kernel/eka/include/memmodel/epoc/mmubase/kblockmap.h
author Tom Cosgrove <tom.cosgrove@nokia.com>
Fri, 28 May 2010 16:29:07 +0100
changeset 30 8aab599e3476
parent 6 0173bcd7697c
permissions -rw-r--r--
Fix for bug 2283 (RVCT 4.0 support is missing from PDK 3.0.h) Have multiple extension sections in the bld.inf, one for each version of the compiler. The RVCT version building the tools will build the runtime libraries for its version, but make sure we extract all the other versions from zip archives. Also add the archive for RVCT4.

// 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:
// e32\include\memmodel\epoc\mmubase\kblockmap.h
// Kernel-side functionality for processing block maps
// 
// WARNING: This file contains some APIs which are internal and are subject
//          to change without notice. Such APIs should therefore not be used
//          outside the Kernel and Hardware Services package.
//

#ifndef __KBLOCKMAP_H__
#define __KBLOCKMAP_H__

#include <e32ldr.h>
#include <e32ldr_private.h>

/**
The kernel-side representation of a block map.
*/
class TBlockMap
	{
public:
	TBlockMap();
	~TBlockMap();
	
	/**
	Initialise and populate kernel-side representation from a user-side block map

	@param aBlockMapInfo    	The user-side block map info structure.
	
	@param aBlockMapEntries 	Pointer to a buffer containg the user-side block map entries.
	                            This object takes ownership of the buffer.
	                        
	@param aBlockMapEntriesSize The size of the user-side block map entries in bytes.

	@param aReadUnitShift       Log2 of the paging device's read unit size.
	
	@param aDataLengthInFile 	The length of the (possibly compressed) code in the file.
	*/
	TInt Initialise(const SBlockMapInfoBase& aBlockMapInfo,
					TBlockMapEntryBase* aBlockMapEntries,
                    TInt aBlockMapEntriesSize,
					TInt aReadUnitShift,
					TInt aDataLengthInFile);

	/**
	A function supplied to Read that is called to read the actual data.
	
	@param aArg1   		An argument parameter passed to read.
	@param aArg2   		Another argument parameter passed to read.
	@param aBuffer 		The address of the buffer to read the data into.
	@param aBlockNumber The block number to read.
	@param aBlockCount 	The number of blocks to read.
	*/
	typedef TInt (*TReadFunc)(TAny* aArg1, TAny* aArg2, TLinAddr aBuffer, TInt aBlockNumber, TInt aBlockCount);

	/**
	Read data from the file described by the block map into a buffer.

	@param aBuffer   	  The buffer into which to read the data.
	@param aPos	   	 	  The offset from the start of the data at which to read.
	@param aLength   	  The length of data to read in bytes.
	@param aReadUnitShift Log2 of the paging device's read unit size.
	@param aReadFunc 	  The function to call to read the blocks of data.
	@param aArg1   		  An argument parameter passed to read.
	@param aArg2   		  Another argument parameter passed to read.
	
	@return The offset into the buffer at which the data starts, or one of the system-wide error
	codes.
	*/
	TInt Read(TLinAddr aBuffer, TInt aPos, TInt aLength, TInt aReadUnitShift, TReadFunc aReadFunc, TAny* aArg1, TAny* aArg2) const;

	/**
	A contiguous area of media containing (possibly compressed) code.
	*/
	struct SExtent
		{
		TInt iDataOffset;		// position in file from, counting from start of code data
		TUint iBlockNumber;		// block number containg this position
		};

	inline TInt Count() const;
	inline const SExtent& Extent(TInt aIndex) const;
	inline TInt DataLength() const;

	/**
	Print out the contents of this object for debugging purposes.
	This method is only implemented in debug builds.
	*/
	void Dump() const;

private:
	
	TInt FindFirstExtent(TInt aPos) const;

private:

	TInt iDataLength;
	TInt iExtentCount;
	SExtent* iExtents;
	};

inline TInt TBlockMap::Count() const
	{
	return iExtentCount;
	}

inline const TBlockMap::SExtent& TBlockMap::Extent(TInt aIndex) const
	{
	return iExtents[aIndex];
	}

inline TInt TBlockMap::DataLength() const
	{
	return iDataLength;
	}

#endif