sl@0: // Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of the License "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: // f32\sfat\sl_check.cpp
sl@0: // 
sl@0: //
sl@0: 
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: //!!
sl@0: //!! WARNING!! DO NOT edit this file !! '\sfat' component is obsolete and is not being used. '\sfat32'replaces it
sl@0: //!!
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: 
sl@0: #include "sl_std.h"
sl@0: #include "sl_scandrv.h"
sl@0: 
sl@0: const TInt KMaxBufferSize=8192;
sl@0: 
sl@0: 
sl@0: TBool CCheckFatTable::IsEof16Bit(TInt aCluster) const
sl@0: {
sl@0:     return(aCluster>=0xFFF8 && aCluster<=0xFFFF);
sl@0: }
sl@0: 
sl@0: TBool CCheckFatTable::IsEof12Bit(TInt aCluster) const
sl@0: {
sl@0:     return(aCluster>=0xFF8 && aCluster<=0xFFF);
sl@0: }
sl@0: 
sl@0: TInt CCheckFatTable::MaxFatIndex() const
sl@0:     {   
sl@0:     __ASSERT_DEBUG((TUint)iMaxFatIndex>=KFatFirstSearchCluster, Fault(ECheckFatIndexZero));
sl@0:     return(iMaxFatIndex);
sl@0:     }
sl@0: 
sl@0: 
sl@0: CCheckFatTable* CCheckFatTable::NewL(CFatMountCB* aOwner)
sl@0: //
sl@0: // Create a CCheckFatTable
sl@0: //
sl@0:     {
sl@0:     CCheckFatTable* fatTable;
sl@0:     fatTable=new(ELeave) CCheckFatTable(aOwner);
sl@0:     return(fatTable);
sl@0:     }
sl@0: 
sl@0: 
sl@0: CCheckFatTable::CCheckFatTable(CFatMountCB* aOwner)
sl@0: //
sl@0: // Constructor
sl@0: //
sl@0:     {
sl@0:     iOwner=aOwner;
sl@0:     }
sl@0: 
sl@0: CCheckFatTable::~CCheckFatTable()
sl@0: //
sl@0: // Destructor
sl@0: //
sl@0:     {
sl@0:     User::Free(iCheckFat);
sl@0:     }
sl@0: 
sl@0: 
sl@0: void CCheckFatTable::InitializeL()
sl@0: //
sl@0: // Initialize the check fat table
sl@0: //
sl@0:     {
sl@0:     __PRINT(_L("CCheckFatTable::InitializeL"));
sl@0: 
sl@0:     TInt fatSize=iOwner->FatSizeInBytes();
sl@0: 
sl@0:     if(iCheckFat==NULL)
sl@0:         iCheckFat=(TUint8*)User::AllocL(fatSize);
sl@0:     else
sl@0:         iCheckFat=(TUint8*)User::ReAllocL(iCheckFat,fatSize);
sl@0:     Mem::FillZ(iCheckFat,fatSize);
sl@0:     iMaxFatIndex=iOwner->UsableClusters()+1;
sl@0:     if(iOwner->Is16BitFat())
sl@0:         {
sl@0:         __ASSERT_ALWAYS(iMaxFatIndex>0 && iMaxFatIndex<EOF_16Bit && !IsEof16Bit(iMaxFatIndex),User::Leave(KErrCorrupt));
sl@0:         }
sl@0:     else
sl@0:         {
sl@0:         __ASSERT_ALWAYS(iMaxFatIndex>0 && iMaxFatIndex<EOF_12Bit && !IsEof12Bit(iMaxFatIndex),User::Leave(KErrCorrupt));
sl@0:         }
sl@0:     WriteMediaDescriptor();
sl@0:     
sl@0:     __PRINT2(_L("fatSize=%d,iCheckFat=0x%x"),fatSize,iCheckFat);
sl@0:     }
sl@0: 
sl@0: 
sl@0: /**
sl@0: @return ETrue if found errors in FAT 
sl@0: */
sl@0: TBool CCheckFatTable::FlushL()
sl@0: //
sl@0: // Flush iCheckFat to the media, comparing each sector to corresponding 
sl@0: // sector in all fats (cf.CFixedCache::FlushL)
sl@0: //  
sl@0:     {
sl@0:     TBool bErrFound = EFalse;
sl@0:     
sl@0:     __PRINT(_L("CCheckFatTable::FlushL()"));
sl@0:     HBufC8* hBuf=HBufC8::New(KMaxBufferSize);
