The Design And Implementation Of Operating System Support

With the rapid development of computer technology, the computer has been used in many fields and many kinds of operating systems are developed to satisfy different requirements. Because the operating systems are designed to meet different application needs, there are many differences in the design and implementation between the operating systems. For this reason the API provided by operating systems is different so that it is difficult to port application codes from one system to another and maintenance the application, even in some situations it need recode the program. The telecommunication products, whose main task is about sending, receiving or retransferring data when overtime, need the OS to be stable and highly efficient, especially in memory management and timer management.Being aimed to the application environment of telecommunication products and the operating systems differences, Operating System Support (OSS) subsystem is designed and implemented. It lies between OS, which is the lower layer and the application, which is in the upper layer. OSS is an adaptable layer to lower OS. Through the development based on lower OS and the simple encapsulation of API interface, OSS can shield the difference of the lower OS API, provide the universal API to upper layer application and enhance the code portability.Based on studying of the design principles of OS and the differences between the operating systems, this paper points out that it is necessary to research OSS and introduces its architecture. The design and implementation of the timer management and memory management are illustrated in detail; In addition, the design and implementation of the interrupt, message queues, network communication, task schedule, semaphore, exception protection, system monitor and application routines are introduced. At last, this paper gives the application of OSS in the BAS (Broad-band Access Server) product and points out what need to be improved.The OSS provides a universal platform for application. It has been widely used in telecommunication products, network products and so on. This paper is valuable for OSS researching.