xref: /freebsd/usr.sbin/fstyp/msdosfs.h (revision 6b7b2d80ed4d728d3ffd12c422e57798c1b63a84)
1 /*-
2  * Copyright (c) 2006 Tobias Reifenberger
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/types.h>
30 
31 /*
32  * Conversion macros for little endian encoded unsigned integers
33  * in byte streams to the local unsigned integer format.
34  */
35 #define UINT16BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1])))
36 #define UINT32BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1]) +		\
37 	    (65536*(p)[2]) + (16777216*(p)[3])))
38 
39 /*
40  * All following structures are according to:
41  *
42  * Microsoft Extensible Firmware Initiative FAT32 File System Specification
43  * FAT: General Overview of On-Disk Format
44  * Version 1.03, December 6, 2000
45  * Microsoft Corporation
46  */
47 
48 /*
49  * FAT boot sector and boot parameter block for
50  * FAT12 and FAT16 volumes
51  */
52 typedef struct fat_bsbpb {
53 	/* common fields */
54 	uint8_t BS_jmpBoot[3];
55 	uint8_t BS_OEMName[8];
56 	uint8_t BPB_BytsPerSec[2];
57 	uint8_t BPB_SecPerClus;
58 	uint8_t BPB_RsvdSecCnt[2];
59 	uint8_t BPB_NumFATs;
60 	uint8_t BPB_RootEntCnt[2];
61 	uint8_t BPB_TotSec16[2];
62 	uint8_t BPB_Media;
63 	uint8_t BPB_FATSz16[2];
64 	uint8_t BPB_SecPerTrack[2];
65 	uint8_t BPB_NumHeads[2];
66 	uint8_t BPB_HiddSec[4];
67 	uint8_t BPB_TotSec32[4];
68 	/* FAT12/FAT16 only fields */
69 	uint8_t BS_DrvNum;
70 	uint8_t BS_Reserved1;
71 	uint8_t BS_BootSig;
72 	uint8_t BS_VolID[4];
73 	uint8_t BS_VolLab[11];
74 	uint8_t BS_FilSysType[8];
75 } FAT_BSBPB; /* 62 bytes */
76 
77 /*
78  * FAT boot sector and boot parameter block for
79  * FAT32 volumes
80  */
81 typedef struct fat32_bsbpb {
82 	/* common fields */
83 	uint8_t BS_jmpBoot[3];
84 	uint8_t BS_OEMName[8];
85 	uint8_t BPB_BytsPerSec[2];
86 	uint8_t BPB_SecPerClus;
87 	uint8_t BPB_RsvdSecCnt[2];
88 	uint8_t BPB_NumFATs;
89 	uint8_t BPB_RootEntCnt[2];
90 	uint8_t BPB_TotSec16[2];
91 	uint8_t BPB_Media;
92 	uint8_t BPB_FATSz16[2];
93 	uint8_t BPB_SecPerTrack[2];
94 	uint8_t BPB_NumHeads[2];
95 	uint8_t BPB_HiddSec[4];
96 	uint8_t BPB_TotSec32[4];
97 	/* FAT32 only fields */
98 	uint8_t BPB_FATSz32[4];
99 	uint8_t BPB_ExtFlags[2];
100 	uint8_t BPB_FSVer[2];
101 	uint8_t BPB_RootClus[4];
102 	uint8_t BPB_FSInfo[2];
103 	uint8_t BPB_BkBootSec[2];
104 	uint8_t BPB_Reserved[12];
105 	uint8_t BS_DrvNum;
106 	uint8_t BS_Reserved1;
107 	uint8_t BS_BootSig;
108 	uint8_t BS_VolID[4];
109 	uint8_t BS_VolLab[11];
110 	uint8_t BS_FilSysType[8];
111 } FAT32_BSBPB; /* 90 bytes */
112 
113 /*
114  * FAT directory entry structure
115  */
116 #define	FAT_DES_ATTR_READ_ONLY	0x01
117 #define	FAT_DES_ATTR_HIDDEN	0x02
118 #define	FAT_DES_ATTR_SYSTEM	0x04
119 #define	FAT_DES_ATTR_VOLUME_ID	0x08
120 #define	FAT_DES_ATTR_DIRECTORY	0x10
121 #define	FAT_DES_ATTR_ARCHIVE	0x20
122 #define	FAT_DES_ATTR_LONG_NAME	(FAT_DES_ATTR_READ_ONLY |		\
123 				 FAT_DES_ATTR_HIDDEN |			\
124 				 FAT_DES_ATTR_SYSTEM |			\
125 				 FAT_DES_ATTR_VOLUME_ID)
126 
127 typedef struct fat_des {
128 	uint8_t DIR_Name[11];
129 	uint8_t DIR_Attr;
130 	uint8_t DIR_NTRes;
131 	uint8_t DIR_CrtTimeTenth;
132 	uint8_t DIR_CrtTime[2];
133 	uint8_t DIR_CrtDate[2];
134 	uint8_t DIR_LstAccDate[2];
135 	uint8_t DIR_FstClusHI[2];
136 	uint8_t DIR_WrtTime[2];
137 	uint8_t DIR_WrtDate[2];
138 	uint8_t DIR_FstClusLO[2];
139 	uint8_t DIR_FileSize[4];
140 } FAT_DES;
141