该文档的功能是创建一个简单的字符设备驱动，压缩包里包含module_hello和user_hello，其中module_hello文件夹里面包含了hello.c字符驱动代码和MakeFile文件，经过编译可生成相应的.ko模块；user_hello是用户程序，经过编译后可生成相应的可执行文件，执行用户的可执行文件可对相应的字符设备进行读写操作。-The document' s function is to create a simple character device driver, compression bag containing module_hello and user_hello, which module_hello folder which contains the character-driven code and MakeFile hello.c file, compiled to generate the corresponding. Ko module　user_hello is user program is compiled to generate the corresponding executable file, the executable file can be executed on the user' s corresponding character device for read and write operations.