嵌入式系统的软件研究与开发
摘要
同步技术是嵌入式系统与传统PC应用软件实现交互以及未来移动终端共享网络资源的关键技术。本文讨论如何设计和实现一个采用驳接方式连接的掌上平台和桌面系统间的同步软件。
同步系统是掌上电脑功能外延的必备软件，旨在将用户最近所做的PIM记录或文件的更新在数据同步结束后一致的出现在两个平台上。本文提出了一个与操作系统平台无关、与具体应用程序无关、底层数据传输与设备无关的设计模型，并且基于组件化的设计思想，将同步系统划分为同步管理器和同步组件。
本文阐述了同步数据对象的定义以及对其更新的监听策略；为了向下兼容各种传输端口，改进SLIP协议，增添了数据校验；同时采用基于流水号的应答机制，保证了出错、丢失数据包的重发。依照UML动态模型中状态视图的规范描绘同步系统的状态迁移并提出了基于有限状态机的解决方案。
依照设计模型实现基于嵌入式Linux的掌上电脑和以Outlook为PIM软件的桌面系统间的同步软件。Windows端的同步组件遵循COM规范，使用自动化对象技术完成与Outlook的交互；Linux端则使用动态加载的共享组件来实现。另外对线程同步、组件注册、屏幕闪烁等实现问题提出了解决途径。
Synchronization technology is widely used for the interaction between the embedded system and the traditional personal computers. And it will soon contribute to share the network resource used by mobile devices. This paper discusses how to design and implement one synchronization software among the palmtop device and the desktop platform. These two platforms link to each other directly.
Synchronization system is indispensable for the plamtop device to enhance its function, which supports data synchronization between the two platforms. This paper introduces a device-independent design model having nothing to do with the platform of operating system and individual applications. On the basis of the design philosophy of the components, synchronization system can be divided into Sync Manger and Sync Components.
This paper defines the Sync objects and explains how to monitor and detect their changes. As to support various kinds of transmission ports, we add data check-up to improve SLIP agreement. At the same time the request-reply mechanism based on serial number is designed to retransmit the data which has mistakes or be lost. Following the standard of status view provided by UML, we describle the status changes during the process of Sync and put forward the solution based on limited states machine.
We implement Sync software among the palmtop computer based on embedded Linux and desktop system taking Outlook as PIM software according to the model of design. The Sync component of Windows end follows COM standard , and use automation technology to act on Outlook; Linux end uses dynamic sharing package to realize the components. Furthermore, such problem as thread synchronism, component registration, screen flickering, are provided suitable solutions.
同步系统是掌上电脑功能外延的必备软件，旨在将用户最近所做的PIM记录或文件的更新在数据同步结束后一致的出现在两个平台上。本文提出了一个与操作系统平台无关、与具体应用程序无关、底层数据传输与设备无关的设计模型，并且基于组件化的设计思想，将同步系统划分为同步管理器和同步组件。
本文阐述了同步数据对象的定义以及对其更新的监听策略；为了向下兼容各种传输端口，改进SLIP协议，增添了数据校验；同时采用基于流水号的应答机制，保证了出错、丢失数据包的重发。依照UML动态模型中状态视图的规范描绘同步系统的状态迁移并提出了基于有限状态机的解决方案。
依照设计模型实现基于嵌入式Linux的掌上电脑和以Outlook为PIM软件的桌面系统间的同步软件。Windows端的同步组件遵循COM规范，使用自动化对象技术完成与Outlook的交互；Linux端则使用动态加载的共享组件来实现。另外对线程同步、组件注册、屏幕闪烁等实现问题提出了解决途径。
Synchronization technology is widely used for the interaction between the embedded system and the traditional personal computers. And it will soon contribute to share the network resource used by mobile devices. This paper discusses how to design and implement one synchronization software among the palmtop device and the desktop platform. These two platforms link to each other directly.
