嵌入式动态可配置实时操作系统HDC-ReOS的研制——进程管理
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摘要
在以计算机技术、通讯技术相结合的信息时代的快速发展和互联网的广泛应用的形势下，3C(Computer、Communication、Consumer)合一的趋势已经形成，其结果必然是将计算机工业的重心从计算机产品转移到信息产品，从而出现信息家电的概念。信息家电是将数字技术和网络技术集成在电冰箱、洗衣机等传统家用电器上，藉此建立起家庭网络化环境。在信息家电的应用开发领域，随着其功能不断拓展和需求的不断增长，嵌入式系统开发将成为重点。同时在计算机自身的领域里面，微型化和专业化成为了发展的新趋势，同样也需要嵌入式系统的支持。嵌入式系统被描述为以应用为中心，软硬件可裁减的、适应应用系统对功能、可靠性、成本、体积、功耗等综合性严格要求的专用计算机系统。嵌入式系统主要由嵌入式处理器、相关支撑硬件、嵌入式操作系统及应用软件系统等组成，它是集软硬件于一体的可独立工作的“器件”。 嵌入式操作系统(Embedded operating system)是一种实时的、支持嵌入式系统应用的操作系统软件，它是嵌入式系统(包括硬、软件系统)极为重要的组成部分，通常包括与硬件相关的底层驱动软件、系统内核、设备驱动接口、通信协议、图形界面、标准化浏览器(Browser)等。
因此，研究嵌入式系统中最关键的技术——嵌入式操作系统有着相当重要的实际意义。
针对上述问题，本课题组在前期研制完成的、具有自主知识产权的嵌入式操作系统的基础上，研究开发嵌入式动态可配置实时操作系统。主要内容包括进程管理、内存管理和设备管理等几个方面。本论文的主要研究内容是嵌入式动态可配置实时操作系统中的核心部分——进程管理。
本文首先分析了被广泛应用的嵌入式操作系统μ Clinux的内核结构，指出了其在实时性方面所存在的缺陷；其次，对本系统的研制思路作了集中介绍，本系统采用双内核结构，在改进后的μ Clinux的基础上添加一个实时内核，并采用最早期限优先(EDF)进程调度算法，进一步加强其实时性。并且根据本操作系统应用于信息家电这一特点，对操作系统的时间片分配机制进行改进，大大提高了系统的响应时间。最后，通过实验证明HDC-ReOS(HDC-Reconfigurable Embedded Operating System)操作系统在实时性方面的优越性。
第一，阐述了课题的研究背景及其重要的研究意义；从嵌入式操作系统的理论研究和应用方面，对当前国内和国外嵌入式操作系统的研究动态进行分析。
摘要
第二，对嵌入式操作系统—“Clinux内核进行全面的剖析，深入分析了其各
个模块的具体实现及其小型化的具体方案。在此基础上，提出了对“Climix进行优
化的建议方案。
第三，针对p Clinux内核不适宜处理硬实时操作的问题，参考Rl:Linux的实
时性机制，提出了实时内核HDC一ReoS设计方案。作为该方案的核心工作，通过对
多种进程调度算法的分析比较，确定了最早期限优先算法为本操作系统的进程调度
算法并提出了面向信息家电应用的时间片分配机制，在此基础上给出了算法的详细
描述。
第四，叙述了HDC一RcoS设计方案的具体实现，并在基于Intel CPU的PC机
上编译运行HDC一RcoS操作系统;在基于ARM CPU的53C4510开发板上移植调试。
通过运行中断响应测试等程序，对完成的系统进行了验证。
最后，对本文的工作进行了总结并且对研究前景进行了展望。
With the development of Computer technology and Communication technology in Information times and the board application of Internet, it is clear that 3C (Computer, Communication and Consumer) will converge in the near future which will lead the focus of Computer Industry from the Compute product to Information product. It is the concept of Information Appliance. In the application and development field of Information Appliance, Embedded Operating System will be the most favorite thing in Software Development field. At the same time, in the field of computer science itself, the micromation and specialization is the new direction of the computer world. It also want the support of Embedded System. Embedded system is application-oriented special computer system which is scalable on both software and hardware. It can satisfy the strict requirement of functionality, reliability, cost, volume, and power consumption of the particular application. A typical Embedded system consists of a single-board microprocessor ,
peripheral hardware , Embedded Operating System and software development tools. It is a firmware which can run task. Embedded Operating System support Embedded System. They are also frequently real-time operating systems. It is the most important part of Embedded system. Frequently, it include operating system kernel, device driver, communication protocol, GUI, browser and so on.
So, the research of the key technique of embedded system--Embedded Operating
System is the most important thing.
