timerfd_settime

timers that notify via file descriptors

sys_timerfd_settime32(int ufd, int flags, const struct old_itimerspec32 *utmr, struct old_itimerspec32 *otmr)

register	value
`r20`	307, the syscall number
`r26`	int ufd
`r25`	int flags
`r24`	const struct old_itimerspec32 *utmr
`r23`	struct old_itimerspec32 *otmr
`r28`	the return value

Then run ble 0x100(%sr2, %r0) to enter the kernel.

Same syscall on other architectures