xref: /dragonfly/usr.sbin/fstyp/msdosfs.h (revision 551c4c36)
1 /*-
2  * Copyright (c) 2016 The DragonFly Project
3  * Copyright (c) 2006 Tobias Reifenberger
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include <sys/types.h>
31 
32 /*
33  * Conversion macros for little endian encoded unsigned integers
34  * in byte streams to the local unsigned integer format.
35  */
36 #define UINT16BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1])))
37 #define UINT32BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1]) +		\
38 	    (65536*(p)[2]) + (16777216*(p)[3])))
39 
40 /*
41  * All following structures are according to:
42  *
43  * Microsoft Extensible Firmware Initiative FAT32 File System Specification
44  * FAT: General Overview of On-Disk Format
45  * Version 1.03, December 6, 2000
46  * Microsoft Corporation
47  */
48 
49 /*
50  * FAT boot sector and boot parameter block for
51  * FAT12 and FAT16 volumes
52  */
53 typedef struct fat_bsbpb {
54 	/* common fields */
55 	uint8_t BS_jmpBoot[3];
56 	uint8_t BS_OEMName[8];
57 	uint8_t BPB_BytsPerSec[2];
58 	uint8_t BPB_SecPerClus;
59 	uint8_t BPB_RsvdSecCnt[2];
60 	uint8_t BPB_NumFATs;
61 	uint8_t BPB_RootEntCnt[2];
62 	uint8_t BPB_TotSec16[2];
63 	uint8_t BPB_Media;
64 	uint8_t BPB_FATSz16[2];
65 	uint8_t BPB_SecPerTrack[2];
66 	uint8_t BPB_NumHeads[2];
67 	uint8_t BPB_HiddSec[4];
68 	uint8_t BPB_TotSec32[4];
69 	/* FAT12/FAT16 only fields */
70 	uint8_t BS_DrvNum;
71 	uint8_t BS_Reserved1;
72 	uint8_t BS_BootSig;
73 	uint8_t BS_VolID[4];
74 	uint8_t BS_VolLab[11];
75 	uint8_t BS_FilSysType[8];
76 } FAT_BSBPB; /* 62 bytes */
77 
78 /*
79  * FAT boot sector and boot parameter block for
80  * FAT32 volumes
81  */
82 typedef struct fat32_bsbpb {
83 	/* common fields */
84 	uint8_t BS_jmpBoot[3];
85 	uint8_t BS_OEMName[8];
86 	uint8_t BPB_BytsPerSec[2];
87 	uint8_t BPB_SecPerClus;
88 	uint8_t BPB_RsvdSecCnt[2];
89 	uint8_t BPB_NumFATs;
90 	uint8_t BPB_RootEntCnt[2];
91 	uint8_t BPB_TotSec16[2];
92 	uint8_t BPB_Media;
93 	uint8_t BPB_FATSz16[2];
94 	uint8_t BPB_SecPerTrack[2];
95 	uint8_t BPB_NumHeads[2];
96 	uint8_t BPB_HiddSec[4];
97 	uint8_t BPB_TotSec32[4];
98 	/* FAT32 only fields */
99 	uint8_t BPB_FATSz32[4];
100 	uint8_t BPB_ExtFlags[2];
101 	uint8_t BPB_FSVer[2];
102 	uint8_t BPB_RootClus[4];
103 	uint8_t BPB_FSInfo[2];
104 	uint8_t BPB_BkBootSec[2];
105 	uint8_t BPB_Reserved[12];
106 	uint8_t BS_DrvNum;
107 	uint8_t BS_Reserved1;
108 	uint8_t BS_BootSig;
109 	uint8_t BS_VolID[4];
110 	uint8_t BS_VolLab[11];
111 	uint8_t BS_FilSysType[8];
112 } FAT32_BSBPB; /* 90 bytes */
113 
114 /*
115  * FAT directory entry structure
116  */
117 #define	FAT_DES_ATTR_READ_ONLY	0x01
118 #define	FAT_DES_ATTR_HIDDEN	0x02
119 #define	FAT_DES_ATTR_SYSTEM	0x04
120 #define	FAT_DES_ATTR_VOLUME_ID	0x08
121 #define	FAT_DES_ATTR_DIRECTORY	0x10
122 #define	FAT_DES_ATTR_ARCHIVE	0x20
123 #define	FAT_DES_ATTR_LONG_NAME	(FAT_DES_ATTR_READ_ONLY |		\
124 				 FAT_DES_ATTR_HIDDEN |			\
125 				 FAT_DES_ATTR_SYSTEM |			\
126 				 FAT_DES_ATTR_VOLUME_ID)
127 
128 typedef struct fat_des {
129 	uint8_t DIR_Name[11];
130 	uint8_t DIR_Attr;
131 	uint8_t DIR_NTRes;
132 	uint8_t DIR_CrtTimeTenth;
133 	uint8_t DIR_CrtTime[2];
134 	uint8_t DIR_CrtDate[2];
135 	uint8_t DIR_LstAccDate[2];
136 	uint8_t DIR_FstClusHI[2];
137 	uint8_t DIR_WrtTime[2];
138 	uint8_t DIR_WrtDate[2];
139 	uint8_t DIR_FstClusLO[2];
140 	uint8_t DIR_FileSize[4];
141 } FAT_DES;
142