80 lines
2.8 KiB
C
80 lines
2.8 KiB
C
/**
|
|
******************************************************************************
|
|
* @file sysmem.c
|
|
* @author Generated by STM32CubeIDE
|
|
* @brief STM32CubeIDE System Memory calls file
|
|
*
|
|
* For more information about which C functions
|
|
* need which of these lowlevel functions
|
|
* please consult the newlib libc manual
|
|
******************************************************************************
|
|
* @attention
|
|
*
|
|
* <h2><center>© Copyright (c) 2020 STMicroelectronics.
|
|
* All rights reserved.</center></h2>
|
|
*
|
|
* This software component is licensed by ST under BSD 3-Clause license,
|
|
* the "License"; You may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at:
|
|
* opensource.org/licenses/BSD-3-Clause
|
|
*
|
|
******************************************************************************
|
|
*/
|
|
|
|
/* Includes */
|
|
#include <errno.h>
|
|
#include <stdint.h>
|
|
|
|
/**
|
|
* Pointer to the current high watermark of the heap usage
|
|
*/
|
|
static uint8_t *__sbrk_heap_end = NULL;
|
|
|
|
/**
|
|
* @brief _sbrk() allocates memory to the newlib heap and is used by malloc
|
|
* and others from the C library
|
|
*
|
|
* @verbatim
|
|
* ############################################################################
|
|
* # .data # .bss # newlib heap # MSP stack #
|
|
* # # # # Reserved by _Min_Stack_Size #
|
|
* ############################################################################
|
|
* ^-- RAM start ^-- _end _estack, RAM end --^
|
|
* @endverbatim
|
|
*
|
|
* This implementation starts allocating at the '_end' linker symbol
|
|
* The '_Min_Stack_Size' linker symbol reserves a memory for the MSP stack
|
|
* The implementation considers '_estack' linker symbol to be RAM end
|
|
* NOTE: If the MSP stack, at any point during execution, grows larger than the
|
|
* reserved size, please increase the '_Min_Stack_Size'.
|
|
*
|
|
* @param incr Memory size
|
|
* @return Pointer to allocated memory
|
|
*/
|
|
void *_sbrk(ptrdiff_t incr)
|
|
{
|
|
extern uint8_t _end; /* Symbol defined in the linker script */
|
|
extern uint8_t _estack; /* Symbol defined in the linker script */
|
|
extern uint32_t _Min_Stack_Size; /* Symbol defined in the linker script */
|
|
const uint32_t stack_limit = (uint32_t)&_estack - (uint32_t)&_Min_Stack_Size;
|
|
const uint8_t *max_heap = (uint8_t *)stack_limit;
|
|
uint8_t *prev_heap_end;
|
|
|
|
/* Initialize heap end at first call */
|
|
if (NULL == __sbrk_heap_end)
|
|
{
|
|
__sbrk_heap_end = &_end;
|
|
}
|
|
|
|
/* Protect heap from growing into the reserved MSP stack */
|
|
if (__sbrk_heap_end + incr > max_heap)
|
|
{
|
|
errno = ENOMEM;
|
|
return (void *)-1;
|
|
}
|
|
|
|
prev_heap_end = __sbrk_heap_end;
|
|
__sbrk_heap_end += incr;
|
|
|
|
return (void *)prev_heap_end;
|
|
}
|