/*

* Copyright (c) 2006-2009 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: 

* This class represents the boot sector of a FAT16 image. 

* This class is derived from basebootsector class which is constitutes 

* the common boot sector fields for FAT16 and FAT32 class. 	

* @internalComponent

* @released

*

*/

#include "fat16bootsector.h"

#include <cstring>

/**

Constructor of the fat16 boot sector class

@internalComponent

@released

*/

TFAT16BootSector::TFAT16BootSector()

{

}

/**

Destructor of the fat16 boot sector class

@internalComponent

@released

*/

TFAT16BootSector::~TFAT16BootSector()

{

}

/**

Set the file system type

@internalComponent

@released

*/

void TFAT16BootSector::SetFileSysType()

{

	strcpy(reinterpret_cast<char*>(iFileSysType),"FAT16   ");

}	

/**

returns the file system type

@return file system type 

@internalComponent

@released

*/

unsigned char* TFAT16BootSector::FileSysType()

{

	return iFileSysType;

}

/**

Number of entries allowed in the root directory,specific to Fat12/16,

zero for FAT32

@internalComponent

@released

*/

void TFAT16BootSector::SetRootDirEntries()

{

	iRootDirEntries = KDefaultRootDirEntries;;		

}

/**

Sets the number of reserved sectors on the volume

@internalComponent

@released

*/

void TFAT16BootSector::SetReservedSectors()

{

	iReservedSectors = KDefaultFat16ReservedSectors;

}

/**

Computes the sectors per cluster ratio

To refer this mathematical computation, Please see:

Microsoft Extensible Firmware Initiative FAT32 File 

System Specification document

@internalComponent

@released

@param aPartitionSize partition size in bytes

*/

void TFAT16BootSector::ComputeSectorsPerCluster(Long64 aPartitionSize)

{

	if(aPartitionSize > K1GB)

	{

		iSectorsPerCluster = K64SectorsPerCluster;

	}

	else if(aPartitionSize > K512MB)

	{

		iSectorsPerCluster = K32SectorsPerCluster;

	}

	else if(aPartitionSize > K256MB)

	{

		iSectorsPerCluster = K16SectorsPerCluster;

	}

	else if(aPartitionSize > K128MB)

	{

		iSectorsPerCluster = K8SectorsPerCluster;

	}

	else if(aPartitionSize > K16MB)

	{

		iSectorsPerCluster = K4SectorsPerCluster;

	}

	else 

	{

		iSectorsPerCluster = K2SectorsPerCluster;

	}

}

/**

Sectors used for the Fat table

To refer this mathematical formulae, Please see:

Microsoft Extensible Firmware Initiative FAT32 File System Specification 

document

@internalComponent

@released

@param aPartitionSize partition size

*/

void TFAT16BootSector::ComputeFatSectors(Long64 aPartitionSize)

{

	int iRootDirSectors = ((iRootDirEntries * 32) + (iBytesPerSector - 1)) / iBytesPerSector;

	int Log2OfBytesPerSector = Log2(iBytesPerSector);

	unsigned long TotalSectors64 = (unsigned long)(aPartitionSize >> Log2OfBytesPerSector);

	unsigned int tmpval1 = TotalSectors64 - (iReservedSectors + iRootDirSectors);

	unsigned int tmpval2 =(256 * iSectorsPerCluster) + iNumberOfFats;

	unsigned int FatSectors =(tmpval1 + (tmpval2 - 1)) / tmpval2;

	iFatSectors = (unsigned short)FatSectors;	

	iFatSectors32 = 0;

}