sl@0:     if (hBuf==NULL)
sl@0:         hBuf=HBufC8::NewL(KMaxBufferSize/4);
sl@0:     CleanupStack::PushL(hBuf);
sl@0: 
sl@0:     TUint8* ptr=(TUint8*)hBuf->Ptr();
sl@0:     TInt maxSize=hBuf->Des().MaxSize();
sl@0: 
sl@0:     TPtr8 fatBuffer(ptr,maxSize);
sl@0:     TInt fatSize=iOwner->FatSizeInBytes();
sl@0:     TInt remainder=fatSize;
sl@0:     TInt offset=iOwner->StartOfFatInBytes();
sl@0:     TUint8* dataPtr=iCheckFat;
sl@0:     TFatDriveInterface& drive = iOwner->DriveInterface();
sl@0:     TInt fatNumber=iOwner->NumberOfFats();
sl@0:     
sl@0:     while(remainder)
sl@0:         {
sl@0:         TInt s=Min(fatBuffer.MaxSize(),remainder);
sl@0:         TInt fatCount=fatNumber;
sl@0:         TInt fatPos=0;
sl@0:         while(fatCount)
sl@0:             {
sl@0:             TInt fatOffset=offset+fatPos;
sl@0:             User::LeaveIfError(drive.ReadCritical(fatOffset,s,fatBuffer));
sl@0:             TInt rem2=s;
sl@0:             TInt offset2=fatOffset;
sl@0:             TUint8* dataPtr2=dataPtr;
sl@0:             TInt bufOffset=0;
sl@0:             while(rem2)
sl@0:                 {
sl@0:                 TInt s2=Min(rem2,512);
sl@0:                 TInt r=Mem::Compare(dataPtr2,s2,fatBuffer.Ptr()+bufOffset,s2);
sl@0:                 if (r!=0)
sl@0:                     {
sl@0:                     bErrFound = ETrue;
sl@0:                     TPtrC8 dataBuf(dataPtr2,s2);
sl@0:                     User::LeaveIfError(drive.WriteCritical(offset2,dataBuf));
sl@0:                     }
sl@0:                 rem2-=s2;
sl@0:                 offset2+=s2;
sl@0:                 dataPtr2+=s2;
sl@0:                 bufOffset+=s2;
sl@0:                 }
sl@0:             --fatCount;
sl@0:             fatPos+=fatSize;
sl@0:             }
sl@0:         offset+=s;
sl@0:         dataPtr+=s;
sl@0:         remainder-=s;
sl@0:         }
sl@0: 
sl@0:     CleanupStack::PopAndDestroy();
sl@0: 
sl@0:     return bErrFound;
sl@0:     }
sl@0: 
sl@0: void CCheckFatTable::WriteMediaDescriptor()
sl@0: //
sl@0: // Write media descriptor to first byte and 0xFF to
sl@0: // remaining bytes of first two entries
sl@0: //
sl@0:     {
sl@0:     __PRINT(_L("CCheckFatTable::WriteMediaDescriptor"));
sl@0:     iCheckFat[0]=KBootSectorMediaDescriptor;
sl@0:     iCheckFat[1]=0xFF;
sl@0:     iCheckFat[2]=0xFF;
sl@0:     if (iOwner->Is16BitFat())
sl@0:         iCheckFat[3]=0xFF;
sl@0:     }
sl@0: 
sl@0: TInt CCheckFatTable::PosInBytes(TInt aFatIndex) const
sl@0: //
sl@0: // Return number of bytes into the fat
sl@0: //
sl@0:     {
sl@0:     TInt fatPosInBytes;
sl@0:     if (iOwner->Is16BitFat())
sl@0:         fatPosInBytes=aFatIndex<<1;
sl@0:     else
sl@0:         // this is used since 8-bit access will be used for reading/writing
sl@0:         fatPosInBytes=(aFatIndex*3>>1);
sl@0:     return(fatPosInBytes);
sl@0:     }
sl@0: 
sl@0: 
sl@0: TInt CCheckFatTable::PosInIndex(TInt aBytePos) const
sl@0: //
sl@0: // Return index given byte position in fat
sl@0: //
sl@0:     {
sl@0:     if(iOwner->Is16BitFat())
