1 // Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies).
2 // All rights reserved.
3 // This component and the accompanying materials are made available
4 // under the terms of the License "Eclipse Public License v1.0"
5 // which accompanies this distribution, and is available
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
8 // Initial Contributors:
9 // Nokia Corporation - initial contribution.
14 // f32\sfat32\inc\sl_bpb.h
16 // @internalTechnology
25 #include "filesystem_fat.h"
26 using FileSystem_FAT::TFatSubType;
27 typedef TFatSubType TFatType;
30 const TInt KVolumeLabelSize =11; ///< Volume lable size
31 const TInt KFileSysTypeSize =8; ///< File system type parameter size
32 const TInt KVendorIdSize =8; ///< Vendor ID parameter size
33 const TInt KBootSectorSignature =0xAA55;///< File system Boot sector signiture
34 const TInt KFat16VolumeLabelPos =43; ///< Position of volume lable in BPB for Fat12/16
35 const TInt KFat32VolumeLabelPos =71; ///< Position of volume lable in BPB for Fat32
36 const TInt KSizeOfFatBootSector = 90; ///< Size in bytes of Boot sector parameter block (BPB)
38 const TUint32 KBootSectorNum =0; ///< Main Boot Sector number (always 0)
39 const TUint32 KFSInfoSectorNum =1; ///< Main FSInfo sector number. This is a default value. The actual value shall be taken from the BPB
40 const TUint32 KReservedBootSectorNum=2; ///< Reserved Boot Sector (always 2)
42 const TUint32 KBkBootSectorNum =6; ///< Backup Boot Sector number (must be 6 by default)
43 const TUint32 KBkFSInfoSectorNum =KBkBootSectorNum+1; ///< Backup FSInfo sector number, follows the backup bpb sector
44 const TUint32 KBkReservedBootSectorNum=KBkBootSectorNum+2; ///< Backup Reserved Boot Sector number, follows the backup FSInfo sector number
48 //-------------------------------------------------------------------------------------------------------------------
51 Boot sector parameter block, enables access to all file system parameters.
52 Data is populated at mount time from the BPB sector
57 //-- simple getters / setters
58 inline const TPtrC8 VendorId() const;
59 inline TUint16 BytesPerSector() const;
60 inline TInt SectorsPerCluster() const;
61 inline TInt ReservedSectors() const;
62 inline TInt NumberOfFats() const;
63 inline TInt RootDirEntries() const;
64 inline TInt TotalSectors() const;
65 inline TUint8 MediaDescriptor() const;
66 inline TInt FatSectors() const;
67 inline TInt SectorsPerTrack() const;
68 inline TInt NumberOfHeads() const;
69 inline TInt HiddenSectors() const;
70 inline TInt HugeSectors() const;
71 inline TInt PhysicalDriveNumber() const;
72 inline TInt ExtendedBootSignature() const;
73 inline TUint32 UniqueID() const;
74 inline const TPtrC8 VolumeLabel() const;
75 inline const TPtrC8 FileSysType() const;
76 inline TInt BootSectorSignature() const;
77 inline TUint32 FatSectors32() const;
78 inline TUint16 FATFlags() const;
79 inline TUint16 VersionNumber() const;
80 inline TUint32 RootClusterNum() const;
81 inline TUint16 FSInfoSectorNum() const;
82 inline TUint16 BkBootRecSector() const;
84 inline void SetJumpInstruction();
85 inline void SetVendorID(const TDesC8& aDes);
86 inline void SetBytesPerSector(TInt aBytesPerSector);
87 inline void SetSectorsPerCluster(TInt aSectorsPerCluster);
88 inline void SetReservedSectors(TInt aReservedSectors);
89 inline void SetNumberOfFats(TInt aNumberOfFats);
90 inline void SetRootDirEntries(TInt aRootDirEntries);
91 inline void SetTotalSectors(TInt aTotalSectors);
92 inline void SetMediaDescriptor(TUint8 aMediaDescriptor);
93 inline void SetFatSectors(TInt aFatSectors);
94 inline void SetSectorsPerTrack(TInt aSectorsPerTrack);
95 inline void SetNumberOfHeads(TInt aNumberOfHeads);
96 inline void SetHiddenSectors(TUint32 aHiddenSectors);
97 inline void SetHugeSectors(TUint32 aTotalSectors);
98 inline void SetPhysicalDriveNumber(TInt aPhysicalDriveNumber);
99 inline void SetReservedByte(TUint8 aReservedByte);
100 inline void SetExtendedBootSignature(TInt anExtendedBootSignature);
101 inline void SetUniqueID(TUint32 anUniqueID);
102 inline void SetVolumeLabel(const TDesC8& aDes);
103 inline void SetFileSysType(const TDesC8& aDes);
104 inline void SetFatSectors32(TUint32 aFatSectors32);
105 inline void SetFATFlags(TUint16 aFATFlags);
106 inline void SetVersionNumber(TUint16 aVersionNumber);
107 inline void SetRootClusterNum(TUint32 aRootCusterNum);
