提供了一个最基础的USB驱动程序，即USB骨架程序，可被看做一个最简单的USB设备驱动实例。 usb类驱动的信息,为了从usb核心得到一个次设备号,并取得注册的核心设备驱动- provides a the most fundamental of the USB driver, namely USB skeleton program can be regarded as one of the most simple USB device driver examples. Usb class driver info in order to get a minor number from the usb core,and to have the device registered with the driver core