void * say_hello(void *arg) { struct sched_param p; p . sched_priority = 1; pthread_setschedparam (pthread_self(), SCHED_FIFO, &p); pthread_make_periodic_np (pthread_self(), gethrtime(), 500000000); while (1) { pthread_wait_np (); rtl_printf("I'm here; my arg is %x\n", (unsigned) arg); } return 0; }