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
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 */
52typedef 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 */
81typedef 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
127typedef 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;