Hi Andrej,

The idea of the OS wrapper layer is to abstract the underlying OS, so that the test app can use generic wrapper APIs, which are implemented using OS-specific APIs. In os_wrapper_rtx.c, we provide an example implementation that targets the CMSIS-RTOS2 APIs for RTX.

As osThreadJoinable is not supported by FreeRTOS, you can remove that attribute in your port, and implement os_wrapper_join_thread() as a no-op. We use semaphores for synchronisation in the test app anyway, so os_wrapper_join_thread() only needs to be implemented if threads are joinable and so need join() to be called to free up resources associated with the thread.

I do think we could make the OS wrapper layer a bit more generic though. We could replace the only call to os_wrapper_join_thread() that currently exists with a call to a new function os_wrapper_delete_thread(), which is defined to release the resources associated with a thread context. For CMSIS-RTOS2 this can be empty because this happens automatically, but for other RTOS APIs there may be some delete() function that needs to be called. Let me know what you think.

Best wishes, Jamie

-----Original Message----- From: TF-M tf-m-bounces@lists.trustedfirmware.org On Behalf Of Andrej Butok via TF-M Sent: 02 May 2019 15:04 To: tf-m@lists.trustedfirmware.org Subject: [TF-M] Avoid osThreadJoin()

Hello,

The TFM test applications are using CMSIS-RTOS2 API. And this is good. But could you delete os_wrapper_join_thread()and avoid using of osThreadJoin(). If I understand well, its support by RTOS tasks is optional (via osThreadJoinable flag).

The problem is that the osThreadJoin() functionality is not supported by FreeRTOS (https://arm-software.github.io/CMSIS-FreeRTOS/General/html/tech_data.html). It is critical obstacle.

Could you tell what are you going to do with this requirement? To understand, if to continue with a FreeRTOS port.

Thank you Andrej Butok