Synchronization system is indispensable for the plamtop device to enhance its function, which supports data synchronization between the two platforms. This paper introduces a device-independent design model having nothing to do with the platform of operating system and individual applications. On the basis of the design philosophy of the components, synchronization system can be divided into Sync Manger and Sync Components.
This paper defines the Sync objects and explains how to monitor and detect their changes. As to support various kinds of transmission ports, we add data check-up to improve SLIP agreement. At the same time the request-reply mechanism based on serial number is designed to retransmit the data which has mistakes or be lost. Following the standard of status view provided by UML, we describle the status changes during the process of Sync and put forward the solution based on limited states machine.
We implement Sync software among the palmtop computer based on embedded Linux and desktop system taking Outlook as PIM software according to the model of design. The Sync component of Windows end follows COM standard , and use automation technology to act on Outlook; Linux end uses dynamic sharing package to realize the components. Furthermore, such problem as thread synchronism, component registration, screen flickering, are provided suitable solutions.
引文
[1] Microsoft Corporation Microsoft Developer Network 2001.4
[2] IBM Corporation www.ibm.com/developerWorks/cn/
[3] Trolltech Corporation www.trolltech.com/developer/
[4] 潘爱民 《COM原理与应用》清华大学出版社 1999
[5] Rick Grehan等著，许汝峰译《32位嵌入式系统编程》中国电力出版社2001
[6] Michael Barr著，于光宏译《C／C++嵌入式系统编程》中国电力出版社2001
[7] Charles Petzold著 北京博彦科技公司译 《Windows程序设计》1999
[8] David J．Kruglinski著 潘爱民，王国印译 Microsoft Press《Visual C++技术内幕》 1999
[9] 蒋立源 《编译原理》 西北工业大学出版社，1993
[10] Jams Rumbaugh，Ivar Jacobson，Grady Booch著 姚淑珍，唐发根等译《UML参考手册》机械工业出版社 2001
[11] Microsoft Corporation著 北京超品计算机公司《Outlook2000编程》编程 2000
[12] K．Wall，M．Waton，M．Whitis著 王勇，王一川，林花军，甘泉译作《GNU／Linux编程指南》清华大学出版社 2000
[13] 郑泽胜撰写 嵌入式系统以及实时软件开发 www.pocketix.com
[14] 嵌入式系统以及如何构造一个嵌入式系统概览 bbs.tsinghua.edu.cn
[15] 北京科泰公司．ZYCO操作系统简介．2001．10
[16] 程序员杂志技术专题Qt——飞翔的心 2002．2
[2] IBM Corporation www.ibm.com/developerWorks/cn/
[3] Trolltech Corporation www.trolltech.com/developer/
[4] 潘爱民 《COM原理与应用》清华大学出版社 1999
[5] Rick Grehan等著，许汝峰译《32位嵌入式系统编程》中国电力出版社2001
[6] Michael Barr著，于光宏译《C／C++嵌入式系统编程》中国电力出版社2001
[7] Charles Petzold著 北京博彦科技公司译 《Windows程序设计》1999
[8] David J．Kruglinski著 潘爱民，王国印译 Microsoft Press《Visual C++技术内幕》 1999
[9] 蒋立源 《编译原理》 西北工业大学出版社，1993
[10] Jams Rumbaugh，Ivar Jacobson，Grady Booch著 姚淑珍，唐发根等译《UML参考手册》机械工业出版社 2001
[11] Microsoft Corporation著 北京超品计算机公司《Outlook2000编程》编程 2000
[12] K．Wall，M．Waton，M．Whitis著 王勇，王一川，林花军，甘泉译作《GNU／Linux编程指南》清华大学出版社 2000
[13] 郑泽胜撰写 嵌入式系统以及实时软件开发 www.pocketix.com
[14] 嵌入式系统以及如何构造一个嵌入式系统概览 bbs.tsinghua.edu.cn
[15] 北京科泰公司．ZYCO操作系统简介．2001．10
[16] 程序员杂志技术专题Qt——飞翔的心 2002．2