fat.h@ 93488

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1	/* $Id: fat.h 93115 2022-01-01 11:31:46Z vboxsync $ */
2	/** @file
3	* IPRT, File Allocation Table (FAT).
4	*/
5
6	/*
7	* Copyright (C) 2017-2022 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27	#ifndef IPRT_INCLUDED_formats_fat_h
28	#define IPRT_INCLUDED_formats_fat_h
29	#ifndef RT_WITHOUT_PRAGMA_ONCE
30	# pragma once
31	#endif
32
33	#include <iprt/types.h>
34	#include <iprt/assertcompile.h>
35
36
37	/** @defgroup grp_rt_formats_fat File Allocation Table (FAT) structures and definitions
38	* @ingroup grp_rt_formats
39	* @{
40	*/
41
42
43	/** @name FAT Media byte values
44	* @remarks This isn't as simple as it's made out to be here!
45	* @{ */
46	#define FATBPB_MEDIA_FLOPPY_8 UINT8_C(0xe5)
47	#define FATBPB_MEDIA_FLOPPY_5_DOT_25 UINT8_C(0xed)
48	#define FATBPB_MEDIA_FLOPPY_3_DOT_5 UINT8_C(0xf0)
49	/* incomplete, figure out as needed... */
50
51	/** Checks if @a a_bMedia is a valid media byte. */
52	#define FATBPB_MEDIA_IS_VALID(a_bMedia) ( (uint8_t)(a_bMedia) >= 0xf8 \
53	\|\| (uint8_t)(a_bMedia) == 0xf0 \
54	\|\| (uint8_t)(a_bMedia) == 0xf4 /* obscure - msdos 2.11 */ \
55	\|\| (uint8_t)(a_bMedia) == 0xf5 /* obscure - msdos 2.11 */ \
56	\|\| (uint8_t)(a_bMedia) == 0xed /* obscure - tandy 2000 */ \
57	\|\| (uint8_t)(a_bMedia) == 0xe5 /* obscure - tandy 2000 */ )
58	/** @} */
59
60	/** Checks if @a a_bFatId is a valid FAT ID byte.
61	* @todo uncertain whether 0xf4 and 0xf5 should be allowed here too. */
62	#define FAT_ID_IS_VALID(a_bFatId) ( (uint8_t)(a_bFatId) >= 0xf8 \
63	\|\| (uint8_t)(a_bFatId) == 0xf0 \
64	\|\| (uint8_t)(a_bFatId) == 0xf4 /* obscure - msdos 2.11 */ \
65	\|\| (uint8_t)(a_bFatId) == 0xf5 /* obscure - msdos 2.11 */ \
66	\|\| (uint8_t)(a_bFatId) == 0xed /* obscure, tandy 2000 */ \
67	\|\| (uint8_t)(a_bFatId) == 0xe5 /* obscure, tandy 2000 */ )
68
69	/**
70	* The DOS 2.0 BIOS parameter block (BPB).
71	*
72	* This was the first DOS version with a BPB.
73	*/
74	#pragma pack(1)
75	typedef struct FATBPB20
76	{
77	/** 0x0b / 0x00: The sector size in bytes. */
78	uint16_t cbSector;
79	/** 0x0d / 0x02: Number of sectors per cluster. */
80	uint8_t cSectorsPerCluster;
81	/** 0x0e / 0x03: Number of reserved sectors before the first FAT. */
82	uint16_t cReservedSectors;
83	/** 0x10 / 0x05: Number of FATs. */
84	uint8_t cFats;
85	/** 0x11 / 0x06: Max size of the root directory (0 for FAT32). */
86	uint16_t cMaxRootDirEntries;
87	/** 0x13 / 0x08: Total sector count, zero if 32-bit count is used. */
88	uint16_t cTotalSectors16;
89	/** 0x15 / 0x0a: Media ID. */
90	uint8_t bMedia;
91	/** 0x16 / 0x0b: Number of sectors per FAT (0 for FAT32). */
92	uint16_t cSectorsPerFat;
93	} FATBPB20;
94	#pragma pack()
95	AssertCompileSize(FATBPB20, 0xd);
96	/** Pointer to a DOS 2.0 BPB. */
97	typedef FATBPB20 *PFATBPB20;
98	/** Pointer to a const DOS 2.0 BPB. */
99	typedef FATBPB20 const *PCFATBPB20;
100
101
102	/**
103	* The DOS 3.0 BPB changes that survived.