This thesis firstly analyzes the kernel of Clinux which is used widely, and points to the defects in running real-time applications. Secondly, We design double kernel, add a real-time kernel to Clinux kernel, adopt to Earliest Deadline First Scheduling Algorithm, because of application-oriented Information Appliance, We redesign Clock Granularity for improving frequency of timer interrupts. At last, The experimental results show that the improvement gives a better result for applications with real time constraint than original Clinux kernel.
Firstly, we described the background of research and pointed out its significance. The domestic and foreign situation of Embedded Operating System research was analyzed from theoretical and applying aspects.
Secondly, we roundly analyze the kernel of Clinux, analyzing main function of
every module, and introduce Real-Time Kernel Design, Minimization and Optimization.
Thirdly, we point out the reason why μ Clinux can not suit for applications with real time constraint. And according to RT-Linux, we design our own real-time kernel-HDC-ReoS(HDC-Reconfigurable Embedded Operating System). Farther, according to comparing to manifold scheduling Algorithms, we select Earliest Deadline First Scheduling Algorithm as scheduling algorithm of our operating system.
Fourthly, our operating system have been compiled and run on Intel CPU, we are trying to porting our kernel to a new ARM platform.
Finally, all the results are summarized, and the study prospect is discussed.
因此，研究嵌入式系统中最关键的技术——嵌入式操作系统有着相当重要的实际意义。
针对上述问题，本课题组在前期研制完成的、具有自主知识产权的嵌入式操作系统的基础上，研究开发嵌入式动态可配置实时操作系统。主要内容包括进程管理、内存管理和设备管理等几个方面。本论文的主要研究内容是嵌入式动态可配置实时操作系统中的核心部分——进程管理。
本文首先分析了被广泛应用的嵌入式操作系统μ Clinux的内核结构，指出了其在实时性方面所存在的缺陷；其次，对本系统的研制思路作了集中介绍，本系统采用双内核结构，在改进后的μ Clinux的基础上添加一个实时内核，并采用最早期限优先(EDF)进程调度算法，进一步加强其实时性。并且根据本操作系统应用于信息家电这一特点，对操作系统的时间片分配机制进行改进，大大提高了系统的响应时间。最后，通过实验证明HDC-ReOS(HDC-Reconfigurable Embedded Operating System)操作系统在实时性方面的优越性。
第一，阐述了课题的研究背景及其重要的研究意义；从嵌入式操作系统的理论研究和应用方面，对当前国内和国外嵌入式操作系统的研究动态进行分析。
摘要
第二，对嵌入式操作系统—“Clinux内核进行全面的剖析，深入分析了其各
个模块的具体实现及其小型化的具体方案。在此基础上，提出了对“Climix进行优
化的建议方案。
第三，针对p Clinux内核不适宜处理硬实时操作的问题，参考Rl:Linux的实
时性机制，提出了实时内核HDC一ReoS设计方案。作为该方案的核心工作，通过对
多种进程调度算法的分析比较，确定了最早期限优先算法为本操作系统的进程调度
算法并提出了面向信息家电应用的时间片分配机制，在此基础上给出了算法的详细
描述。
第四，叙述了HDC一RcoS设计方案的具体实现，并在基于Intel CPU的PC机
上编译运行HDC一RcoS操作系统;在基于ARM CPU的53C4510开发板上移植调试。
通过运行中断响应测试等程序，对完成的系统进行了验证。
最后，对本文的工作进行了总结并且对研究前景进行了展望。
With the development of Computer technology and Communication technology in Information times and the board application of Internet, it is clear that 3C (Computer, Communication and Consumer) will converge in the near future which will lead the focus of Computer Industry from the Compute product to Information product. It is the concept of Information Appliance. In the application and development field of Information Appliance, Embedded Operating System will be the most favorite thing in Software Development field. At the same time, in the field of computer science itself, the micromation and specialization is the new direction of the computer world. It also want the support of Embedded System. Embedded system is application-oriented special computer system which is scalable on both software and hardware. It can satisfy the strict requirement of functionality, reliability, cost, volume, and power consumption of the particular application. A typical Embedded system consists of a single-board microprocessor ,
peripheral hardware , Embedded Operating System and software development tools. It is a firmware which can run task. Embedded Operating System support Embedded System. They are also frequently real-time operating systems. It is the most important part of Embedded system. Frequently, it include operating system kernel, device driver, communication protocol, GUI, browser and so on.
So, the research of the key technique of embedded system--Embedded Operating
System is the most important thing.
