Research And Implementation Of Imbedded Real-time System Based On Linux

With the rapid development of computer technology, communication technology and consumer electronic technology, real-time system has been widely used. There are a lot of demands for real-time embedded operating system in fields of scientific research, engineering design, military technology, commerce entertainment etc. The purpose of my work is to design and realize a real-time embedded operating system.After introducing some relevant concepts, Linux operating system is analyzed and researched in this thesis, and makes it satisfy the requirement of realtime system and embedded system. Including minimizing kernel, minimizing file system and system booting, there parts are designed and realized on the aspect of embedded operating system. Connecting with system booting, this thesis introduces network booting and NFS file system. Connecting with kernel cutting, using modularized programming and loadable kernel module mechanism of Linux, some rules are give that decide what module will be compiled in the kernel. Connecting with file system cutting, ELF object file, dynamic and static link, standard C library and BusyBox concept have been used. On the aspect of real-time operating system, Linux has real-time task mechanism, but has not reached the hard realtime request. Key factors which influence real-time capacity are pointed out in the thesis by analyzing Linux schedule time and policy. There are a lot of improvement schemes to Linux real-time performance at present. Through analysis and comparison, RT-Linux is chosen to carry on the theoretical research and analysis, and make the test of real-time performance and obtain a better test results. Finally in my thesis, an embedded Firewall application based on the real-time embedded Linux has been complemented.