2 FreeRTOS.org V5.3.1 - Copyright (C) 2003-2009 Richard Barry.
\r
4 This file is part of the FreeRTOS.org distribution.
\r
6 FreeRTOS.org is free software; you can redistribute it and/or modify it
\r
7 under the terms of the GNU General Public License (version 2) as published
\r
8 by the Free Software Foundation and modified by the FreeRTOS exception.
\r
9 **NOTE** The exception to the GPL is included to allow you to distribute a
\r
10 combined work that includes FreeRTOS.org without being obliged to provide
\r
11 the source code for any proprietary components. Alternative commercial
\r
12 license and support terms are also available upon request. See the
\r
13 licensing section of http://www.FreeRTOS.org for full details.
\r
15 FreeRTOS.org is distributed in the hope that it will be useful, but WITHOUT
\r
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
\r
17 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
20 You should have received a copy of the GNU General Public License along
\r
21 with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59
\r
22 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
\r
25 ***************************************************************************
\r
27 * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
\r
29 * This is a concise, step by step, 'hands on' guide that describes both *
\r
30 * general multitasking concepts and FreeRTOS specifics. It presents and *
\r
31 * explains numerous examples that are written using the FreeRTOS API. *
\r
32 * Full source code for all the examples is provided in an accompanying *
\r
35 ***************************************************************************
\r
39 Please ensure to read the configuration and relevant port sections of the
\r
40 online documentation.
\r
42 http://www.FreeRTOS.org - Documentation, latest information, license and
\r
45 http://www.SafeRTOS.com - A version that is certified for use in safety
\r
48 http://www.OpenRTOS.com - Commercial support, development, porting,
\r
49 licensing and training services.
\r
54 Changes between V2.5.1 and V2.5.1
\r
56 + The memory pool has been defined within a struct to ensure correct memory
\r
57 alignment on 32bit systems.
\r
59 Changes between V2.6.1 and V3.0.0
\r
61 + An overflow check has been added to ensure the next free byte variable
\r
62 does not wrap around.
\r
67 * The simplest possible implementation of pvPortMalloc(). Note that this
\r
68 * implementation does NOT allow allocated memory to be freed again.
\r
70 * See heap_2.c and heap_3.c for alternative implementations, and the memory
\r
71 * management pages of http://www.FreeRTOS.org for more information.
\r
74 #include "FreeRTOS.h"
\r
77 /* Setup the correct byte alignment mask for the defined byte alignment. */
\r
79 #if portBYTE_ALIGNMENT == 8
\r
80 #define heapBYTE_ALIGNMENT_MASK ( ( size_t ) 0x0007 )
\r
83 #if portBYTE_ALIGNMENT == 4
\r
84 #define heapBYTE_ALIGNMENT_MASK ( ( size_t ) 0x0003 )
\r
87 #if portBYTE_ALIGNMENT == 2
\r
88 #define heapBYTE_ALIGNMENT_MASK ( ( size_t ) 0x0001 )
\r
91 #if portBYTE_ALIGNMENT == 1
\r
92 #define heapBYTE_ALIGNMENT_MASK ( ( size_t ) 0x0000 )
\r
95 #ifndef heapBYTE_ALIGNMENT_MASK
\r
96 #error "Invalid portBYTE_ALIGNMENT definition"
\r
99 /* Allocate the memory for the heap. The struct is used to force byte
\r
100 alignment without using any non-portable code. */
\r
101 static union xRTOS_HEAP
\r
103 volatile unsigned portLONG ulDummy;
\r
104 unsigned portCHAR ucHeap[ configTOTAL_HEAP_SIZE ];
\r
107 static size_t xNextFreeByte = ( size_t ) 0;
\r
108 /*-----------------------------------------------------------*/
\r
110 void *pvPortMalloc( size_t xWantedSize )
\r
112 void *pvReturn = NULL;
\r
114 /* Ensure that blocks are always aligned to the required number of bytes. */
\r
115 #if portBYTE_ALIGNMENT != 1
\r
116 if( xWantedSize & heapBYTE_ALIGNMENT_MASK )
\r
118 /* Byte alignment required. */
\r
119 xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & heapBYTE_ALIGNMENT_MASK ) );
\r
125 /* Check there is enough room left for the allocation. */
\r
126 if( ( ( xNextFreeByte + xWantedSize ) < configTOTAL_HEAP_SIZE ) &&
\r
127 ( ( xNextFreeByte + xWantedSize ) > xNextFreeByte ) )/* Check for overflow. */
\r
129 /* Return the next free byte then increment the index past this
\r
131 pvReturn = &( xHeap.ucHeap[ xNextFreeByte ] );
\r
132 xNextFreeByte += xWantedSize;
\r
139 /*-----------------------------------------------------------*/
\r
141 void vPortFree( void *pv )
\r
143 /* Memory cannot be freed using this scheme. See heap_2.c and heap_3.c
\r
144 for alternative implementations, and the memory management pages of
\r
145 http://www.FreeRTOS.org for more information. */
\r
148 /*-----------------------------------------------------------*/
\r
150 void vPortInitialiseBlocks( void )
\r
152 /* Only required when static memory is not cleared. */
\r
153 xNextFreeByte = ( size_t ) 0;
\r