The Research On Embedded Linux System And Device Driver Based On ARM9

With continuous improving performance and declining prices of processors, because of small size, high reliability, strong function, flexibility, and many other advantages, the embedded systems has been widely used into industry, agriculture, education, national defense, scientific research , daily life and other fields. The Linux system has so many adventages such as the open source, versatile, stable performance, so it becomes the first choice of the embedded systems. The wide types and different performances of embedded devices add to the complexity of the design on the drive. Therefore, the development of device driver holds an important position in the embedded system design.This article describes the development and architecture of Linux, and represents advantages and disadvantages of Linux as an embedded system. In practice, combining S3C2440 processor and Mini2440 experimental platform, the embedded Linux is ported and device drivers are developed. In the process of embedded Linux porting, firstly build cross development environment based on embedded Linux system and experimental platform, and solve the problem of compatible versions among softwares. Secondly, generate the appropriate system boot procedures by revising open-source Uboot to complete the pre-order steps of Linux system porting, which mainly solve data porting problems in the process of NandFlash starting. Finally, after Linux kernel cutting and transplantation, design USB devices, LCD devices and network devices before successful porting.This paper is structured into four parts:(1) The developing status and structures of embedded Linux system in USB devices.(2) Introduce hardware features of the USB circuit, LCD circuit, etc.(3) Develop embedded Linux. This includes the process of cross-compile compiling environment, Uboot structure and porting process, Linux kernel analysis and related cutting port, the production of yaffs root file system.(4) Describe driver architecture and implementation process of the common device, including USB devices, LCD devices and network devices.After the above work, this article not only offers a complete process for embedded Linux system design and device driver development, but also provides a reference for other developers.