104	*/
105	#pragma pack(1)
106	typedef struct FATBPB30CMN
107	{
108	/** DOS v2.0 BPB. */
109	FATBPB20 Bpb20;
110	/** 0x18 / 0x0d: Sectors per track. Zero means reserved and not used. */
111	uint16_t cSectorsPerTrack;
112	/** 0x1a / 0x0f: Number of heads. Zero means reserved and not used. */
113	uint16_t cTracksPerCylinder;
114	} FATBPB30CMN;
115	#pragma pack()
116	AssertCompileSize(FATBPB30CMN, 0x11);
117
118	/**
119	* The DOS 3.0 BPB.
120	*/
121	#pragma pack(1)
122	typedef struct FATBPB30
123	{
124	/** DOS v3.0 BPB bits that survived. */
125	FATBPB30CMN Core30;
126	/** 0x1c / 0x11: Number of hidden sectors preceeding the volume. This is zero
127	* on unpartitioned media. */
128	uint16_t cHiddenSectors;
129	} FATBPB30;
130	#pragma pack()
131	AssertCompileSize(FATBPB30, 0x13);
132	/** Pointer to a DOS 3.0 BPB. */
133	typedef FATBPB30 *PFATBPB30;
134	/** Pointer to a const DOS 3.0 BPB. */
135	typedef FATBPB30 const *PCFATBPB30;
136
137	/**
138	* The DOS 3.0 BPB, flattened structure.
139	*/
140	#pragma pack(1)
141	typedef struct FATBPB30FLAT
142	{
143	/** @name New in DOS 2.0
144	* @{ */
145	/** 0x0b / 0x00: The sector size in bytes. */
146	uint16_t cbSector;
147	/** 0x0d / 0x02: Number of sectors per cluster. */
148	uint8_t cSectorsPerCluster;
149	/** 0x0e / 0x03: Number of reserved sectors before the first FAT. */
150	uint16_t cReservedSectors;
151	/** 0x10 / 0x05: Number of FATs. */
152	uint8_t cFats;
153	/** 0x11 / 0x06: Max size of the root directory (0 for FAT32). */
154	uint16_t cMaxRootDirEntries;
155	/** 0x13 / 0x08: Total sector count, zero if 32-bit count is used. */
156	uint16_t cTotalSectors16;
157	/** 0x15 / 0x0a: Media ID. */
158	uint8_t bMedia;
159	/** 0x16 / 0x0b: Number of sectors per FAT (0 for FAT32). */
160	uint16_t cSectorsPerFat;
161	/** @} */
162	/** @name New in DOS 3.0
163	* @{ */
164	/** 0x18 / 0x0d: Sectors per track. Zero means reserved and not used. */
165	uint16_t cSectorsPerTrack;
166	/** 0x1a / 0x0f: Number of heads. Zero means reserved and not used. */
167	uint16_t cTracksPerCylinder;
168	/** 0x1c / 0x11: Number of hidden sectors preceeding the volume. This is zero
169	* on unpartitioned media. */
170	uint16_t cHiddenSectors;
171	/** @} */
172	} FATBPB30FLAT;
173	#pragma pack()
174	AssertCompileSize(FATBPB30FLAT, 0x13);
175	/** Pointer to a flattened DOS 3.0 BPB. */
176	typedef FATBPB30FLAT *PFATBPB30FLAT;
177	/** Pointer to a const flattened DOS 3.0 BPB. */
178	typedef FATBPB30FLAT const *PCFATBPB30FLAT;
179
180
181	/**
182	* The DOS 3.2 BPB.
183	*/
184	#pragma pack(1)
185	typedef struct FATBPB32
186	{
187	/** DOS v3.0 BPB. */
188	FATBPB30 Bpb30;
189	/** 0x1e / 0x13: Number of sectors, including the hidden ones. This is ZERO
190	* in DOS 3.31+. */
191	uint16_t cAnotherTotalSectors;
192	} FATBPB32;
193	#pragma pack()
194	AssertCompileSize(FATBPB32, 0x15);
195	/** Pointer to a DOS 3.2 BPB. */
196	typedef FATBPB32 *PFATBPB32;
197	/** Pointer to const a DOS 3.2 BPB. */
198	typedef FATBPB32 const *PCFATBPB32;
199
200	/**
201	* The DOS 3.2 BPB, flattened structure.