108 inline void SetFSInfoSectorNum(TUint16 aFSInfoSectorNum);
109 inline void SetBkBootRecSector(TUint16 aBkBootRecSector);
115 TBool IsValid() const;
116 TFatType FatType(void) const;
118 void Internalize(const TDesC8& aBuf);
119 void Externalize(TDes8& aBuf) const;
120 void PrintDebugInfo() const;
122 //-- more advanced API, works for all FAT types
123 TInt FirstFatSector() const;
124 TInt RootDirStartSector() const;
125 TInt FirstDataSector() const;
127 TUint32 VolumeTotalSectorNumber() const;
128 TUint32 TotalFatSectors() const;
129 TUint32 RootDirSectors() const;
133 TUint8 iJumpInstruction[3]; ///< +0 Jump instruction used for bootable volumes
134 TUint8 iVendorId[KVendorIdSize]; ///< +3 Vendor ID of the file system that formatted the volume
135 TUint16 iBytesPerSector; ///< +11/0x0b Bytes per sector
136 TUint8 iSectorsPerCluster; ///< +13/0x0d Sectors per cluster ratio
137 TUint16 iReservedSectors; ///< +14/0x0e Number of reserved sectors on the volume
138 TUint8 iNumberOfFats; ///< +16/0x10 Number of Fats on the volume
139 TUint16 iRootDirEntries; ///< +17/0x11 Number of entries allowed in the root directory, specific to Fat12/16, zero for FAT32
140 TUint16 iTotalSectors; ///< +19/0x13 Total sectors on the volume, zero for FAT32
141 TUint8 iMediaDescriptor; ///< +12/0x15 Media descriptor
142 TUint16 iFatSectors; ///< +22/0x16 Sectors used for the Fat table, zero for FAT32
143 TUint16 iSectorsPerTrack; ///< +24/0x18 Sectors per track
144 TUint16 iNumberOfHeads; ///< +26/0x1a Number of heads
145 TUint32 iHiddenSectors; ///< +28/0x1c Number of hidden sectors in the volume
146 TUint32 iHugeSectors; ///< +32/0x20 Total sectors in the volume, Used if totalSectors > 65535
147 TUint32 iFatSectors32; ///< +36/0x24 Start of additional elements @ offset 36 for FAT32, Sectors in Fat table for 32 bit volume
148 TUint16 iFATFlags; ///< +40/0x28 Fat flags
149 TUint16 iVersionNumber; ///< +42/0x2a Version number of the file system
150 TUint32 iRootClusterNum; ///< +44/0x2c Cluster number of the root directory
151 TUint16 iFSInfoSectorNum; ///< +48/0x30 Sector number containing the FSIInfo structure
152 TUint16 iBkBootRecSector; ///< +50/0x32 Backup boot sector
153 TUint8 iReserved2[12]; ///< +52/0x34 Reserved space, End of Fat32 Only parameters section
154 TUint8 iPhysicalDriveNumber; ///< +64/0x40 Physical drive number, not used in Symbian OS
155 TUint8 iReserved; ///< +65/0x41 Reserved byte
156 TUint8 iExtendedBootSignature; ///< +66/0x42 Extended boot signiture
157 TUint32 iUniqueID; ///< +67/0x43 Unique volume ID
158 TUint8 iVolumeLabel[KVolumeLabelSize]; ///< +71/0x47 The volume's label
159 TUint8 iFileSysType[KFileSysTypeSize]; ///< +82/0x52 File system type
165 //-------------------------------------------------------------------------------------------------------------------
167 const TUint32 KSizeOfFSInfo = 0x200; ///< Size in bytes of the FSInfo structures
168 const TUint32 KFSInfoReserved1Size= 480; ///< Size of first reserved area in FSInfo
169 const TUint32 KFSInfoReserved2Size= 12; ///< Size of second reserved area in FSInfo
172 TFSinfo hold the File system information comprising the free cluster count
173 and next free cluster. It is found in the sector after the BPB and contains
174 several identification signitures along with resverved space. It is not
175 mandatory to support this feature.
184 TBool IsValid() const;
185 void Internalize(const TDesC8& aBuf);
186 void Externalize(TDes8& aBuf) const;
187 void PrintDebugInfo() const;
191 inline TUint32 FreeClusterCount() const;
192 inline TUint32 NextFreeCluster() const;
194 inline void SetFreeClusterCount(TUint32 aFreeCount);
195 inline void SetNextFreeCluster(TUint32 aNextCluster);
198 TUint32 iLeadSig; ///< +0 lead in signature, should always equal 0x41615252
199 TUint8 iReserved1[KFSInfoReserved1Size]; ///< +4 First reserved region of 480 bytes
200 TUint32 iStructureSig; ///< +484/0x1e4 Structure signature, should equal 0x61417272
201 TUint32 iFreeCount; ///< +488/0x1e8 last known free cluster count
202 TUint32 iNextFree; ///< +492/0x1ec hint to file system as to where to start looking for free clusters
203 TUint8 iReserved2[KFSInfoReserved2Size]; ///< +496/0x1f0 Second reserved region of 12 bytes
204 TUint32 iTrainlingSig; ///< +508/0x1fc Trailing Signature (Bytes 510 and 511 = 55 and AA respectively)