1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 */
54typedef 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 */
83typedef 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
129typedef 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