202	*/
203	#pragma pack(1)
204	typedef struct FATBPB32FLAT
205	{
206	/** @name New in DOS 2.0
207	* @{ */
208	/** 0x0b / 0x00: The sector size in bytes. */
209	uint16_t cbSector;
210	/** 0x0d / 0x02: Number of sectors per cluster. */
211	uint8_t cSectorsPerCluster;
212	/** 0x0e / 0x03: Number of reserved sectors before the first FAT. */
213	uint16_t cReservedSectors;
214	/** 0x10 / 0x05: Number of FATs. */
215	uint8_t cFats;
216	/** 0x11 / 0x06: Max size of the root directory (0 for FAT32). */
217	uint16_t cMaxRootDirEntries;
218	/** 0x13 / 0x08: Total sector count, zero if 32-bit count is used. */
219	uint16_t cTotalSectors16;
220	/** 0x15 / 0x0a: Media ID. */
221	uint8_t bMedia;
222	/** 0x16 / 0x0b: Number of sectors per FAT (0 for FAT32). */
223	uint16_t cSectorsPerFat;
224	/** @} */
225	/** @name New in DOS 3.0
226	* @{ */
227	/** 0x18 / 0x0d: Sectors per track. Zero means reserved and not used. */
228	uint16_t cSectorsPerTrack;
229	/** 0x1a / 0x0f: Number of heads. Zero means reserved and not used. */
230	uint16_t cTracksPerCylinder;
231	/** 0x1c / 0x11: Number of hidden sectors preceeding the volume. This is zero
232	* on unpartitioned media. */
233	uint16_t cHiddenSectors;
234	/** @} */
235	/** @name New in DOS 3.2
236	* @{ */
237	/** 0x1e / 0x13: Number of sectors, including the hidden ones. This is ZERO
238	* in DOS 3.31+. */
239	uint16_t cAnotherTotalSectors;
240	/** @} */
241	} FATBPB32FLAT;
242	#pragma pack()
243	AssertCompileSize(FATBPB32FLAT, 0x15);
244	/** Pointer to a flattened DOS 3.2 BPB. */
245	typedef FATBPB32FLAT *PFATBPB32FLAT;
246	/** Pointer to a const flattened DOS 3.2 BPB. */
247	typedef FATBPB32FLAT const *PCFATBPB32FLAT;
248
249
250	/**
251	* The DOS 3.31 BPB.
252	*/
253	#pragma pack(1)
254	typedef struct FATBPB331
255	{
256	/** DOS v3.0 BPB bits that survived. */
257	FATBPB30CMN Core30;
258	/** 0x1c / 0x11: Number of hidden sectors preceeding the volume. This is zero
259	* on unpartitioned media. Values higher than 65535 are complicated due to
260	* the field overlapping FATBPB32::cAnotherTotalSectors */
261	uint32_t cHiddenSectors;
262	/** 0x20 / 0x15: Total logical sectors. Used if count >= 64K, otherwise
263	* FATBPB20::cTotalSectors16 is used. Zero if 64-bit value used with FAT32. */
264	uint32_t cTotalSectors32;
265	} FATBPB331;
266	#pragma pack()
267	AssertCompileSize(FATBPB331, 0x19);
268	/** Pointer to a DOS 3.31 BPB. */
269	typedef FATBPB331 *PFATBPB331;
270	/** Pointer to a const DOS 3.31 BPB. */
271	typedef FATBPB331 const *PCFATBPB331;
272
273	/**
274	* The DOS 3.31 BPB, flattened structure.
275	*/
276	#pragma pack(1)
277	typedef struct FATBPB331FLAT
278	{
279	/** @name New in DOS 2.0
280	* @{ */
281	/** 0x0b / 0x00: The sector size in bytes. */
282	uint16_t cbSector;
283	/** 0x0d / 0x02: Number of sectors per cluster. */
284	uint8_t cSectorsPerCluster;
285	/** 0x0e / 0x03: Number of reserved sectors before the first FAT (0 for
286	* NTFS). */
287	uint16_t cReservedSectors;
288	/** 0x10 / 0x05: Number of FATs (0 for NTFS). */
289	uint8_t cFats;
290	/** 0x11 / 0x06: Max size of the root directory (0 for FAT32 & NTFS). */
291	uint16_t cMaxRootDirEntries;
292	/** 0x13 / 0x08: Total sector count, zero if 32-bit count is used (and for
293	* NTFS). */
294	uint16_t cTotalSectors16;
295	/** 0x15 / 0x0a: Media ID. */
296	uint8_t bMedia;
297	/** 0x16 / 0x0b: Number of sectors per FAT (0 for FAT32 & NTFS). */
298	uint16_t cSectorsPerFat;
299	/** @} */
300	/** @name New in DOS 3.0
301	* @{ */
302	/** 0x18 / 0x0d: Sectors per track. Zero means reserved and not used. */
303	uint16_t cSectorsPerTrack;
304	/** 0x1a / 0x0f: Number of heads. Zero means reserved and not used. */
305	uint16_t cTracksPerCylinder;
306	/** @} */
307	/** @name New in DOS 3.31
308	* @{ */
309	/** 0x1c / 0x11: Number of hidden sectors preceeding the volume. This is zero
310	* on unpartitioned media. Values higher than 65535 are complicated due to
311	* the field overlapping FATBPB32::cAnotherTotalSectors */
312	uint32_t cHiddenSectors;
313	/** 0x20 / 0x15: Total logical sectors. Used if count >= 64K, otherwise
314	* FATBPB20::cTotalSectors16 is used. Zero if 64-bit value used with FAT32.
