The Design And Implementation Of MiniOSEK Operating System Based On Servent And Exe_flow Model

With the continuous progress of automobile technology, the electronic components used in automotive controling are becoming more and more, which making the automotive electronic control systems more and more complex, and the automotive applications software development has become increasingly difficult. At the early 90s of the 20th century, to reduce the difficulty of the development of automotive applications software, the European automotive industry community launched the OSEK/VDX standard. The standard screening the distinction between the different electronic controling components, and providing a unified interface for the application developers, which reduced development costs and shorten development time.At home and abroad, there are many researchs about the OSEK /VDX standard, also some OSEK operating systems meet thestandards. But the existing OSEK operating system is designed on the existing process/thread model which have some problems. Such as asynchronous communication between threads lead the real-time of a system is not high; the thread/process abstraction increased the operating costs, reduce the efficiency of the system; and the thread/process model is not conducive to the compiling of highly efficient procedures.To solve the problems existing in the OSEK operating systems, such as low real-time performance and efficiency, this thesis proposes a new OSEK operating system, namely, MiniOSEK, which is built on the servent and exe-flow model, and in accordance with the OSEK/VDX standard.The main contributions of this paper are as follows:Firstly, the article firstly analyzes the significant meanings of the OSEK/VDX standard produced, especially the importance of the operating system specification. Then it pointed out the shortcomings of the existing OSEK operating system in real-time and efficiency, and puts forward a practical purpose of builting the MiniOSEK operating system.Second, Framework design. According to research of OSEK OS standard and the analysis of servent and exe_flow model,the article proposes the design ideas of the MiniOSEK and the operation of the operating system process.Third, Realization. Based on the OSEK standard towards the requirements of each module, the paper achieves the various modules one by one, including the data structure of each module and the corresponding API functions. During the implementation process of the API functions, it introduces the idea of the message-driven, that when a user program needs to access to the core services bodies which provided the API function , it only needs to send a message to the appropriate API function .Forth, Performance Analysis. IN the end, the paper explaines how to use MiniOSEK operating system, and does the operating system functional testing. From the test results, MiniOSEK is in line with the OSEK standard, and MiniOSEK uses message-driven mode to switching context, which shorts the time of the context switching, and improves the system's real-time.