This thesis firstly analyzes the kernel of Clinux which is used widely, and points to the defects in running real-time applications. Secondly, We design double kernel, add a real-time kernel to Clinux kernel, adopt to Earliest Deadline First Scheduling Algorithm, because of application-oriented Information Appliance, We redesign Clock Granularity for improving frequency of timer interrupts. At last, The experimental results show that the improvement gives a better result for applications with real time constraint than original Clinux kernel.
Firstly, we described the background of research and pointed out its significance. The domestic and foreign situation of Embedded Operating System research was analyzed from theoretical and applying aspects.
Secondly, we roundly analyze the kernel of Clinux, analyzing main function of
every module, and introduce Real-Time Kernel Design, Minimization and Optimization.
Thirdly, we point out the reason why μ Clinux can not suit for applications with real time constraint. And according to RT-Linux, we design our own real-time kernel-HDC-ReoS(HDC-Reconfigurable Embedded Operating System). Farther, according to comparing to manifold scheduling Algorithms, we select Earliest Deadline First Scheduling Algorithm as scheduling algorithm of our operating system.
Fourthly, our operating system have been compiled and run on Intel CPU, we are trying to porting our kernel to a new ARM platform.
Finally, all the results are summarized, and the study prospect is discussed.
引文
[1] Gary Robertson, "A Survey of Embedded Operating System Abstract Introduction"
[2] Nicholas Mc Guire MiniRTL Hard Real-Time Linux for Embedded Systems, 1998
[3] Joe DeVita, "Development and Deployment of a Field Information Appliance"
[4] VxWorks Programmer'Guide 5.1 Wind River Systems 1993
[5] Dan Hildebrand, An Architectural Overview of QNX. The Proceedings of the Usenix Workshop on Micro-Kernels & Other Kernel Architectures, Seattle, April, 1992
[6] Victor Yodaiken and Michael Barabanov RT-Linux Version TWO Designdocumentation about RT-Linux in FSMLabs 1997.
[7] A System of Patterns-Pattern-Oriented Software Architecture by Frank Buschmann, Regine Meunier, Hans Rohnert, Peter Sommerlad and Michael Stal, 1996, 37-40
[8] Wang YC, Lin KJ. Implementing a general real-time framework in the RED-Linux real-time kernel. IEEE Real-Time System Symposium, 1999. 246～255.
[9] I. Ripoll and A. Crespo and A. Mok, 1996, Improvement in feasibility testing for real-time tasks, Journal of Real-Time Systems, pp19-40.
[10] μ Clinux White Paper Overview, Arcturus Networks Inc.
[11] Jinggang Wang Virginia Tech CS5204 Operating System Project: Real-Time Linux Kernel Design, Minimization and Optimization
[12] Getting Started with RT-Linux, FSM Labs, Inc. April 20, 2001
[13] Matt Sherer, Writing Applications with RT-Linux Finite State Machine Labs (FSM)
[14] T. P. Baker, 1991, Stack-Based Scheduling of Realtime Processes, Journal of Real-Time Systems, pp 67-99.
[15] S. Baruah and A. Mok and L. Rosier, 1990, Preemptively scheduling hard real-time sporadic tasks on one processor, IEEE Real-Time Systems Symposium, pp 182-190.
[16] Patricia Balbastre & Ismael Ripoll: Integrated Dynamic Priority Scheduler for RT-Linux
[17] C.L. Liu and J.W.Layland., 1973, Scheduling algorithms for multiprogramming in a hard realtime environment, Journal of the ACM, pp46-61.
[18] B. Nichols and D. Buttlar and J.P. Farrell, 1996, PThreads programming, O'Reilly, 1-56592-115-1.
[19] R. Rajkumar and L. Sha and J.P. Lehoczky, 1989, An Experimental Investigation of Synchronisation Protocols, Proceedings 6th IEEEWorkshop on Real-Time Operating Systems and Software, pp11-17.
[20] Dissecting DIAPM RTHAL-RTAI (with some comparisons to NMT-RTL, here and there) (draft). Paolo Mantegazza Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano. http://www.aero.polimi.it/～rtai/documentation/articles/ paolo-dissecting.html.
[21] L. Sha and R. Rajkumar and J.P. Lehoczky, 1990, Priority Inheritance Protocols: An Approachto Real-Time Synchronisation, IEEE Trans. On Computers.
[22] J. A. Stankovic and M. Spuri and K. Ramamritham and G. Buttazzo, 1998, Deadline Scheduling for Real-Time Systems: EDF and Related Algorithms, Kluwer Academic Publishers, 0-7923-8269-2.
[23] Luca Abeni and Giorgio Buttazzo. Integrating multimedia applications in hard real-time sys-tems. In IEEE Real-Time Systems Symposium, 1998.