315	* (Zero for NTFS). */
316	uint32_t cTotalSectors32;
317	/** @} */
318	} FATBPB331FLAT;
319	#pragma pack()
320	AssertCompileSize(FATBPB331FLAT, 0x19);
321	/** Pointer to a flattened DOS 3.31 BPB. */
322	typedef FATBPB331FLAT *PFATBPB331FLAT;
323	/** Pointer to a const flattened DOS 3.31 BPB. */
324	typedef FATBPB331FLAT const *PCFATBPB331FLAT;
325
326
327	/**
328	* Extended BIOS parameter block (EBPB).
329	*/
330	#pragma pack(1)
331	typedef struct FATEBPB
332	{
333	/** The BPB. */
334	FATBPB331FLAT Bpb;
335
336	/** 0x24 / 0x19: BIOS INT13 pysical drive number. */
337	uint8_t bInt13Drive;
338	/** 0x25 / 0x1a: Reserved. NT used bit 0 for indicating dirty FS, and bit 1
339	* for surface scan. */
340	uint8_t bReserved;
341	/** 0x26 / 0x1b: Extended boot signature, FATEBPB_SIGNATURE or
342	* FATEBPB_SIGNATURE_OLD. */
343	uint8_t bExtSignature;
344	/** 0x27 / 0x1c: The volume serial number. */
345	uint32_t uSerialNumber;
346	/** 0x2b / 0x20: The volume label (space padded).
347	* @remarks Not available with FATEBPB_SIGNATURE_OLD */
348	char achLabel[11];
349	/** 0x36 / 0x2b: The file system type (space padded).
350	* @remarks Not available with FATEBPB_SIGNATURE_OLD */
351	char achType[8];
352	} FATEBPB;
353	#pragma pack()
354	AssertCompileSize(FATEBPB, 0x33);
355	/** Pointer to an extended BIOS parameter block. */
356	typedef FATEBPB *PFATEBPB;
357	/** Pointer to a const extended BIOS parameter block. */
358	typedef FATEBPB const *PCFATEBPB;
359
360	/** FATEBPB::bExtSignature value. */
361	#define FATEBPB_SIGNATURE UINT8_C(0x29)
362	/** FATEBPB::bExtSignature value used by OS/2 1.0-1.1 and PC DOS 3.4. These
363	* does not have the volume and file system type. */
364	#define FATEBPB_SIGNATURE_OLD UINT8_C(0x28)
365
366	/*FATEBPB::achType value for FAT12. /
367	#define FATEBPB_TYPE_FAT12 "FAT12 "
368	/*FATEBPB::achType value for FAT16. /
369	#define FATEBPB_TYPE_FAT16 "FAT16 "
370	/*FATEBPB::achType value for FAT12/FAT16. /
371	#define FATEBPB_TYPE_FAT "FAT32 "
372
373
374	/**
375	* FAT32 Extended BIOS parameter block (EBPB).
376	*/
377	#pragma pack(1)
378	typedef struct FAT32EBPB
379	{
380	/** The BPB. */
381	FATBPB331FLAT Bpb;
382
383	/** 0x24 / 0x19: Number of sectors per FAT.
384	* @note To avoid confusion with the FATEBPB signature, values which result in
385	* 0x00280000 or 0x00290000 when masked by 0x00ff0000 must not be used. */
386	uint32_t cSectorsPerFat32;
387	/** 0x28 / 0x1d: Flags pertaining to FAT mirroring and other stuff. */
388	uint16_t fFlags;
389	/** 0x2a / 0x1f: FAT32 version number (FAT32EBPB_VERSION_0_0). */
390	uint16_t uVersion;
391	/** 0x2c / 0x21: Cluster number of the root directory. */
392	uint32_t uRootDirCluster;
393	/** 0x30 / 0x25: Logical sector number of the information sector. */
394	uint16_t uInfoSectorNo;
395	/** 0x32 / 0x27: Logical sector number of boot sector copy. */
396	uint16_t uBootSectorCopySectorNo;
397	/** 0x34 / 0x29: Reserved, zero (or 0xf6) filled, preserve. */
398	uint8_t abReserved[12];
399
400	/** 0x40 / 0x35: BIOS INT13 pysical drive number
401	* @remarks Same as FATEBPB::bInt13Drive. */
402	uint8_t bInt13Drive;
403	/** 0x41 / 0x36: Reserved.
