141 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*----------------------------------------------------------------------------
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|  *      RL-ARM - RTX
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|  *----------------------------------------------------------------------------
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|  *      Name:    RT_MEMORY.C
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|  *      Purpose: Interface functions for Dynamic Memory Management System
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|  *      Rev.:    V4.70
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|  *----------------------------------------------------------------------------
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|  *
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|  * Copyright (c) 1999-2009 KEIL, 2009-2013 ARM Germany GmbH
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|  * All rights reserved.
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions are met:
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|  *  - Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  *  - Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  *  - Neither the name of ARM  nor the names of its contributors may be used 
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|  *    to endorse or promote products derived from this software without 
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|  *    specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
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|  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
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|  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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|  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
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|  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
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|  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
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|  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
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|  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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|  * POSSIBILITY OF SUCH DAMAGE.
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|  *---------------------------------------------------------------------------*/
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| 
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| #include "rt_TypeDef.h"
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| #include "rt_Memory.h"
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| 
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| 
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| /* Functions */
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| 
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| // Initialize Dynamic Memory pool
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| //   Parameters:
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| //     pool:    Pointer to memory pool
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| //     size:    Size of memory pool in bytes
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| //   Return:    0 - OK, 1 - Error
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| 
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| int rt_init_mem (void *pool, U32 size) {
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|   MEMP *ptr;
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| 
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|   if ((pool == NULL) || (size < sizeof(MEMP))) return (1);
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| 
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|   ptr = (MEMP *)pool;
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|   ptr->next = (MEMP *)((U32)pool + size - sizeof(MEMP *));
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|   ptr->next->next = NULL;
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|   ptr->len = 0; 
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| 
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|   return (0);
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| }
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| 
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| // Allocate Memory from Memory pool
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| //   Parameters:
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| //     pool:    Pointer to memory pool
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| //     size:    Size of memory in bytes to allocate
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| //   Return:    Pointer to allocated memory
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| 
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| void *rt_alloc_mem (void *pool, U32 size) {
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|   MEMP *p, *p_search, *p_new;
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|   U32   hole_size;
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| 
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|   if ((pool == NULL) || (size == 0)) return NULL;
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| 
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|   /* Add header offset to 'size' */
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|   size += sizeof(MEMP);
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|   /* Make sure that block is 4-byte aligned  */
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|   size = (size + 3) & ~3;
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| 
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|   p_search = (MEMP *)pool;
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|   while (1) {
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|     hole_size  = (U32)p_search->next - (U32)p_search;
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|     hole_size -= p_search->len;
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|     /* Check if hole size is big enough */
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|     if (hole_size >= size) break;
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|     p_search = p_search->next;
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|     if (p_search->next == NULL) {
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|       /* Failed, we are at the end of the list */
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|       return NULL;
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|     }
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|   }
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| 
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|   if (p_search->len == 0) {
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|     /* No block is allocated, set the Length of the first element */
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|     p_search->len = size;
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|     p = (MEMP *)(((U32)p_search) + sizeof(MEMP));
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|   } else {
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|     /* Insert new list element into the memory list */
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|     p_new       = (MEMP *)((U32)p_search + p_search->len);
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|     p_new->next = p_search->next;
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|     p_new->len  = size;
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|     p_search->next = p_new;
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|     p = (MEMP *)(((U32)p_new) + sizeof(MEMP));
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|   }
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| 
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|   return (p);
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| }
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| 
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| // Free Memory and return it to Memory pool
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| //   Parameters:
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| //     pool:    Pointer to memory pool
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| //     mem:     Pointer to memory to free
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| //   Return:    0 - OK, 1 - Error
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| 
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| int rt_free_mem (void *pool, void *mem) {
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|   MEMP *p_search, *p_prev, *p_return;
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| 
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|   if ((pool == NULL) || (mem == NULL)) return (1);
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| 
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|   p_return = (MEMP *)((U32)mem - sizeof(MEMP));
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|   
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|   /* Set list header */
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|   p_prev = NULL;
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|   p_search = (MEMP *)pool;
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|   while (p_search != p_return) {
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|     p_prev   = p_search;
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|     p_search = p_search->next;
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|     if (p_search == NULL) {
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|       /* Valid Memory block not found */
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|       return (1);
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|     }
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|   }
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| 
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|   if (p_prev == NULL) {
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|     /* First block to be released, only set length to 0 */
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|     p_search->len = 0;
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|   } else {
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|     /* Discard block from chain list */
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|     p_prev->next = p_search->next;
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|   }
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| 
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|   return (0);
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| }
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