[24] Mario Aldea and Michael Gonz alez Harbour. Posix-compatible application-de_ned schedulingin marte os. In Proceedings of 14th Euromicro Conference on Real-Time Systems, pages 67-75, 2002.
[25] P. Balbastre, I. Ripoll, and A. Crespo. Control task delay reduction under static and dynamic scheduling policies. In 7th International Confer-ence on Real-Time Computer Systems and Ap-plications RTCSA'00, 2000.
[26] Patricia Balbastre and Ismael Ripoll. Integrated dynamic priority scheduler for RT-Linux. In Third real-time linux workshop, 2001.
[27] I. Leslie, D. McAuley, R. Black, T. Roscoe, P. Barham, D. Evers, R. Fairbairns, and E. Hy-den. The design and implementation of an operating system to support distributed multimedia applications. IEEE Journal on Selected Areas In Communications, September 1996.
[28] C.L. Liu and J.W.Layland. Scheduling algorithms for multiprogramming in a hard real-time environment. JACM, 23:46-68, 1973.
[29] J. Stankovic, C. Lu, S. H. Son, and G. Tao. The case for feedback control real-time scheduling. In 11th Euromicro Conference on Real-Time Sys-tems, 1999.
[30] George Thanos and Yannis Mitsos. Porting CLinux-2.4 to MMU-less Microprocessors.
[31] Oikawa S, Rajkumar R. Portable RK: A portable resource kernel for guaranteed and enforced timing behavior. In: Proceedings of the IEEE Real-Time Technology and
Applications Symposium. Vancouver, 1999. 111～120.
[32] Daniel P. Bovet and Marco Cesati. Understanding the Linux Kernel. O'Really, 2003.
[33] Andrew Josey, editor. The Authorized Guide to Version 3 of the Single UNIX Speci_cation. Source Books from The Open Group. The Open Group, March 2002.
[34] Karim Yaghmour. The real-time application interface. In Linux Symposium, Ottawa Canada, July 2001.
[35] Victor Yodaiken and Micahel Barabanov. Fsmlabs RT-Linux psdd: Hard real-time with memory protection. 2002.
[36] L. Sha & al, 1990, "Generalized Rate-Monotonic Scheduling Theory: A framework for Developing Real-Time systems", Proceedings of the IEEE, Vol. 82, No. 1, pp 68-82.
[37] K. Yaghmour, 2001, "The Real-Time Application Interface", Proceedings of the Linux Symposium.
[38] Douglass Bruce Powel, 2000, Real Time UML Second Edition, Addison Wesley, ISBN0201657848.
[39] 毛德操，胡希明．Linux内核源代码情景分析．杭州：浙江大学出版社，2001．
[40] 李善平，郑扣根．Linux操作系统及实验教程．北京：机械工业出版社，1999．
[41] http://www.μClinux.org
[42] http://www.uClibc.org
[43] http://www.RT-Linux.org.
[2] Nicholas Mc Guire MiniRTL Hard Real-Time Linux for Embedded Systems, 1998
[3] Joe DeVita, "Development and Deployment of a Field Information Appliance"
[4] VxWorks Programmer'Guide 5.1 Wind River Systems 1993
[5] Dan Hildebrand, An Architectural Overview of QNX. The Proceedings of the Usenix Workshop on Micro-Kernels & Other Kernel Architectures, Seattle, April, 1992
[6] Victor Yodaiken and Michael Barabanov RT-Linux Version TWO Designdocumentation about RT-Linux in FSMLabs 1997.
[7] A System of Patterns-Pattern-Oriented Software Architecture by Frank Buschmann, Regine Meunier, Hans Rohnert, Peter Sommerlad and Michael Stal, 1996, 37-40
[8] Wang YC, Lin KJ. Implementing a general real-time framework in the RED-Linux real-time kernel. IEEE Real-Time System Symposium, 1999. 246～255.
[9] I. Ripoll and A. Crespo and A. Mok, 1996, Improvement in feasibility testing for real-time tasks, Journal of Real-Time Systems, pp19-40.
[10] μ Clinux White Paper Overview, Arcturus Networks Inc.
[11] Jinggang Wang Virginia Tech CS5204 Operating System Project: Real-Time Linux Kernel Design, Minimization and Optimization
[12] Getting Started with RT-Linux, FSM Labs, Inc. April 20, 2001
[13] Matt Sherer, Writing Applications with RT-Linux Finite State Machine Labs (FSM)
[14] T. P. Baker, 1991, Stack-Based Scheduling of Realtime Processes, Journal of Real-Time Systems, pp 67-99.