404	* @remarks Same as FATEBPB::bReserved. */
405	uint8_t bReserved;
406	/** 0x42 / 0x37: Extended boot signature (FATEBPB_SIGNATURE, or
407	* FATEBPB_SIGNATURE_OLD in some special cases).
408	* @remarks Same as FATEBPB::bExtSignature. */
409	uint8_t bExtSignature;
410	/** 0x43 / 0x38: The volume serial number.
411	* @remarks Same as FATEBPB::uSerialNumber. */
412	uint32_t uSerialNumber;
413	/** 0x47 / 0x3c: The volume label (space padded).
414	* @remarks Not available with FATEBPB_SIGNATURE_OLD
415	* @remarks Same as FATEBPB::achLabel. */
416	char achLabel[11];
417	/** 0x52 / 0x47: The file system type (space padded), or 64-bit logical sector
418	* count if both other count fields are zero. In the latter case, the type is
419	* moved to the OEM name field (FATBOOTSECTOR::achOemName).
420	*
421	* @remarks Not available with FATEBPB_SIGNATURE_OLD
422	* @remarks Same as FATEBPB::achType. */
423	union
424	{
425	/** Type string variant. */
426	char achType[8];
427	/** Total sector count if 4G or higher. */
428	uint64_t cTotalSectors64;
429	} u;
430	} FAT32EBPB;
431	#pragma pack()
432	AssertCompileSize(FAT32EBPB, 0x4f);
433	/** Pointer to a FAT32 extended BIOS parameter block. */
434	typedef FAT32EBPB *PFAT32EBPB;
435	/** Pointer to a const FAT32 extended BIOS parameter block. */
436	typedef FAT32EBPB const *PCFAT32EBPB;
437
438	/** FAT32 version 0.0 (FAT32EBPB::uVersion). */
439	#define FAT32EBPB_VERSION_0_0 UINT16_C(0x0000)
440
441
442	/**
443	* NTFS extended BIOS parameter block (NTFSEBPB).
444	*/
445	#pragma pack(1)
446	typedef struct NTFSEBPB
447	{
448	/** The BPB. */
449	FATBPB331FLAT Bpb;
450
451	/** 0x24 / 0x19: BIOS INT13 pysical drive number.
452	* @note Same location as FATEBPB::bInt13Drive. */
453	uint8_t bInt13Drive;
454	/** 0x25 / 0x1a: Reserved / flags */
455	uint8_t bReserved;
456	/** 0x26 / 0x1b: Extended boot signature (NTFSEBPB_SIGNATURE).
457	* @note Same location as FATEBPB::bExtSignature. */
458	uint8_t bExtSignature;
459	/** 0x27 / 0x1c: Reserved */
460	uint8_t bReserved2;
461
462	/** 0x28 / 0x1d: Number of sectors. */
463	uint64_t cSectors;
464	/** 0x30 / 0x25: Logical cluster number of the master file table (MFT). */
465	uint64_t uLcnMft;
466	/** 0x38 / 0x2d: Logical cluster number of the MFT mirror. */
467	uint64_t uLcnMftMirror;
468	/** 0x40 / 0x35: Logical clusters per file record segment.
469	* This is a shift count if negative. */
470	int8_t cClustersPerMftRecord;
471	/** 0x41 / 0x36: Reserved. */
472	uint8_t abReserved3[3];
473	/** 0x44 / 0x39: The default logical clusters count per index node.
474	* This is a shift count if negative. */
475	int8_t cClustersPerIndexNode;
476	/** 0x45 / 0x3a: Reserved. */
477	uint8_t abReserved4[3];
478	/** 0x48 / 0x3d: Volume serial number.
479	* @note This is larger than the the FAT serial numbers. */
480	uint64_t uSerialNumber;
481	/** 0x50 / 0x45: Checksum. */
482	uint32_t uChecksum;
483	} NTFSEBPB;
484	#pragma pack()
485	AssertCompileSize(NTFSEBPB, 0x49);
486	/** Pointer to a NTFS extended BIOS parameter block. */
487	typedef NTFSEBPB *PNTFSEBPB;
488	/** Pointer to a const NTFS extended BIOS parameter block. */
489	typedef NTFSEBPB const *PCNTFSEBPB;
490
491	/** NTFS EBPB signature (NTFSEBPB::bExtSignature). */
492	#define NTFSEBPB_SIGNATURE UINT8_C(0x80)
493
494
495	/**
496	* FAT boot sector layout.
497	*/
498	#pragma pack(1)
499	typedef struct FATBOOTSECTOR
500	{
501	/** 0x000: DOS 2.0+ jump sequence. */
502	uint8_t abJmp[3];
503	/** 0x003: OEM name (who formatted this volume). */
504	char achOemName[8];
505	/** 0x00b: The BIOS parameter block.