sl@0:         return(aBytePos>>1);
sl@0:     else
sl@0:         return((aBytePos<<1)/3);
sl@0:     }
sl@0: 
sl@0: 
sl@0: TInt CCheckFatTable::ReadL(TInt aFatIndex) const
sl@0: //
sl@0: // Read a value from the check fat
sl@0: //
sl@0:     {
sl@0:     __ASSERT_ALWAYS((TUint32)aFatIndex >=KFatFirstSearchCluster && aFatIndex<=MaxFatIndex(),User::Leave(KErrCorrupt));
sl@0:     TUint clusterVal;
sl@0:     if(iOwner->Is16BitFat())
sl@0:         clusterVal=*(TUint16*)(iCheckFat+PosInBytes(aFatIndex));
sl@0:     else
sl@0:         {
sl@0:         TUint8* pCluster=iCheckFat+PosInBytes(aFatIndex);
sl@0:         clusterVal=pCluster[0]|(pCluster[1]<<8);
sl@0:         TBool oddCluster=(aFatIndex)&1;
sl@0:         if(oddCluster)
sl@0:             clusterVal>>=4;
sl@0:         clusterVal&=0xFFF;
sl@0:         }
sl@0:     return(clusterVal);
sl@0:     }
sl@0: 
sl@0: 
sl@0: void CCheckFatTable::WriteL(TInt aFatIndex,TInt aValue)
sl@0: //
sl@0: // Write a value to the check fat
sl@0: //
sl@0:     {
sl@0:     if(iOwner->Is16BitFat())
sl@0:         __ASSERT_ALWAYS((TUint32)aFatIndex>=KFatFirstSearchCluster && aFatIndex<=MaxFatIndex() && aValue>=0 && aValue<=0xFFFF,User::Leave(KErrCorrupt));
sl@0:     else
sl@0:         __ASSERT_ALWAYS((TUint32)aFatIndex>=KFatFirstSearchCluster && aFatIndex<=MaxFatIndex() && aValue>=0 && aValue<=0xFFF,User::Leave(KErrCorrupt));
sl@0:     TUint8* p=(TUint8*)(iCheckFat+PosInBytes(aFatIndex));
sl@0:     if (iOwner->Is16BitFat())
sl@0:         { 
sl@0:         *(TUint16*)p=(TUint16)aValue;
sl@0:         return;
sl@0:         }
sl@0:     TUint8 mask=0x0F;
sl@0:     TBool odd=(aFatIndex)&1;
sl@0:     TUint8 fatVal;
sl@0:     if(odd)
sl@0:         {
sl@0:         mask<<=4;
sl@0:         aValue<<=4;
sl@0:         fatVal=p[0];
sl@0:         fatVal&=~mask;
sl@0:         fatVal|=(TUint8)(aValue&0xFF);
sl@0:         p[0]=fatVal;
sl@0:         p[1]=(TUint8)(aValue>>8);
sl@0:         }
sl@0:     else
sl@0:         {
sl@0:         p[0]=(TUint8)(aValue&0xFF);
sl@0:         fatVal=p[1];
sl@0:         fatVal&=~mask;
sl@0:         fatVal|=(TUint8)(aValue>>8);
sl@0:         p[1]=fatVal;
sl@0:         }
sl@0:     return;
sl@0:     }
sl@0:     
sl@0: 
sl@0: TBool CCheckFatTable::GetNextClusterL(TInt& aCluster) const
sl@0: //
sl@0: // Get the next cluster in the chain from the check fat.
sl@0: //
sl@0:     {
sl@0:     __PRINT(_L("CCheckFatTable::GetNextClusterL"));
sl@0:     TBool ret;
sl@0:     TInt nextCluster=ReadL(aCluster);
sl@0:     if (iOwner->Is16BitFat())
sl@0:         ret=!IsEof16Bit(nextCluster);
sl@0:     else
sl@0:         ret=!IsEof12Bit(nextCluster);
sl@0:     if (ret)
sl@0:         aCluster=nextCluster;
sl@0:     return(ret);
sl@0:     }
sl@0: 
sl@0: void CCheckFatTable::WriteFatEntryEofFL(TInt aCluster)
sl@0: //
sl@0: // Write EOF to aCluster
sl@0: //
sl@0:     {
sl@0:     __PRINT(_L("CCheckFatTable::WriteFatEntryEofF"));
sl@0:     if (iOwner->Is16BitFat())
sl@0:         WriteL(aCluster,EOF_16Bit);
sl@0:     else
sl@0:         WriteL(aCluster,EOF_12Bit);
sl@0:     }
sl@0: 
sl@0: