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/**
******************************************************************************
* @file k_mem.c
* @author MCD Application Team
* @brief Utilities for file handling
******************************************************************************
* @attention
*
* Copyright (c) 2017 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "k_mem.h"
/** @addtogroup CORE
* @{
*/
/** @defgroup KERNEL_MEMORY
* @brief Kernel memory routines
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define MEM_BASE 0x10000000
/* Private macro -------------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
#if (defined ( __CC_ARM ))
mem_TypeDef memory_pool __attribute__((at(MEM_BASE)));
#elif (defined (__ICCARM__))
#pragma location = MEM_BASE
__no_init mem_TypeDef memory_pool;
#elif defined ( __GNUC__ )
mem_TypeDef memory_pool __attribute__((section(".ExtRAMData")));
#endif
/* Private functions ---------------------------------------------------------*/
/**
* @brief This function Initialize a memory pool for private allocator.
* @param None
* @retval None
*/
void k_MemInit(void)
{
memset(&memory_pool, 0, sizeof(mem_TypeDef));
memory_pool.mallocBase = MEM_BASE + sizeof(mem_TypeDef);
}
/**
* @brief This function implement a simple memory management algorithm (First fit).
* @param size : Requested memory size.
* @retval Pointer to the allocated region.
*/
void * k_malloc(size_t size)
{
__IO uint8_t index = 0, counter = 0, start = 0;
uint8_t PageCount = 0, NewStart = 0;
if (size > 0)
{
/* look for the first contiguous memory that meet requested size. */
while ( index < (MAX_PAGE_NUMBER))
{
if (memory_pool.PageTable[index++] == 0)
{
counter++;
if (size <= (counter * SIZE_OF_PAGE))
{
PageCount = counter - 1;
NewStart = start;
/* Set memory region state to allocated */
for (index = 0; index <= PageCount;index++)
{
memory_pool.PageTable[NewStart + index] = 1;
}
/* Save size */
memory_pool.size[NewStart] = counter;
/* return pointer to allocated region. */
return (void *)((memory_pool.mallocBase + (start << 10)) + 1 * sizeof(uint32_t));
}
}
else
{
start = index;
counter = 0;
}
}
}
return NULL;
}
/**
* @brief Free previously allocated memory
* @param Pointer to the allocated region.
* @retval None
*/
void k_free(void * p)
{
__IO uint8_t index = 0;
uint8_t counter = 0, start = 0;
/* Handle NULL pointers */
if (p == NULL)
return;
/* Find start Index */
start = ((((uint32_t)p - sizeof(uint32_t)) - memory_pool.mallocBase) >> 10);
/* Retrieve segment size */
counter = memory_pool.size[start];
/* Set size to zero */
memory_pool.size[start] = 0;
/* Deallocate memory region */
for (index = 0; index < counter; index++)
{
memory_pool.PageTable[start + index] = 0;
}
return;
}
/**
* @}
*/
/**
* @}
*/