Research And Design On CPS Node Operating System Oriented Module Loading Method

CPS (Cyber Physical System), with extensive application prospects, is a new generation of system that is constructed base on the embedded computing, wireless sensor networks, it has been developed rapidly with computing technology, control technology. CPS system has been a major research point of many countries and universities, among which, CPS node systems is an important direction of research. In the process of working of sensor nodes, sometimes it is necessary to replace or update the applications of operating systems, therefore, research and design module loading method that meet the demand of operating systems, is the foundation of constructing a node operating system.In this thesis, based on the referring to a large amount of literatures, the wireless sensor networks are analyzed in detail, and based on the requirement of the CPS node operating systems, the research target of node operating system module loading method is proposed:real-time, reliability, scalability, flexibility. In order to improve the flexibility and scalability, etc, this thesis designs loadable modules and dynamic linking method, according to the characteristics of the node operating system, compiling the application into a loadable module, and the loadable module is dynamic linked during loading, so that it can be flexibly and effectively to load modules.In this thesis, firstly, analysis the typical module loading method deeply, on this basis, research the loadable module, module loading technology, and the communication method between modules deeply. Secondly, based on the analysis of standard ELF file format, design the compact ELF-CELF file format, in the CELF, compress the ELF data structure is compressed, symbol tables and relocated tables, etc, are simplified, and some useless sections are deleted; modules need to be loaded are compiled into CELF file format. Thirdly, dynamic linking and communication between the modules are detail designed, dynamic linking ensures the flexibility of operating system; after module loading, through the communication between module and kernel, communication between modules, ensure the coordination between the various modules, and then guarantee the normal work and the reliability of operating system. Finally, through theoretical analysis and simulation experiments, verify the module loading method that designed in this thesis, it turns out proving that the module loading method designed in this thesis basically meet the design goals and the needs of CPS node operating system, it has the value of further research and can be used in real applications.