| 1 | /**
|
|---|
| 2 | ******************************************************************************
|
|---|
| 3 | * @file sysmem.c
|
|---|
| 4 | * @author Generated by STM32CubeMX
|
|---|
| 5 | * @brief System Memory calls file
|
|---|
| 6 | *
|
|---|
| 7 | * For more information about which C functions
|
|---|
| 8 | * need which of these lowlevel functions
|
|---|
| 9 | * please consult the Newlib or Picolibc libc manual
|
|---|
| 10 | ******************************************************************************
|
|---|
| 11 | * @attention
|
|---|
| 12 | *
|
|---|
| 13 | * Copyright (c) 2025 STMicroelectronics.
|
|---|
| 14 | * All rights reserved.
|
|---|
| 15 | *
|
|---|
| 16 | * This software is licensed under terms that can be found in the LICENSE file
|
|---|
| 17 | * in the root directory of this software component.
|
|---|
| 18 | * If no LICENSE file comes with this software, it is provided AS-IS.
|
|---|
| 19 | *
|
|---|
| 20 | ******************************************************************************
|
|---|
| 21 | */
|
|---|
| 22 |
|
|---|
| 23 | /* Includes */
|
|---|
| 24 | #include <errno.h>
|
|---|
| 25 | #include <stdint.h>
|
|---|
| 26 | #include <stddef.h>
|
|---|
| 27 |
|
|---|
| 28 | /**
|
|---|
| 29 | * Pointer to the current high watermark of the heap usage
|
|---|
| 30 | */
|
|---|
| 31 | static uint8_t *__sbrk_heap_end = NULL;
|
|---|
| 32 |
|
|---|
| 33 | /**
|
|---|
| 34 | * @brief _sbrk() allocates memory to the newlib heap and is used by malloc
|
|---|
| 35 | * and others from the C library
|
|---|
| 36 | *
|
|---|
| 37 | * @verbatim
|
|---|
| 38 | * ############################################################################
|
|---|
| 39 | * # .data # .bss # newlib heap # MSP stack #
|
|---|
| 40 | * # # # # Reserved by _Min_Stack_Size #
|
|---|
| 41 | * ############################################################################
|
|---|
| 42 | * ^-- RAM start ^-- _end _estack, RAM end --^
|
|---|
| 43 | * @endverbatim
|
|---|
| 44 | *
|
|---|
| 45 | * This implementation starts allocating at the '_end' linker symbol
|
|---|
| 46 | * The '_Min_Stack_Size' linker symbol reserves a memory for the MSP stack
|
|---|
| 47 | * The implementation considers '_estack' linker symbol to be RAM end
|
|---|
| 48 | * NOTE: If the MSP stack, at any point during execution, grows larger than the
|
|---|
| 49 | * reserved size, please increase the '_Min_Stack_Size'.
|
|---|
| 50 | *
|
|---|
| 51 | * @param incr Memory size
|
|---|
| 52 | * @return Pointer to allocated memory
|
|---|
| 53 | */
|
|---|
| 54 | void *_sbrk(ptrdiff_t incr)
|
|---|
| 55 | {
|
|---|
| 56 | extern uint8_t _end; /* Symbol defined in the linker script */
|
|---|
| 57 | extern uint8_t _estack; /* Symbol defined in the linker script */
|
|---|
| 58 | extern uint32_t _Min_Stack_Size; /* Symbol defined in the linker script */
|
|---|
| 59 | const uint32_t stack_limit = (uint32_t)&_estack - (uint32_t)&_Min_Stack_Size;
|
|---|
| 60 | const uint8_t *max_heap = (uint8_t *)stack_limit;
|
|---|
| 61 | uint8_t *prev_heap_end;
|
|---|
| 62 |
|
|---|
| 63 | /* Initialize heap end at first call */
|
|---|
| 64 | if (NULL == __sbrk_heap_end)
|
|---|
| 65 | {
|
|---|
| 66 | __sbrk_heap_end = &_end;
|
|---|
| 67 | }
|
|---|
| 68 |
|
|---|
| 69 | /* Protect heap from growing into the reserved MSP stack */
|
|---|
| 70 | if (__sbrk_heap_end + incr > max_heap)
|
|---|
| 71 | {
|
|---|
| 72 | errno = ENOMEM;
|
|---|
| 73 | return (void *)-1;
|
|---|
| 74 | }
|
|---|
| 75 |
|
|---|
| 76 | prev_heap_end = __sbrk_heap_end;
|
|---|
| 77 | __sbrk_heap_end += incr;
|
|---|
| 78 |
|
|---|
| 79 | return (void *)prev_heap_end;
|
|---|
| 80 | }
|
|---|
| 81 |
|
|---|
| 82 | #if defined(__PICOLIBC__)
|
|---|
| 83 | // Picolibc expects syscalls without the leading underscore.
|
|---|
| 84 | // This creates a strong alias so that
|
|---|
| 85 | // calls to `sbrk()` are resolved to our `_sbrk()` implementation.
|
|---|
| 86 | __strong_reference(_sbrk, sbrk);
|
|---|
| 87 | #endif
|
|---|