[15] S. Baruah and A. Mok and L. Rosier, 1990, Preemptively scheduling hard real-time sporadic tasks on one processor, IEEE Real-Time Systems Symposium, pp 182-190.
[16] Patricia Balbastre & Ismael Ripoll: Integrated Dynamic Priority Scheduler for RT-Linux
[17] C.L. Liu and J.W.Layland., 1973, Scheduling algorithms for multiprogramming in a hard realtime environment, Journal of the ACM, pp46-61.
[18] B. Nichols and D. Buttlar and J.P. Farrell, 1996, PThreads programming, O'Reilly, 1-56592-115-1.
[19] R. Rajkumar and L. Sha and J.P. Lehoczky, 1989, An Experimental Investigation of Synchronisation Protocols, Proceedings 6th IEEEWorkshop on Real-Time Operating Systems and Software, pp11-17.
[20] Dissecting DIAPM RTHAL-RTAI (with some comparisons to NMT-RTL, here and there) (draft). Paolo Mantegazza Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano. http://www.aero.polimi.it/～rtai/documentation/articles/ paolo-dissecting.html.
[21] L. Sha and R. Rajkumar and J.P. Lehoczky, 1990, Priority Inheritance Protocols: An Approachto Real-Time Synchronisation, IEEE Trans. On Computers.
[22] J. A. Stankovic and M. Spuri and K. Ramamritham and G. Buttazzo, 1998, Deadline Scheduling for Real-Time Systems: EDF and Related Algorithms, Kluwer Academic Publishers, 0-7923-8269-2.
[23] Luca Abeni and Giorgio Buttazzo. Integrating multimedia applications in hard real-time sys-tems. In IEEE Real-Time Systems Symposium, 1998.
[24] Mario Aldea and Michael Gonz alez Harbour. Posix-compatible application-de_ned schedulingin marte os. In Proceedings of 14th Euromicro Conference on Real-Time Systems, pages 67-75, 2002.
[25] P. Balbastre, I. Ripoll, and A. Crespo. Control task delay reduction under static and dynamic scheduling policies. In 7th International Confer-ence on Real-Time Computer Systems and Ap-plications RTCSA'00, 2000.
[26] Patricia Balbastre and Ismael Ripoll. Integrated dynamic priority scheduler for RT-Linux. In Third real-time linux workshop, 2001.
[27] I. Leslie, D. McAuley, R. Black, T. Roscoe, P. Barham, D. Evers, R. Fairbairns, and E. Hy-den. The design and implementation of an operating system to support distributed multimedia applications. IEEE Journal on Selected Areas In Communications, September 1996.
[28] C.L. Liu and J.W.Layland. Scheduling algorithms for multiprogramming in a hard real-time environment. JACM, 23:46-68, 1973.
[29] J. Stankovic, C. Lu, S. H. Son, and G. Tao. The case for feedback control real-time scheduling. In 11th Euromicro Conference on Real-Time Sys-tems, 1999.
[30] George Thanos and Yannis Mitsos. Porting CLinux-2.4 to MMU-less Microprocessors.
[31] Oikawa S, Rajkumar R. Portable RK: A portable resource kernel for guaranteed and enforced timing behavior. In: Proceedings of the IEEE Real-Time Technology and
Applications Symposium. Vancouver, 1999. 111～120.
[32] Daniel P. Bovet and Marco Cesati. Understanding the Linux Kernel. O'Really, 2003.
[33] Andrew Josey, editor. The Authorized Guide to Version 3 of the Single UNIX Speci_cation. Source Books from The Open Group. The Open Group, March 2002.
[34] Karim Yaghmour. The real-time application interface. In Linux Symposium, Ottawa Canada, July 2001.
[35] Victor Yodaiken and Micahel Barabanov. Fsmlabs RT-Linux psdd: Hard real-time with memory protection. 2002.
[36] L. Sha & al, 1990, "Generalized Rate-Monotonic Scheduling Theory: A framework for Developing Real-Time systems", Proceedings of the IEEE, Vol. 82, No. 1, pp 68-82.
[37] K. Yaghmour, 2001, "The Real-Time Application Interface", Proceedings of the Linux Symposium.
[38] Douglass Bruce Powel, 2000, Real Time UML Second Edition, Addison Wesley, ISBN0201657848.
[39] 毛德操，胡希明．Linux内核源代码情景分析．杭州：浙江大学出版社，2001．
[40] 李善平，郑扣根．Linux操作系统及实验教程．北京：机械工业出版社，1999．
[41] http://www.μClinux.org
[42] http://www.uClibc.org
[43] http://www.RT-Linux.org.