The Technology Of Linux-based Embedded System & Its Application

Embedded system will result in the pervasive computing in modem society. It isn抰 a new thing in concept but is really going fashionable and irresistible only with the rapid development of information technologies motivated by the advanced computing ,communication and the in-depth application of the Internet The research and development for embedded system is consequently having been attractive and significant It抯 essentially a reasonable and also brave attempt for Linux initially designed for PC platform to be used as embedded operating system. This thesis throughly analyzes the characteristic of the Embedded Linux, discussing and figuring out the tasks and the hard nuts pertinent in a Router project based upon Embedded Linux & mpc86O. Concretely, this paper mainly concerns the following issues: I. Pointing out the advantage and disadvantage of Linux used as embedded operating system, and setting forth the common tasks faced in building such an embedded Linux system. 2. How to custome the standard Linux (for PC) to be fit for the application defined by a specific embedded system. The double-kerneled idea adopted by RT-Linux is detailed and the means based on LKM is put forward to communicate between the kernel and user applications. 3. Introducing the principle and debugging means of BSP code, pointing out the problems and the countermeasure while debugging the BSP, overcoming the related issues in starting up the router and building the x86-hosted cross development environment for ppc target. 4. Based on the insight of Linux network internals, the viewpoint and the way of rebuilding the model of the current protocol stacks is put forward to satisfy,?the requirement for the router to forward packets via connection-based network interfaces. The scheme resolving the dynamic routing function performed by a Linux-based router is also brought out.