链路层是指提供对物理层访问的设备驱动程序，这可以是各种介质，例如串口链路或以太网设备。
The link layer refers to the device drivers providing access to the physical layer, which could be numerous mediums, such as serial links or Ethernet devices.
串口访问测试的小程序，我也是看别的地方的，希望对大家有帮助！
Visit the small test procedures, I also look at other places, and I hope to be helpful!
对串口的访问。
应用推荐