Add FreeRTOS Manually in an STM32 Project. In this project, Ihave used an STM32F401 discovery board. Here are the steps that you can follow

1. Open cube Mx and Generate a basic project with two LEDs as output.
2. Download Free RTOS from the website "https://www.freertos.org/a00104.html"
3. Extract the downloaded Zip and copy "FreeRTOS/source" folder in to your stm32 project.
4. In the copied source folder, there is a portable folder. Delete all the file accept these two.

5. Open source/poratble/GCC folder and delete all the folders inside it accept the one shown in the image

6. Open source/poratble/MemMang and delete all the files accept "heap_4.c".

7. In the downloaded FreeRTOS folder there is a folder called "Demo", open this and find "CORTEX_M4F_STM32F407ZG-SK" folder, there is a "FreeRTOSConfig.h" file inside it. Copy this file into inc folder of your stm32 project.

8. make changes in "FreeRTOSConfig.h" as per the image below

9. create "rtos_config.c" in to your project and add below code inside it.

   #include "FreeRTOS.h" #include "task.h"

void vApplicationGetIdleTaskMemory(StaticTask_t **ppxIdleTaskTCBBuffer, StackType_t **ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize) { static StaticTask_t xIdleTaskTCB; static StackType_t uxIdleTaskStack[configMINIMAL_STACK_SIZE];

*ppxIdleTaskTCBBuffer = &xIdleTaskTCB;
*ppxIdleTaskStackBuffer = uxIdleTaskStack;
*pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;

}

void vApplicationGetTimerTaskMemory(StaticTask_t **ppxTimerTaskTCBBuffer, StackType_t **ppxTimerTaskStackBuffer, uint32_t *pulTimerTaskStackSize) { static StaticTask_t xTimerTaskTCB; static StackType_t uxTimerTaskStack[configTIMER_TASK_STACK_DEPTH];

*ppxTimerTaskTCBBuffer = &xTimerTaskTCB;
*ppxTimerTaskStackBuffer = uxTimerTaskStack;
*pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;

}

10. Now FREE Rtos a is ready. create two tasks in main.c and toggle leds in both of them with 500ms delay.