/*

	FreeRTOS.org V4.1.1 - Copyright (C) 2003-2006 Richard Barry.



	This file is part of the FreeRTOS.org distribution.



	FreeRTOS.org is free software; you can redistribute it and/or modify

	it under the terms of the GNU General Public License as published by

	the Free Software Foundation; either version 2 of the License, or

	(at your option) any later version.



	FreeRTOS.org is distributed in the hope that it will be useful,

	but WITHOUT ANY WARRANTY; without even the implied warranty of

	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

	GNU General Public License for more details.



	You should have received a copy of the GNU General Public License

	along with FreeRTOS.org; if not, write to the Free Software

	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



	A special exception to the GPL can be applied should you wish to distribute

	a combined work that includes FreeRTOS.org, without being obliged to provide

	the source code for any proprietary components.  See the licensing section 

	of http://www.FreeRTOS.org for full details of how and when the exception

	can be applied.



	***************************************************************************

	See http://www.FreeRTOS.org for documentation, latest information, license 

	and contact details.  Please ensure to read the configuration and relevant 

	port sections of the online documentation.

	***************************************************************************

*/



/* 



Changes between V2.5.1 and V2.5.1



	+ The memory pool has been defined within a struct to ensure correct memory

	  alignment on 32bit systems.



Changes between V2.6.1 and V3.0.0



	+ An overflow check has been added to ensure the next free byte variable 

	  does not wrap around.

*/





/*

 * The simplest possible implementation of pvPortMalloc().  Note that this

 * implementation does NOT allow allocated memory to be freed again.

 *

 * See heap_2.c and heap_3.c for alternative implementations, and the memory

 * management pages of http://www.FreeRTOS.org for more information.

 */

#include <stdlib.h>

#include "FreeRTOS.h"

#include "task.h"



/* Setup the correct byte alignment mask for the defined byte alignment. */

#if portBYTE_ALIGNMENT == 4

	#define heapBYTE_ALIGNMENT_MASK	( ( size_t ) 0x0003 )

#endif



#if portBYTE_ALIGNMENT == 2

	#define heapBYTE_ALIGNMENT_MASK	( ( size_t ) 0x0001 )

#endif



#if portBYTE_ALIGNMENT == 1 

	#define heapBYTE_ALIGNMENT_MASK	( ( size_t ) 0x0000 )

#endif



#ifndef heapBYTE_ALIGNMENT_MASK

	#error "Invalid portBYTE_ALIGNMENT definition"

#endif



/* Allocate the memory for the heap.  The struct is used to force byte

alignment without using any non-portable code. */

static struct xRTOS_HEAP

{

	unsigned portLONG ulDummy;

	unsigned portCHAR ucHeap[ configTOTAL_HEAP_SIZE ];

} xHeap;



static size_t xNextFreeByte = ( size_t ) 0;

/*-----------------------------------------------------------*/



void *pvPortMalloc( size_t xWantedSize )

{

void *pvReturn = NULL; 



	/* Ensure that blocks are always aligned to the required number of bytes. */

	#if portBYTE_ALIGNMENT != 1

		if( xWantedSize & heapBYTE_ALIGNMENT_MASK )

		{

			/* Byte alignment required. */

			xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & heapBYTE_ALIGNMENT_MASK ) );

		}

	#endif



	vTaskSuspendAll();

	{

		/* Check there is enough room left for the allocation. */

		if( ( ( xNextFreeByte + xWantedSize ) < configTOTAL_HEAP_SIZE ) &&

			( ( xNextFreeByte + xWantedSize ) > xNextFreeByte )	)/* Check for overflow. */

		{

			/* Return the next free byte then increment the index past this

			block. */

			pvReturn = &( xHeap.ucHeap[ xNextFreeByte ] );

			xNextFreeByte += xWantedSize;			

		}	

	}

	xTaskResumeAll();



	return pvReturn;

}

/*-----------------------------------------------------------*/



void vPortFree( void *pv )

{

	/* Memory cannot be freed using this scheme.  See heap_2.c and heap_3.c 

	for alternative implementations, and the memory management pages of 

	http://www.FreeRTOS.org for more information. */

	( void ) pv;

}

/*-----------------------------------------------------------*/



void vPortInitialiseBlocks( void )

{

	/* Only required when static memory is not cleared. */

	xNextFreeByte = ( size_t ) 0;

}