506	* This varies a lot in size. */
507	union
508	{
509	FATBPB20 Bpb20;
510	FATBPB30FLAT Bpb30;
511	FATBPB32FLAT Bpb32;
512	FATBPB331FLAT Bpb331;
513	FATEBPB Ebpb;
514	FAT32EBPB Fat32Ebpb;
515	NTFSEBPB Ntfs;
516	} Bpb;
517	/** 0x05a: Bootloader code/data/stuff. */
518	uint8_t abStuff[0x1a3];
519	/** 0x1fd: Old drive number location (DOS 3.2-3.31). */
520	uint8_t bOldInt13Drive;
521	/** 0x1fe: DOS signature (FATBOOTSECTOR_SIGNATURE). */
522	uint16_t uSignature;
523	} FATBOOTSECTOR;
524	#pragma pack()
525	AssertCompileSize(FATBOOTSECTOR, 0x200);
526	/** Pointer to a FAT boot sector. */
527	typedef FATBOOTSECTOR *PFATBOOTSECTOR;
528	/** Pointer to a const FAT boot sector. */
529	typedef FATBOOTSECTOR const *PCFATBOOTSECTOR;
530
531	/** Boot sector signature (FATBOOTSECTOR::uSignature). */
532	#define FATBOOTSECTOR_SIGNATURE UINT16_C(0xaa55)
533
534
535
536	/**
537	* FAT32 info sector (follows the boot sector).
538	*/
539	typedef struct FAT32INFOSECTOR
540	{
541	/** 0x000: Signature \#1 (FAT32INFOSECTOR_SIGNATURE_1). */
542	uint32_t uSignature1;
543	/** Reserved, should be zero. */
544	uint8_t abReserved1[0x1E0];
545	/** 0x1e4: Signature \#1 (FAT32INFOSECTOR_SIGNATURE_2). */
546	uint32_t uSignature2;
547	/** 0x1e8: Last known number of free clusters (informational). */
548	uint32_t cFreeClusters;
549	/** 0x1ec: Last allocated cluster number (informational). This could be used as
550	* an allocation hint when searching for a free cluster. */
551	uint32_t cLastAllocatedCluster;
552	/** 0x1f0: Reserved, should be zero, preserve. */
553	uint8_t abReserved2[12];
554	/** 0x1fc: Signature \#3 (FAT32INFOSECTOR_SIGNATURE_3). */
555	uint32_t uSignature3;
556	} FAT32INFOSECTOR;
557	AssertCompileSize(FAT32INFOSECTOR, 0x200);
558	/** Pointer to a FAT32 info sector. */
559	typedef FAT32INFOSECTOR *PFAT32INFOSECTOR;
560	/** Pointer to a const FAT32 info sector. */
561	typedef FAT32INFOSECTOR const *PCFAT32INFOSECTOR;
562
563	#define FAT32INFOSECTOR_SIGNATURE_1 UINT32_C(0x41615252)
564	#define FAT32INFOSECTOR_SIGNATURE_2 UINT32_C(0x61417272)
565	#define FAT32INFOSECTOR_SIGNATURE_3 UINT32_C(0xaa550000)
566
567
568	/** @name Special FAT cluster numbers and limits.
569	* @{ */
570	#define FAT_FIRST_DATA_CLUSTER 2 /*< The first data cluster. /
571
572	#define FAT_MAX_FAT12_TOTAL_CLUSTERS UINT32_C(0x00000ff6) /*< Maximum number of clusters in a 12-bit FAT . /
573	#define FAT_MAX_FAT16_TOTAL_CLUSTERS UINT32_C(0x0000fff6) /*< Maximum number of clusters in a 16-bit FAT . /
574	#define FAT_MAX_FAT32_TOTAL_CLUSTERS UINT32_C(0x0ffffff6) /*< Maximum number of clusters in a 32-bit FAT . /
575
576	#define FAT_LAST_FAT12_DATA_CLUSTER UINT32_C(0x00000ff5) /*< The last possible data cluster for FAT12. /
577	#define FAT_LAST_FAT16_DATA_CLUSTER UINT32_C(0x0000fff5) /*< The last possible data cluster for FAT16. /
578	#define FAT_LAST_FAT32_DATA_CLUSTER UINT32_C(0x0ffffff5) /*< The last possible data cluster for FAT32. /
579
580	#define FAT_MAX_FAT12_DATA_CLUSTERS UINT32_C(0x00000ff4) /*< Maximum number of data clusters for FAT12. /
581	#define FAT_MAX_FAT16_DATA_CLUSTERS UINT32_C(0x0000fff4) /*< Maximum number of data clusters for FAT16. /
582	#define FAT_MAX_FAT32_DATA_CLUSTERS UINT32_C(0x0ffffff4) /*< Maximum number of data clusters for FAT32. /
583
584	#define FAT_MIN_FAT12_DATA_CLUSTERS UINT32_C(0x00000001) /*< Maximum number of data clusters for FAT12. /
585	#define FAT_MIN_FAT16_DATA_CLUSTERS UINT32_C(0x00000ff5) /*< Maximum number of data clusters for FAT16. /
586	#define FAT_MIN_FAT32_DATA_CLUSTERS UINT32_C(0x0000fff5) /*< Maximum number of data clusters for FAT32. /
587
588	#define FAT_FIRST_FAT12_EOC UINT32_C(0x00000ff8) /*< The first end-of-file-cluster number for FAT12. /
589	#define FAT_FIRST_FAT16_EOC UINT32_C(0x0000fff8) /*< The first end-of-file-cluster number for FAT16. /
590	#define FAT_FIRST_FAT32_EOC UINT32_C(0x0ffffff8) /*< The first end-of-file-cluster number for FAT32. /
591	/** @} */
592
593
594	/**
595	* FAT directory entry.
