Debugging Of Embedded System And The Development Of Devices Drives

With the rapid development of information technology and computer network, embedded system has being more and more widely used in science research, military, engineering design, computer, commnication, and consumer electronic, et c. Embedded system centres on application and bases on computer techonolgy, it's hardware and software can be cut off by users, and is suit for a special computer operating system that has limitation with function, reliability, cost, cubage and power waste. You will face with two aspects if you develop embedded system by Linux: first is rebuild operating system, including reducing kernel or rewriting derectly memory management of Linux and the mechanism of process call; the second is the design and develop of devices drivers.In this paper, I emphasize on the development of devices drivers. It can be divided into some parts as follow.First, it starts with system structure and kernel of embedded Linux system. I study particularly on the across-compile environment based on X-scale kernel PXA255 hardware platform and the interrupt mechanism of Linux. And then I investigate the transplantation technology of embedded Linux system, which includes replanting Bootloader and migrating embedded Linux kernel. I generalize the steps of migration in detail.Second, I analyze the design theory and method of devices drivers, introduce the conception of modularization, and make an anatomy about the method how to write, compile and debug devices drivers. Devices drivers are the collection of subprogram and data, they are the software interfaces of I/O devices and provide interface function to the system. So programming drivers means to realize these functions. Drivers can be divided into three types: character device drivers, block device drivers and network device drivers. I study the design of device drivers and program them.Through my research based on peripheral equipment drives program, I contrive the models of character device dirvers and block device drivers. The two models should finish nearly all transactions that have relationship with kernel, including the interface with function registers, logout, open, close, write and read, also including the method with which sends data from kernel to user and so on. The paper studies the use of memory and the access mode to equipment too. Based on above, if a developer wants to write his device driver, he only needs to be familiar with the hardware information, such as the working of peripheral equipment and the data type. Safe precautions are added to the module for reliability in my paper.