Research And Application On Network Device Driver In Linux

With the rapid development of computer technology and communication technology,the application of embedded system has affected all aspects of people’s life deeply;and network device has become an indispensable part of embedded system in the age of network as Internet gets popularization rapidly.Moreover,Linux operating system has become the most widely used operating system in embedded system because of its open source,tailoring ability and powerful network function.Thus,the study of network device driver in Linux operating system has a very important practical significance.Besides,File Transfer Protocol(FTP)data transmission is a widely used service in the information age and FTP system is needed in many embedded systems.However,there are few FTP systems with open source and most of the FTP systems on the market have the disadvantages of functional redundancy or low efficiency.The research and design of FTP system based on demand seems particularly important thus.This subject is based on the laboratory project of maskless exposure machine.In order to supply stable and efficient transmission service for exposuring data,the embedded Linux system platform is constructed and specific network device driver is realized.Stable network transmission servieces are supplied to the upper application thus.Then,an embedded FTP server software is designed and implemented according to specific project requirements.And the specific work is as follows:(1)Embedded system platform is constructed based on TQ2440 development board.Firstly,cross-compile environment is built and the system development tools are installed and configured on the host.Then,uboot on the platform is transplanted and related work including the compilation of Linux kernel and the production of root file system is being done then according to the hardware platform.Finallly,a complete embedded Linux platform is built,which lays the foundation for driver development and server development.(2)The architecture of network device driver is studied deeply.Specially,two key data structures of sk_buff and net_device are analyzed specifically.In order to realize the function of network device driver,based on specific DM9000 card,related development work of network device driver is carried out,including the initialization function of network device,the open and release function of network device,the sending and receiving function of data packet and the interrupt handing function.At last,the network card driver is compiled into the Linux kernel and the driver function and performance are tested.(3)According to specific needs of the project of maskless exposure machine,related functions of embedded FTP server system are designed.Firstly,the advantages and disadvantages of various server models are analyzed and the design scheme of multi process model is proposed.Then,the overall framework of FTP server system is implemented and various functions of FTP server are realized.Finally,makefile files are writen and downloaded to the target board after they are compiled successfully,and the functions of the server will be tested with the help of the standard FTP client software.