Instead of looking for new system calls, why not just solve this problem at the application level? 1. boot machine 2. start ptp4l 3. wait five seconds 4. start control app, and just use clock_realtime HTH, Richard -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html