LINUX_SYS_linux_clock_gettime
: "a"(LINUX_SYS_linux_clock_gettime), "D"(clock_id), "S"(ts)
register long svc asm("x8") = LINUX_SYS_linux_clock_gettime;
: "a"(LINUX_SYS_linux_clock_gettime), "b"(clock_id), "c"(ts)
case LINUX_SYS_linux_clock_gettime: