// Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// f32\sfat32\sl_bpb32.cpp

// Boot sector code, specific for EFat32.fsy

// 

//

/**

 @file

 @internalTechnology

*/

#include "sl_std.h"

//-------------------------------------------------------------------------------------------------------------------

TFatBootSector::TFatBootSector()

{

    Initialise();    

}

/** initialises the boot sector data */

void TFatBootSector::Initialise()

{

    Mem::FillZ(this, sizeof(TFatBootSector));

}

//-------------------------------------------------------------------------------------------------------------------

/**

    @return ETrue if the boot sector contents seems to be valid

*/

TBool TFatBootSector::IsValid() const

{

    const TFatType fatType = FatType(); //-- it will check SectorsPerCluster etc.

    if(fatType == EInvalid || ReservedSectors() < 1 || NumberOfFats() < 1)

        goto Invalid;

    if(fatType == EFat32)

    {

        if(VersionNumber()!= 0 || FatSectors()!=0 || FatSectors32()<1 || RootClusterNum()<KFatFirstSearchCluster ||

           TotalSectors()!=0 || HugeSectors() <5 || RootDirEntries() !=0)

        {

            goto Invalid; //-- these values are not compliant with FAT specs

        }

    }

    else //-- FAT12/16

    {

        if(TotalSectors() >0 && HugeSectors() >0 )

            goto Invalid; //-- values clash

        const TUint32 totSectors = Max((TUint32)TotalSectors(), HugeSectors());

        const TUint32 rootDirStartSec =  ReservedSectors() + FatSectors()*NumberOfFats(); //-- root directory start sector

        if(FatSectors() < 1 || rootDirStartSec < 3 || RootDirEntries() < 1 || totSectors < 5)

            goto Invalid; //-- these values are not compliant with FAT specs

    }

    return ETrue;

  Invalid:

    __PRINT(_L("TFatBootSector::IsValid() failed!"));

    return EFalse;

}

//-------------------------------------------------------------------------------------------------------------------

/**

    Initialize boot sector object from the given bufer. Does not validate the data.

    @param  aBuf buffer with data.

*/

void TFatBootSector::Internalize(const TDesC8& aBuf)

{

    ASSERT(aBuf.Size() >= KSizeOfFatBootSector);

    Initialise();

    TInt pos=0;

    Mem::Copy(&iJumpInstruction, &aBuf[pos],3);     pos+=3; // 0    TUint8 iJumpInstruction[3]

    Mem::Copy(&iVendorId,&aBuf[pos],KVendorIdSize); pos+=KVendorIdSize; // 3    TUint8 iVendorId[KVendorIdSize]

    Mem::Copy(&iBytesPerSector,&aBuf[pos],2);       pos+=2; // 11   TUint16 iBytesPerSector

    Mem::Copy(&iSectorsPerCluster,&aBuf[pos],1);    pos+=1; // 13   TUint8 iSectorsPerCluster   

    Mem::Copy(&iReservedSectors,&aBuf[pos],2);      pos+=2; // 14   TUint16 iReservedSectors

    Mem::Copy(&iNumberOfFats,&aBuf[pos],1);         pos+=1; // 16   TUint8 iNumberOfFats

    Mem::Copy(&iRootDirEntries,&aBuf[pos],2);       pos+=2; // 17   TUint16 iRootDirEntries

    Mem::Copy(&iTotalSectors,&aBuf[pos],2);         pos+=2; // 19   TUint16 iTotalSectors

    Mem::Copy(&iMediaDescriptor,&aBuf[pos],1);      pos+=1; // 21   TUint8 iMediaDescriptor

    Mem::Copy(&iFatSectors,&aBuf[pos],2);           pos+=2; // 22   TUint16 iFatSectors

    Mem::Copy(&iSectorsPerTrack,&aBuf[pos],2);      pos+=2; // 24   TUint16 iSectorsPerTrack

    Mem::Copy(&iNumberOfHeads,&aBuf[pos],2);        pos+=2; // 26   TUint16 iNumberOfHeads

