumBad;			/* # of bad clusters */
     80 };
     81 
     82 struct fatEntry {
     83 	cl_t	next;			/* pointer to next cluster */
     84 	cl_t	head;			/* pointer to start of chain */
     85 	u_int32_t length;		/* number of clusters on chain */
     86 	int	flags;			/* see below */
     87 };
     88 
     89 #define	CLUST_FREE	0		/* 0 means cluster is free */
     90 #define	CLUST_FIRST	2		/* 2 is the minimum valid cluster number */
     91 #define	CLUST_RSRVD	0xfffffff6	/* start of reserved clusters */
     92 #define	CLUST_BAD	0xfffffff7	/* a cluster with a defect */
     93 #define	CLUST_EOFS	0xfffffff8	/* start of EOF indicators */
     94 #define	CLUST_EOF	0xffffffff	/* standard value for last cluster */
     95 
     96 /*
     97  * Masks for cluster values
     98  */
     99 #define	CLUST12_MASK	0xfff
    100 #define	CLUST16_MASK	0xffff
    101 #define	CLUST32_MASK	0xfffffff
    102 
    103 #define	FAT_USED	1		/* This fat chain is used in a file */
    104 
    105 #define	DOSLONGNAMELEN	256		/* long name maximal length */
    106 #define LRFIRST		0x40		/* first long name record */
    107 #define	LRNOMASK	0x1f		/* mask to extract long record
    108 					 * sequence number */
    109 
    110 /*
    111  * Architecture independent description of a directory entry
    112  */
    113 struct dosDirEntry {
    114 	struct dosDirEntry
    115 		*parent,		/* previous tree level */
    116 		*next,			/* next brother */
    117 		*child;			/* if this is a directory */
    118 	char name[8+1+3+1];		/* alias name first part */
    119 	char lname[DOSLONGNAMELEN];	/* real name */
    120 	uint flags;			/* attributes */
    121 	cl_t head;			/* cluster no */
    122 	u_int32_t size;			/* filesize in bytes */
    123 	uint fsckflags;			/* flags during fsck */
    124 };
    125 /* Flags in fsckflags: */
    126 #define	DIREMPTY	1
    127 #define	DIREMPWARN	2
    128 
    129 /*
    130  *  TODO-list of unread directories
    131  */
    132 struct dirTodoNode {
    133 	struct dosDirEntry *dir;
    134 	struct dirTodoNode *next;
    135 };
    136 
    137 #endif
    138