Background, We have projects where the SYS timebase is set to a peripheral timer. Currently, this no longer works with the new cubeMX version.
In STM32CubeIDE 1.17, migrating projects to the updated CubeMX version (6.12.0 -> 6.13.0) modifies the FreeRTOSConfig.h file in Core/Inc. Specifically, the following changes occur:
Old lines (140–143):
/* IMPORTANT: This define is commented when used with STM32Cube firmware, when the timebase source is SysTick, to prevent overwriting SysTick_Handler defined within STM32Cube HAL */
#define xPortSysTickHandler SysTick_Handler
New lines (144–146):
/* 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
The old configuration ensured that FreeRTOS used its SysTick implementation from port.c. Specifically, xPortSysTickHandler in port.c was renamed to SysTick_Handler, matching the function name in the startup file's interrupt vector.
With the new configuration, this renaming no longer happens. If the SYS timebase is configured to use a timer peripheral (instead of SysTick), there is no implementation of the SysTick_Handler function, leaving the interrupt unhandled. As a result, the Default_Handler is used, which prevents FreeRTOS from switching tasks.
If the SYS timebase is configured to use SysTick in the .ioc file, an implementation of SysTick_Handler is generated in stm32f3xx_it.c. This generated function calls both HAL_IncTick and xPortSysTickHandler. This indicates that ST assumes the SYS timebase is always set to SysTick and that the use of a timer peripheral as the SYS timebase is no longer supported.
Effectively, FreeRTOS no longer works when using a timer peripheral as the SYS timebase in STM32CubeIDE 1.17 after migrating the project.
