Building Embedded Network Realtime Streaming-Media Device Based On Linux System

With the development of computer, network, communications and multimedia technology, the embedded system has become a new focus and orientation in IT field following the step of computer and network technology. Open source Linux operating system has a lot of advantages, such as cheap, powerful, efficient and easy to porting. It has been an agreement in the industry that Linux is the trend in embedded system design. So, the research and development embedded Linux software and hardware system is useful.The research of building embedded Linux system is based on the development of network real-time media terminals, because embedded system design is application oriented and media terminals can be widely used in many fields, such as videoconference, e-learning and network monitoring.The embedded hardware board of the media terminal has a high flexibility and reusability, which is composed with several sub-boards (the core board with MCF5249 processor, the media sub-board which includes MPEG4 ASIC and the other interface sub-boards).A friendly development environment has been built of the embedded system, which integrates the serial interface, Ethernet interface, BDM interface and cross-platform development toolchain.An embedded software system includes: BootLoader, OS kernel, Root Filesystem and user applications. The software of media terminal has a kernel which is configured from uCLinux and a flexible BootLoader. And the file system of the embedded system integrates Romfs, Ramfs, JFFS2 and NFS basing on the basis of MTD driver and Blkmem driver for flash chip.The development environment of this embedded system has been proved well in the development process of the media terminal. And the media terminal which was built on the basis of our embedded system works well.