The Research Of Real-Time Technique On Linux-Based Embedded Operating System

With the rapid development of integration of Computer technology and Communication technology in Information times and the broad application of Internet, it is inevitable that the trend of 3C (Computer, Communication and Consumer) has come into being which will change the core of Computer Industry from Calculating product to Information product with the new concept of Information Appliance. In the domain of application and exploitation of Information Appliance, Embedded Operating System will be the most favorite pet in Software Development field. At the same time, in the domain of computer science itself, the micromation and specialization is the new direction in computer development. It also requires the support of Embedded System. Therefore, it is very important and effective to research the key technique of embedded system-Embedded Operating System.Establishing Embedded Operating System with linux is the most inspiring project in recent years with various reasons. First, Linux on embedded systems can provide all functions of desktop computing, and is very convenient to be customized because of its opening source code. Secondly, Linux also supports most of the new microprocessors used in embedded designs, including StrongARM, MIPS and PowerPC. Finally, Linux is free, without any charge for it's use. Therefore using linux as basic operating system has become a popular solution in Embedded Operating System.The demand for real-time operating system (RTOS) by omnipresent embedded computing is becoming more and more urgent. The real-time supporting research of Linux kernel has offered the new possibility tomeet this demand. In this paper, we have discussed the actuality of the real-time OS and the deficiency of the standard Linux in real-time applications. And we also analyzed the reasons which caused these deficiencies from the implementation mechanism. Furthermore, we have studied and implemented the real-time support of Linux kernel and made Linux a perfect RTOS through four aspects: interrupt control, real-time scheduling policy, kernel preemption and high resolution timer .As a hardcore of the embedded Linux system research project, we have reserved the original system function and API of Linux, and made the real-time part a configurable unit. We have worked over real-time scheduling policies as many as possible and feasible projects which can extent the system's applicable range. At the same time, we have also pointed out the shortage of the present scheme and the study direction we should follow in the future.