res := make([]byte, len(b))
	copy(res, b)
	E2a(res)
	if trimRight {
		str = string(bytes.TrimRight(res, " \x00"))
	} else {
		str = string(res)
	}
	return
}

func fdToPath(dirfd int) (path string, err error) {
	var buffer [1024]byte
	// w_ctrl()
	ret := runtime.CallLeFuncByPtr(runtime.XplinkLibvec+SYS_W_IOCTL<<4,
		[]uintptr{uintptr(dirfd), 17, 1024, uintptr(unsafe.Pointer(&buffer[0]))})