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Diffstat (limited to 'GameLogic/stm32/sysmem.c')
-rw-r--r-- | GameLogic/stm32/sysmem.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/GameLogic/stm32/sysmem.c b/GameLogic/stm32/sysmem.c new file mode 100644 index 0000000..54081ac --- /dev/null +++ b/GameLogic/stm32/sysmem.c @@ -0,0 +1,79 @@ +/** + ****************************************************************************** + * @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 + * + * Copyright (c) 2022 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 <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; +} |