    Mem::Copy(&iHiddenSectors,&aBuf[pos],4);        pos+=4; // 28   TUint32 iHiddenSectors

    Mem::Copy(&iHugeSectors,&aBuf[pos],4);          pos+=4; // 32   TUint32 iHugeSectors

    if(RootDirEntries() == 0) //-- we have FAT32 volume

    {

        Mem::Copy(&iFatSectors32, &aBuf[pos],4);    pos+=4; // 36 TUint32 iFatSectors32     

        Mem::Copy(&iFATFlags, &aBuf[pos],2);        pos+=2; // 40 TUint16 iFATFlags

        Mem::Copy(&iVersionNumber, &aBuf[pos],2);   pos+=2; // 42 TUint16 iVersionNumber

        Mem::Copy(&iRootClusterNum, &aBuf[pos],4);  pos+=4; // 44 TUint32 iRootClusterNum

        Mem::Copy(&iFSInfoSectorNum, &aBuf[pos],2); pos+=2; // 48 TUint16 iFSInfoSectorNum

        Mem::Copy(&iBkBootRecSector, &aBuf[pos],2);         // 50 TUint16 iBkBootRecSector

        pos+=(2+12);    //extra 12 for the reserved bytes   

    }

    Mem::Copy(&iPhysicalDriveNumber,&aBuf[pos],1);  pos+=1;// 36|64 TUint8 iPhysicalDriveNumber

    Mem::Copy(&iReserved,&aBuf[pos],1);             pos+=1;// 37|65 TUint8 iReserved

    Mem::Copy(&iExtendedBootSignature,&aBuf[pos],1);pos+=1;// 38|66 TUint8 iExtendedBootSignature

    Mem::Copy(&iUniqueID,&aBuf[pos],4);             pos+=4;// 39|67 TUint32 iUniqueID

    Mem::Copy(&iVolumeLabel,&aBuf[pos],KVolumeLabelSize);  // 43|71 TUint8 iVolumeLabel[KVolumeLabelSize]

    pos+=KVolumeLabelSize;

    // 54|82    TUint8 iFileSysType[KFileSysTypeSize]

    ASSERT(aBuf.Size() >= pos+KFileSysTypeSize);

    Mem::Copy(&iFileSysType,&aBuf[pos],KFileSysTypeSize);

}

//-------------------------------------------------------------------------------------------------------------------

/**

    Externalize boot sector object to the given data buffer.

    @param  aBuf buffer to externalize.

*/

void TFatBootSector::Externalize(TDes8& aBuf) const

{

    ASSERT(aBuf.MaxSize() >= KSizeOfFatBootSector);

    if(aBuf.Size() < KSizeOfFatBootSector)

        aBuf.SetLength(KSizeOfFatBootSector);

    TInt pos=0;

    Mem::Copy(&aBuf[pos],&iJumpInstruction,3);      pos+=3;

    Mem::Copy(&aBuf[pos],&iVendorId,KVendorIdSize); pos+=8;

    Mem::Copy(&aBuf[pos],&iBytesPerSector,2);       pos+=2;

    Mem::Copy(&aBuf[pos],&iSectorsPerCluster,1);    pos+=1;

    Mem::Copy(&aBuf[pos],&iReservedSectors,2);      pos+=2;

    Mem::Copy(&aBuf[pos],&iNumberOfFats,1);         pos+=1;

    Mem::Copy(&aBuf[pos],&iRootDirEntries,2);       pos+=2;

    Mem::Copy(&aBuf[pos],&iTotalSectors,2);         pos+=2;

    Mem::Copy(&aBuf[pos],&iMediaDescriptor,1);      pos+=1;

    Mem::Copy(&aBuf[pos],&iFatSectors,2);           pos+=2;

    Mem::Copy(&aBuf[pos],&iSectorsPerTrack,2);      pos+=2;

    Mem::Copy(&aBuf[pos],&iNumberOfHeads,2);        pos+=2;

