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/*
FreeRTOS.org V4.2.1 - Copyright (C) 2003-2007 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.
Also see http://www.SafeRTOS.com for an IEC 61508 compliant version along
with commercial development and support options.
***************************************************************************
*/
/*
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 == 8
#define heapBYTE_ALIGNMENT_MASK ( ( size_t ) 0x0007 )
#endif
#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;
}
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