utimensat_time64

change file timestamps with nanosecond precision

sys_utimensat(int dfd, const char *filename, struct __kernel_timespec *utimes, int flags)

register	value
`r6`	412, the syscall number
`r0`	int dfd
`r1`	const char *filename
`r2`	struct __kernel_timespec *utimes
`r3`	int flags
`r0`	the return value

Then run trap0(#1) to enter the kernel.

Same syscall on other architectures