    Mem::Copy(&aBuf[pos],&iHiddenSectors,4);        pos+=4;

    Mem::Copy(&aBuf[pos],&iHugeSectors,4);          pos+=4;

    if(iFatSectors == 0)    

        {

        Mem::Copy(&aBuf[pos], &iFatSectors32,4);    pos+=4;

        Mem::Copy(&aBuf[pos], &iFATFlags, 2);       pos+=2;

        Mem::Copy(&aBuf[pos], &iVersionNumber, 2);  pos+=2;

        Mem::Copy(&aBuf[pos], &iRootClusterNum, 4); pos+=4;

        Mem::Copy(&aBuf[pos], &iFSInfoSectorNum, 2);pos+=2;

        Mem::Copy(&aBuf[pos], &iBkBootRecSector, 2);pos+=2;

        //extra 12 for the reserved bytes   

        ASSERT(aBuf.Size() >= pos+12);

        Mem::FillZ(&aBuf[pos],12);

        pos+=12;

        }

    Mem::Copy(&aBuf[pos],&iPhysicalDriveNumber,1);  pos+=1;

    Mem::FillZ(&aBuf[pos],1);                       pos+=1;

    Mem::Copy(&aBuf[pos],&iExtendedBootSignature,1);pos+=1;

    Mem::Copy(&aBuf[pos],&iUniqueID,4);             pos+=4;

    Mem::Copy(&aBuf[pos],&iVolumeLabel,KVolumeLabelSize); 

    pos+=KVolumeLabelSize;

    ASSERT(aBuf.MaxSize() >= pos+KFileSysTypeSize);

    Mem::Copy(&aBuf[pos],&iFileSysType,KFileSysTypeSize);

}

//-------------------------------------------------------------------------------------------------------------------

#ifdef _DEBUG

/** replaces all non-printable characters in a buffer with spaces */

static void FixDes(TDes& aDes)

{

    for(TInt i=0; i< aDes.Length(); ++i)

    {

        TChar ch=aDes[i];

        if(!ch.IsPrint())

            aDes[i]=' ';    

    }

}

#endif

/** 

    Print out the boot sector info.

*/

void TFatBootSector::PrintDebugInfo() const

{

#ifdef _DEBUG

    __PRINT(_L("\n"));

    __PRINT(_L("======== BootSector info: ======="));

    TBuf<40> buf;

    buf.Copy(FileSysType()); FixDes(buf);    

    __PRINT1(_L("FAT type:%S"), &buf);

    buf.Copy(VendorId()); FixDes(buf);    

    __PRINT1(_L("Vendor ID:%S"), &buf);

    __PRINT1(_L("BytesPerSector:%d"),BytesPerSector());

    __PRINT1(_L("SectorsPerCluster:%d"),SectorsPerCluster());

    __PRINT1(_L("ReservedSectors:%d"),ReservedSectors());

    __PRINT1(_L("NumberOfFats:%d"),NumberOfFats());

    __PRINT1(_L("RootDirEntries:%d"),RootDirEntries());

    __PRINT1(_L("Total Sectors:%d"),TotalSectors());

    __PRINT1(_L("MediaDescriptor:0x%x"),MediaDescriptor());

    __PRINT1(_L("FatSectors:%d"),FatSectors());

    __PRINT1(_L("SectorsPerTrack:%d"),SectorsPerTrack());

    __PRINT1(_L("NumberOfHeads:%d"),NumberOfHeads());

    __PRINT1(_L("HugeSectors:%u"),HugeSectors());

    __PRINT1(_L("Fat32 Sectors:%u"),FatSectors32());

    __PRINT1(_L("Fat32 Flags:%d"),FATFlags());

    __PRINT1(_L("Fat32 Version Number:%d"),VersionNumber());

    __PRINT1(_L("Root Cluster Number:%u"),RootClusterNum());

    __PRINT1(_L("FSInfo Sector Number:%d"),FSInfoSectorNum());

    __PRINT1(_L("Backup Boot Rec Sector Number:%d"),BkBootRecSector());

    __PRINT1(_L("PhysicalDriveNumber:%d"),PhysicalDriveNumber());

    __PRINT1(_L("ExtendedBootSignature:%d"),ExtendedBootSignature());

    __PRINT1(_L("UniqueID:0x%x"),UniqueID());

    buf.Copy(VolumeLabel()); FixDes(buf);    

