Question
Why is a fresh FreeRTOS project using all my RAM? How can I determine the root cause?
Hi, see above. I am using a custom G030F6 breakout board with the intent to install FreeRTOS and use this small device as a learning exercise as I usually use larger MCUs and super loops. My first hurdle is my RAM usage with a blank, generated projected. I get the following error when I configure FreeRTOS using STM32CubeIDE (I also get the same error if i import freertos manually and use the same memory allocations) and then compile a brand new project:
section `._user_heap_stack' will not fit in region `RAM'
I understand this to mean that my memory allocations are too large to fit within the available RAM. My chosen device has RAM of 8KB. My config is as follows:
#ifndef FREERTOS_CONFIG_H
#define FREERTOS_CONFIG_H
/*-----------------------------------------------------------
* Application specific definitions.
*
* These definitions should be adjusted for your particular hardware and
* application requirements.
*
* These parameters and more are described within the 'configuration' section of the
* FreeRTOS API documentation available on the FreeRTOS.org web site.
*
* See http://www.freertos.org/a00110.html
*----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* Section where include file can be added */
/* USER CODE END Includes */
/* Ensure definitions are only used by the compiler, and not by the assembler. */
#if defined(__ICCARM__) || defined(__CC_ARM) || defined(__GNUC__)
#include <stdint.h>
extern uint32_t SystemCoreClock;
#endif
#ifndef CMSIS_device_header
#define CMSIS_device_header "stm32g0xx.h"
#endif /* CMSIS_device_header */
#define configENABLE_FPU 0
#define configENABLE_MPU 0
#define configUSE_PREEMPTION 1
#define configSUPPORT_STATIC_ALLOCATION 1
#define configSUPPORT_DYNAMIC_ALLOCATION 1
#define configUSE_IDLE_HOOK 0
#define configUSE_TICK_HOOK 0
#define configCPU_CLOCK_HZ ( SystemCoreClock )
#define configTICK_RATE_HZ ((TickType_t)1000)
#define configMAX_PRIORITIES ( 56 )
#define configMINIMAL_STACK_SIZE ((uint16_t)128)
#define configTOTAL_HEAP_SIZE ((size_t)3072)
#define configMAX_TASK_NAME_LEN ( 16 )
#define configUSE_TRACE_FACILITY 1
#define configUSE_16_BIT_TICKS 0
#define configUSE_MUTEXES 1
#define configQUEUE_REGISTRY_SIZE 8
#define configUSE_RECURSIVE_MUTEXES 1
#define configUSE_COUNTING_SEMAPHORES 1
#define configUSE_PORT_OPTIMISED_TASK_SELECTION 0
/* USER CODE BEGIN MESSAGE_BUFFER_LENGTH_TYPE */
/* Defaults to size_t for backward compatibility, but can be changed
if lengths will always be less than the number of bytes in a size_t. */
#define configMESSAGE_BUFFER_LENGTH_TYPE size_t
/* USER CODE END MESSAGE_BUFFER_LENGTH_TYPE */
/* Co-routine definitions. */
#define configUSE_CO_ROUTINES 0
#define configMAX_CO_ROUTINE_PRIORITIES ( 2 )
/* Software timer definitions. */
#define configUSE_TIMERS 1
#define configTIMER_TASK_PRIORITY ( 2 )
#define configTIMER_QUEUE_LENGTH 10
#define configTIMER_TASK_STACK_DEPTH 256
/* The following flag must be enabled only when using newlib */
#define configUSE_NEWLIB_REENTRANT 1
/* CMSIS-RTOS V2 flags */
#define configUSE_OS2_THREAD_SUSPEND_RESUME 1
#define configUSE_OS2_THREAD_ENUMERATE 1
#define configUSE_OS2_EVENTFLAGS_FROM_ISR 1
#define configUSE_OS2_THREAD_FLAGS 1
#define configUSE_OS2_TIMER 1
#define configUSE_OS2_MUTEX 1
/* Set the following definitions to 1 to include the API function, or zero
to exclude the API function. */
#define INCLUDE_vTaskPrioritySet 1
#define INCLUDE_uxTaskPriorityGet 1
#define INCLUDE_vTaskDelete 1
#define INCLUDE_vTaskCleanUpResources 0
#define INCLUDE_vTaskSuspend 1
#define INCLUDE_vTaskDelayUntil 1
#define INCLUDE_vTaskDelay 1
#define INCLUDE_xTaskGetSchedulerState 1
#define INCLUDE_xTimerPendFunctionCall 1
#define INCLUDE_xQueueGetMutexHolder 1
#define INCLUDE_uxTaskGetStackHighWaterMark 1
#define INCLUDE_xTaskGetCurrentTaskHandle 1
#define INCLUDE_eTaskGetState 1
/*
* The CMSIS-RTOS V2 FreeRTOS wrapper is dependent on the heap implementation used
* by the application thus the correct define need to be enabled below
*/
#define USE_FreeRTOS_HEAP_4
/* Normal assert() semantics without relying on the provision of an assert.h
header file. */
/* USER CODE BEGIN 1 */
#define configASSERT( x ) if ((x) == 0) {taskDISABLE_INTERRUPTS(); for( ;; );}
/* USER CODE END 1 */
/* Definitions that map the FreeRTOS port interrupt handlers to their CMSIS
standard names. */
#define vPortSVCHandler SVC_Handler
#define xPortPendSVHandler PendSV_Handler
/* IMPORTANT: After 10.3.1 update, Systick_Handler comes from NVIC (if SYS timebase = systick), otherwise from cmsis_os2.c */
#define USE_CUSTOM_SYSTICK_HANDLER_IMPLEMENTATION 0
/* USER CODE BEGIN Defines */
/* Section where parameter definitions can be added (for instance, to override default ones in FreeRTOS.h) */
/* USER CODE END Defines */
#endif /* FREERTOS_CONFIG_H */
If my heap is 3KB and stack is configured to be 256 Bytes, where is the other 5KB being used?
thanks in advance.
Edit: reducing heap size to 2KB resulted in a successful compilation, but I still want to know what the original cause is. Where is my RAM being used. Fully compiled blank project attached. Thanks all.