With the development of information technology and popularization of digital production, embedded systems cored with computer technology, chip technology and software technology become the hotspot of current research and application again. The trend of the combination of communications, computers and electronic technology in consumption is coming into being. Networks everywhere and computing everywhere is bringing human being into a brand-new information society. With the improvement of hardware's real-time requirement, the software scope of embedded systems becomes larger and larger and RTOS is gradually to be the mainstream of embedded systems. After our deep and meticulous analyse of uCLinux Operation System and RTAI, we made a great deal of design and enhancement according to the requirement of real-time and applications and finally we worked out a hard real-time Operating System-ZDRTOS. This paper illustrates the design and implementation of memory management mechanism in ZDRTOS.This paper consists of four chapters. The first one describes embedded systems briefly, which contains the history and actuality of embedded systems, architecture of embedded systems and then brings out some critical points in the development and research of embedded systems. The second chapter introduces the current popular Linux embedded system. Firstly introduces the advantages of selecting Linux embedded system, then lists some keys needs to be understood before developing embedded Linux, and at last we describe the characteristics of uClinux, the main frame of ZDRTOS. The contents in chapter 3 deal with the design scheme of the memory management system in ZDRTOS, which consist of systematic introduction, the position of the memory management system in embedded systems, the store mediums in embedded systems, processors' support to memory management, the functional design of memory management module, the use of Cache and the use of TLB. The last chapter illustrates real implementation of the memory management mechanism of ZDRTOS. We analyse the current memory management mechanism of uCLinux and RTAI and re-design and enhance them according to the requirements. It then refers to the support of shared libraries in ZDRTOS and finally summarizes the ZDRTOS' performance. |