Hello fat16lib. Right now I am porting CAN protocol in Due. To test transmission (receiving messages) I am using a couple of interrupt handlers that read CAN controllers addresses at 0x400000000 in the memory-mapped interrupts of the CORTEX-M3. After a message is received, some I/O are managed. Like you said, a couple of calls to weak (aliases) dummy functions were enough. All these with third-party CMSIS gnu gcc exceptions. Regarding your RTOS hooks, I believe they could add more value for Due but from what I understand, as the more we are attached to the Arduino IDE libraries, the better for the Arduino community. Some 'exceptions' may apply. Regards.