timerfd_settime

timers that notify via file descriptors

sys_timerfd_settime(int ufd, int flags, const struct __kernel_itimerspec *utmr, struct __kernel_itimerspec *otmr)

register	value
`r1`	320, the syscall number
`r2`	int ufd
`r3`	int flags
`r4`	const struct __kernel_itimerspec *utmr
`r5`	struct __kernel_itimerspec *otmr
`r2`	the return value

Then run svc 0 to enter the kernel.

Same syscall on other architectures