596	*/
597	typedef struct FATDIRENTRY
598	{
599	/** 0x00: The directory entry name.
600	* First character serves as a flag to indicate deleted or not. */
601	uint8_t achName[8+3];
602	/** 0x0b: Attributes (FAT_ATTR_XXX). */
603	uint8_t fAttrib;
604	/** 0x0c: NT case flags (FATDIRENTRY_CASE_F_XXX). */
605	uint8_t fCase;
606	/** 0x0d: Birth milliseconds (DOS 7.0+ w/VFAT). */
607	uint8_t uBirthCentiseconds;
608	/** 0x0e: Birth time (DOS 7.0+ w/VFAT). */
609	uint16_t uBirthTime;
610	/** 0x10: Birth date (DOS 7.0+ w/VFAT). */
611	uint16_t uBirthDate;
612	/** 0x12: Access date (DOS 7.0+ w/ACCDATA in Config.sys). */
613	uint16_t uAccessDate;
614	union
615	{
616	/** 0x14: High cluster word for FAT32. */
617	uint16_t idxClusterHigh;
618	/** 0x14: Index of extended attributes (FAT16/FAT12). */
619	uint16_t idxEAs;
620	} u;
621	/** 0x16: Modify time (PC-DOS 1.1+, MS-DOS 1.20+). */
622	uint16_t uModifyTime;
623	/** 0x18: Modify date. */
624	uint16_t uModifyDate;
625	/** 0x1a: The data cluster index. */
626	uint16_t idxCluster;
627	/** 0x1c: The file size. */
628	uint32_t cbFile;
629	} FATDIRENTRY;
630	AssertCompileSize(FATDIRENTRY, 0x20);
631	AssertCompileMemberOffset(FATDIRENTRY, fAttrib, 0x0b);
632	AssertCompileMemberOffset(FATDIRENTRY, fCase, 0x0c);
633	AssertCompileMemberOffset(FATDIRENTRY, uBirthCentiseconds, 0x0d);
634	AssertCompileMemberOffset(FATDIRENTRY, uBirthTime, 0x0e);
635	AssertCompileMemberOffset(FATDIRENTRY, uBirthDate, 0x10);
636	AssertCompileMemberOffset(FATDIRENTRY, uAccessDate, 0x12);
637	AssertCompileMemberOffset(FATDIRENTRY, u, 0x14);
638	AssertCompileMemberOffset(FATDIRENTRY, uModifyTime, 0x16);
639	AssertCompileMemberOffset(FATDIRENTRY, uModifyDate, 0x18);
640	AssertCompileMemberOffset(FATDIRENTRY, idxCluster, 0x1a);
641	AssertCompileMemberOffset(FATDIRENTRY, cbFile, 0x1c);
642	/** Pointer to a FAT directory entry. */
643	typedef FATDIRENTRY *PFATDIRENTRY;
644	/** Pointer to a FAT directory entry. */
645	typedef FATDIRENTRY const *PCFATDIRENTRY;
646
647
648	/** @name FAT_ATTR_XXX - FATDIRENTRY::fAttrib flags.
649	* @{ */
650	#define FAT_ATTR_READONLY UINT8_C(0x01)
651	#define FAT_ATTR_HIDDEN UINT8_C(0x02)
652	#define FAT_ATTR_SYSTEM UINT8_C(0x04)
653	#define FAT_ATTR_VOLUME UINT8_C(0x08)
654	#define FAT_ATTR_DIRECTORY UINT8_C(0x10)
655	#define FAT_ATTR_ARCHIVE UINT8_C(0x20)
656	#define FAT_ATTR_DEVICE UINT8_C(0x40)
657	#define FAT_ATTR_RESERVED UINT8_C(0x80)
658	#define FAT_ATTR_NAME_SLOT UINT8_C(0x0f) /*< Special attribute value for FATDIRNAMESLOT. /
659	/** @} */
660
661	/** @name FATDIRENTRY_CASE_F_XXX - FATDIRENTRY::fCase flags.
