Analysis And Design Of Network Device Driver For Home Network Based On Embedded Linux

With the development of network technique, network comes into the common life ofmost people and it forms a roboticized Home Network System, which has abundantcontents. Ethernet technique is more suitable than other for the native actuality, becauseof the mature technique twopenny cost, better compatibility, extendable bandwidth anddense suitability, so it is a perfect internal network technique.As a network interface card (NIC) under home network environment, not only it canprovide information communication for traditional IP packets, optimize the datathroughput and ensure the data transfer. But also for the faster development multimediaapplications, it can provide integrative service including voice, graph, image, video,cartoon and such on. These distributing multimedia applications require morebandwidth, lower delay and lower dithering. As the driver of NIC, it should givedifferent treatment for those special applications.Based on above requirement, a famous international electric company of Japan providesa bran-new stratagem of "Home Network Terminal". The stratagem regards theembedded home network terminal as core, and the faster Ethernet as the backbone ofhome local bus, which also combine multi-network. So the Japanese parent companyand its semiconductor company, which lies in American Silicon, cooperate with ISCAS(Institute of Software China Academy of Science) for starting this development. TheETH100 is a very important part for this stratagem.This task has been finished in March of 2004, and the development result has beenaccepted by three sides: Japanese parent company, American semiconductor and ISCAS.After the first product coming into mass-production in the Japanese market inSeptember of 2003, as the replacer of NIC component of the first, the SoC combinedETH100 has been produced. The second generation with it will have better performancefor multimedia environment.In this cooperation project, the author takes on the works of design, development andhardware validation. Also author concerns with various auto-test routine for testinghardware.This thesis primary describes three aspects during the NIC development:1) Implement an integrated network device driver. This thesis studies the device driver of hone network and implements the basic functions. It focuses on the faster DMA transfer mode and discovers two bugs of hardware development platform in actual design. Then it uses the software solution in device driver.2) Deduce a probability formula of hardware filter under multicast model. ETH100 adopt the international popular development platform with FPGA hardware validation. So the most important work, from the level of software and application, is to validate the hardware design by software modeling and routine simulating. Furthermore, provides the improvement advice to the Semiconductor Company.Based on the implementation of supporting multicast model, this text analyses the process of hardware filtering. And discuss the mapping relation between hardware registers and memory hash table addresses, then deduce probability formula of hardware filter under multicast model. This formula is applied in the development item, and provides theoretical supporting for improving the hardware design. With it, we have succeeded in validating the hardware design.3) Implement the QoS strategy control in driver. QoS strategy control provides the transfer assurance for multimedia data with the character of high bandwidth, low delay, low dithering. This text introduces the relational content of QoS, and emphasizes the analysis of RED strategy. As an example, RED strategy is implemented on driver layer.