    __PRINT1(_L("VolumeLabel:%S"), &buf);

    __PRINT(_L("=============================\n"));

#endif

}

//-------------------------------------------------------------------------------------------------------------------

/**

    Determine FAT type according to the information from boot sector, see FAT32 specs.

    @return  FAT type. 

*/

TFatType TFatBootSector::FatType(void) const

    {

    //-- check iBytesPerSector validity; it shall be one of: 512,1024,2048,4096

    if(iBytesPerSector < 512 ||  iBytesPerSector > 4096 || !IsPowerOf2(iBytesPerSector))

        return EInvalid; //-- invalid iBytesPerSector value

    //-- check iSectorsPerCluster validity, it shall be one of: 1,2,4,8...128

    if(!IsPowerOf2(iSectorsPerCluster) || iSectorsPerCluster > 128)

        return EInvalid; //-- invalid iSectorsPerCluster value

    const TUint32 rootDirSectors = (iRootDirEntries*KSizeOfFatDirEntry + (iBytesPerSector-1)) / iBytesPerSector;

    const TUint32 fatSz = iFatSectors ? iFatSectors : iFatSectors32;

    const TUint32 totSec = iTotalSectors ? iTotalSectors : iHugeSectors;

    const TUint32 dataSec = totSec - (iReservedSectors + (iNumberOfFats * fatSz) + rootDirSectors);

    const TUint32 clusterCnt = dataSec / iSectorsPerCluster;

    //-- magic. see FAT specs for details.

    if(clusterCnt < 4085)

        return EFat12;

    else if(clusterCnt < 65525)

        return EFat16;

    else

        return EFat32;

    }

/** @return The first Fat sector number */

TInt TFatBootSector::FirstFatSector() const

{

    __ASSERT_DEBUG(IsValid(), Fault(EFatBadBootSectorParameter));

    return ReservedSectors();

}

/**

    @return Number of sectors in root directory. 0 for FAT32

*/

TUint32 TFatBootSector::RootDirSectors() const

{

    __ASSERT_DEBUG(IsValid(), Fault(EFatBadBootSectorParameter));

    return ( (RootDirEntries()*KSizeOfFatDirEntry + (BytesPerSector()-1)) / BytesPerSector() );

}

/** @return Start sector number of the root directory */

TInt TFatBootSector::RootDirStartSector()  const

{

    __ASSERT_DEBUG(IsValid(), Fault(EFatBadBootSectorParameter));

    const TUint32 firstNonFatSec = ReservedSectors() + TotalFatSectors()*NumberOfFats();

    if(FatType() == EFat32)

    {//-- FAT32 root dir is a file, calculate the position by it's 1st cluster number. FAT[0]+FAT[1] are reserved.

        return (firstNonFatSec + (RootClusterNum()-KFatFirstSearchCluster) * SectorsPerCluster());

    }

    else

    {//-- FAT12/16 root dir starts just after the FATs

        return firstNonFatSec;

    }

}

/** @return first data sector number. for FAT32 it includes the root directory */

TInt TFatBootSector::FirstDataSector() const

{

    return( ReservedSectors() + NumberOfFats()*TotalFatSectors() + RootDirSectors() );

}

/** @return FAT-type independent sector count on the volume */

TUint32 TFatBootSector::VolumeTotalSectorNumber() const

{

    __ASSERT_DEBUG(IsValid(), Fault(EFatBadBootSectorParameter));

    return TotalSectors() >0 ? TotalSectors() : HugeSectors();