662	* @{ */
663	/** Lower cased base name (first 8 chars). */
664	#define FATDIRENTRY_CASE_F_LOWER_BASE UINT8_C(0x08)
665	/** Lower cased filename extension (last 3 chars). */
666	#define FATDIRENTRY_CASE_F_LOWER_EXT UINT8_C(0x10)
667	/** @} */
668
669	/** @name FATDIRENTRY_CH0_XXX - FATDIRENTRY::achName[0]
670	* @{ */
671	/** Deleted entry. */
672	#define FATDIRENTRY_CH0_DELETED UINT8_C(0xe5)
673	/** End of used directory entries (MS-DOS 1.25+, PC-DOS 2.0+). */
674	#define FATDIRENTRY_CH0_END_OF_DIR UINT8_C(0x00)
675	/** The special dot or dot-dot dir aliases (MS-DOS 1.40+, PC-DOS 2.0+).
676	* @remarks 0x2e is the ascii table entry of the '.' character. */
677	#define FATDIRENTRY_CH0_DOT_ALIAS UINT8_C(0x2e)
678	/** Escaped 0xe5 leadcharacter (DOS 3.0+). */
679	#define FATDIRENTRY_CH0_ESC_E5 UINT8_C(0x05)
680	/** @} */
681
682
683	/**
684	* FAT directory alias name slot.
685	*
686	* Each slot holds 13 UTF-16 (/ UCS-2) characters, so it takes 20 slots to cover
687	* a 255 character long name.
688	*/
689	#pragma pack(1)
690	typedef struct FATDIRNAMESLOT
691	{
692	/** The slot sequence number. */
693	uint8_t idSlot;
694	/** The first 5 name chars.
695	* @remarks misaligned */
696	RTUTF16 awcName0[5];
697	/** Attributes (FAT_ATTR_XXX). */
698	uint8_t fAttrib;
699	/** Always zero. */
700	uint8_t fZero;
701	/** Alias checksum. */
702	uint8_t bChecksum;
703	/** The next 6 name chars. */
704	RTUTF16 awcName1[6];
705	/** Always zero (usually cluster entry). */
706	uint16_t idxZero;
707	/** The next 2 name chars. */
708	RTUTF16 awcName2[2];
709	} FATDIRNAMESLOT;
710	#pragma pack()
711	AssertCompileSize(FATDIRNAMESLOT, 0x20);
712	/** Pointer to a FAT directory entry. */
713	typedef FATDIRNAMESLOT *PFATDIRNAMESLOT;
714	/** Pointer to a FAT directory entry. */
715	typedef FATDIRNAMESLOT const *PCFATDIRNAMESLOT;
716
717	/** Slot ID flag indicating that it's the first slot. */
718	#define FATDIRNAMESLOT_FIRST_SLOT_FLAG UINT8_C(0x40)
719	/** Highest slot ID recognized. This allows for 260 characters, however many
720	* implementation limits it to 255 or 250. */
721	#define FATDIRNAMESLOT_HIGHEST_SLOT_ID UINT8_C(0x14)
722	/** Max number of slots recognized. (This is the same as the higest slot ID
723	* because the 0 isn't a valid ID.) */
724	#define FATDIRNAMESLOT_MAX_SLOTS FATDIRNAMESLOT_HIGHEST_SLOT_ID
725	/** Number of UTF-16 units per slot. */
726	#define FATDIRNAMESLOT_CHARS_PER_SLOT (5 + 6 + 2)
727
728
729
730	/**
731	* FAT directory entry union.
732	*/
733	typedef union FATDIRENTRYUNION
734	{
735	/** Regular entry view. */
736	FATDIRENTRY Entry;
737	/** Name slot view. */
738	FATDIRNAMESLOT Slot;
739	} FATDIRENTRYUNION;
740	AssertCompileSize(FATDIRENTRYUNION, 0x20);
741	/** Pointer to a FAT directory entry union. */
742	typedef FATDIRENTRYUNION *PFATDIRENTRYUNION;
743	/** Pointer to a const FAT directory entry union. */
744	typedef FATDIRENTRYUNION const *PCFATDIRENTRYUNION;
745
746	/** @} */
747
748	#endif /* !IPRT_INCLUDED_formats_fat_h */
749

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source: vbox/trunk/include/iprt/formats/fat.h@ 93488

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