xref: /freebsd/sys/geom/label/g_label_msdosfs.h (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2006 Tobias Reifenberger
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/types.h>
32 
33 /*
34  * Conversion macros for little endian encoded unsigned integers
35  * in byte streams to the local unsigned integer format.
36  */
37 #define UINT16BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1])))
38 #define UINT32BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1]) +		\
39 	    (65536*(p)[2]) + (16777216*(p)[3])))
40 
41 /*
42  * All following structures are according to:
43  *
44  * Microsoft Extensible Firmware Initiative FAT32 File System Specification
45  * FAT: General Overview of On-Disk Format
46  * Version 1.03, December 6, 2000
47  * Microsoft Corporation
48  */
49 
50 /*
51  * FAT boot sector and boot parameter block for
52  * FAT12 and FAT16 volumes
53  */
54 typedef struct fat_bsbpb {
55 	/* common fields */
56 	uint8_t BS_jmpBoot[3];
57 	uint8_t BS_OEMName[8];
58 	uint8_t BPB_BytsPerSec[2];
59 	uint8_t BPB_SecPerClus;
60 	uint8_t BPB_RsvdSecCnt[2];
61 	uint8_t BPB_NumFATs;
62 	uint8_t BPB_RootEntCnt[2];
63 	uint8_t BPB_TotSec16[2];
64 	uint8_t BPB_Media;
65 	uint8_t BPB_FATSz16[2];
66 	uint8_t BPB_SecPerTrack[2];
67 	uint8_t BPB_NumHeads[2];
68 	uint8_t BPB_HiddSec[4];
69 	uint8_t BPB_TotSec32[4];
70 	/* FAT12/FAT16 only fields */
71 	uint8_t BS_DrvNum;
72 	uint8_t BS_Reserved1;
73 	uint8_t BS_BootSig;
74 	uint8_t BS_VolID[4];
75 	uint8_t BS_VolLab[11];
76 	uint8_t BS_FilSysType[8];
77 } FAT_BSBPB; /* 62 bytes */
78 
79 /*
80  * FAT boot sector and boot parameter block for
81  * FAT32 volumes
82  */
83 typedef struct fat32_bsbpb {
84 	/* common fields */
85 	uint8_t BS_jmpBoot[3];
86 	uint8_t BS_OEMName[8];
87 	uint8_t BPB_BytsPerSec[2];
88 	uint8_t BPB_SecPerClus;
89 	uint8_t BPB_RsvdSecCnt[2];
90 	uint8_t BPB_NumFATs;
91 	uint8_t BPB_RootEntCnt[2];
92 	uint8_t BPB_TotSec16[2];
93 	uint8_t BPB_Media;
94 	uint8_t BPB_FATSz16[2];
95 	uint8_t BPB_SecPerTrack[2];
96 	uint8_t BPB_NumHeads[2];
97 	uint8_t BPB_HiddSec[4];
98 	uint8_t BPB_TotSec32[4];
99 	/* FAT32 only fields */
100 	uint8_t BPB_FATSz32[4];
101 	uint8_t BPB_ExtFlags[2];
102 	uint8_t BPB_FSVer[2];
103 	uint8_t BPB_RootClus[4];
104 	uint8_t BPB_FSInfo[2];
105 	uint8_t BPB_BkBootSec[2];
106 	uint8_t BPB_Reserved[12];
107 	uint8_t BS_DrvNum;
108 	uint8_t BS_Reserved1;
109 	uint8_t BS_BootSig;
110 	uint8_t BS_VolID[4];
111 	uint8_t BS_VolLab[11];
112 	uint8_t BS_FilSysType[8];
113 } FAT32_BSBPB; /* 90 bytes */
114 
115 /*
116  * FAT directory entry structure
117  */
118 #define	FAT_DES_ATTR_READ_ONLY	0x01
119 #define	FAT_DES_ATTR_HIDDEN	0x02
120 #define	FAT_DES_ATTR_SYSTEM	0x04
121 #define	FAT_DES_ATTR_VOLUME_ID	0x08
122 #define	FAT_DES_ATTR_DIRECTORY	0x10
123 #define	FAT_DES_ATTR_ARCHIVE	0x20
124 #define	FAT_DES_ATTR_LONG_NAME	(FAT_DES_ATTR_READ_ONLY |		\
125 				 FAT_DES_ATTR_HIDDEN |			\
126 				 FAT_DES_ATTR_SYSTEM |			\
127 				 FAT_DES_ATTR_VOLUME_ID)
128 
129 typedef struct fat_des {
130 	uint8_t DIR_Name[11];
131 	uint8_t DIR_Attr;
132 	uint8_t DIR_NTRes;
133 	uint8_t DIR_CrtTimeTenth;
134 	uint8_t DIR_CrtTime[2];
135 	uint8_t DIR_CrtDate[2];
136 	uint8_t DIR_LstAccDate[2];
137 	uint8_t DIR_FstClusHI[2];
138 	uint8_t DIR_WrtTime[2];
139 	uint8_t DIR_WrtDate[2];
140 	uint8_t DIR_FstClusLO[2];
141 	uint8_t DIR_FileSize[4];
142 } FAT_DES;
143