}

/** @return FAT-type independent number of sectors in one FAT */

TUint32 TFatBootSector::TotalFatSectors() const

{

    __ASSERT_DEBUG(IsValid(), Fault(EFatBadBootSectorParameter));

    return FatSectors() >0 ? FatSectors() : FatSectors32();

}

//-------------------------------------------------------------------------------------------------------------------

const TUint32   KLeadSignature      = 0x41615252; ///< FSInfo Lead signiture value

const TUint32   KStructureSignature = 0x61417272; ///< FSInfo Structure signiture value

const TUint32   KTrailingSignature  = 0xAA550000; ///< FSInfo Trailing signiture

TFSInfo::TFSInfo()

{

    Initialise();

}

//-------------------------------------------------------------------------------------------------------------------

/** Initialise the data */

void TFSInfo::Initialise()  

{

    Mem::FillZ(this, sizeof(TFSInfo));

    iLeadSig      = KLeadSignature; 

    iStructureSig = KStructureSignature;

    iTrainlingSig = KTrailingSignature;

}

//-------------------------------------------------------------------------------------------------------------------

/**

    @return ETrue if FSInfo sector contents seems to be valid

*/

TBool TFSInfo::IsValid() const

{

    return (iLeadSig == KLeadSignature && iStructureSig == KStructureSignature && iTrainlingSig == KTrailingSignature);

}

//-------------------------------------------------------------------------------------------------------------------

/**

    Initialize FSInfo sector object from the given bufer. Does not validate the data.

    @param  aBuf buffer with data.

*/

void TFSInfo::Internalize(const TDesC8& aBuf)

{

    ASSERT((TUint32)aBuf.Size() >= KSizeOfFSInfo);

    TInt pos=0;

    Mem::Copy(&iLeadSig, &aBuf[pos],4);      pos+=(KFSInfoReserved1Size+4);

    Mem::Copy(&iStructureSig, &aBuf[pos],4); pos+=4;

    Mem::Copy(&iFreeCount,&aBuf[pos],4);     pos+=4;

    Mem::Copy(&iNextFree,&aBuf[pos],4);      pos+=(4+KFSInfoReserved2Size);

    Mem::Copy(&iTrainlingSig,&aBuf[pos],4);

}

//-------------------------------------------------------------------------------------------------------------------

/**

    Externalize FSInfo sector object to the given data buffer.

    @param  aBuf buffer to externalize.

*/

void TFSInfo::Externalize(TDes8& aBuf) const

{

    ASSERT((TUint32)aBuf.MaxSize() >= KSizeOfFSInfo);

    aBuf.SetLength(KSizeOfFSInfo);

    aBuf.FillZ();

    TInt pos=0;

    Mem::Copy(&aBuf[pos],&KLeadSignature,4);        pos+=4; 

                                                    pos+=KFSInfoReserved1Size;

    Mem::Copy(&aBuf[pos],&KStructureSignature,4);   pos+=4;

    Mem::Copy(&aBuf[pos],&iFreeCount,4);            pos+=4;

    Mem::Copy(&aBuf[pos],&iNextFree,4);             pos+=4;

                                                    pos+=KFSInfoReserved2Size;

    Mem::Copy(&aBuf[pos],&KTrailingSignature,4);

}

//-------------------------------------------------------------------------------------------------------------------

/** 

    Print out the FSInfo sector info.

*/

void TFSInfo::PrintDebugInfo() const

{

    __PRINT(_L("\n==== FSInfoSector : ===="));

    __PRINT1(_L("FSI_LeadSig:   0x%x"),iLeadSig);

    __PRINT1(_L("FSI_StrucSig:  0x%x"),iStructureSig);

    __PRINT1(_L("FSI_FreeCount: 0x%x"),iFreeCount);

    __PRINT1(_L("FSI_NxtFree:   0x%x"),iNextFree);

    __PRINT1(_L("FSI_TrailSig:  0x%x"),iTrainlingSig);

    __PRINT(_L("========================\n"));

}