【作者】 杜春侠；

【导师】 栾新；

【作者基本信息】 中国海洋大学 ， 计算机应用技术， 2006， 硕士

【摘要】 随着后PC时代的来临,嵌入式系统在各个领域得到广泛应用。随着设备复杂度的提高,嵌入式软件系统也越来越复杂。嵌入式产品开发人员希望开发的嵌入式软件系统可以在多种平台上移植,针对不同的开发需要,只需对相应部分进行移植扩展,而不需要重新设计整个嵌入式软件系统。但目前各嵌入式操作系统的API没有形成统一的规范,各厂商都有自己的标准,且对于不同的硬件没有统一的规范和接口。操作系统技术规范差别之大、使用的微控制器之繁多、各种中间件扩展的不同、各种外设接口的不同,使得嵌入式软件系统的重用性、移植性及扩展性出现了一系列的问题。因此,如何提高嵌入式软件的移植性、重用性和扩展性,如何提高嵌入式软件的开发质量和开发效率成为亟待解决的问题。嵌入式软件设计开发的难点在于硬件与软件接口、硬件驱动与实时操作系统、硬件板级设置与实时操作系统、应用程序与底层软件之间没有统一的标准接口。将嵌入式软件系统的设计和开发建立在一个通用型、移植性、裁剪性、实时性强的层次化、标准化嵌入式开发平台上是一个很好的解决方案。本文分析了嵌入式系统及嵌入式软件开发的特点,提出了基于平台的嵌入式软件系统的层次结构和基于平台的设计方法,对每层的实现方法进行了定义和描述。该层次结构类似于网络通信中的OSI模型,将嵌入式软件系统划分为相对独立的层:硬件抽象层、引导程序BootLoader层、监控程序ROM Monitor层、硬件设备驱动层、实时操作系统层、中间件和应用程序层。每层完成相应的功能,并对上层提供支持,层层之间都有统一的接口规范。搭建一个标准的通用平台,当应用需求发生变化时,只需对相应层进行修改。在此平台上开发设计嵌入式系统,采用层次化、标准化的方法,可大大缩短系统的开发时间、降低成本、实现嵌入式技术的快速移植和扩展。根据该方法搭建了基于T-Kernel的嵌入式软件系统。T-Kernel是标准开源实时操作系统内核,具有移植性和实时性较好的标准化实时内核及标准化硬件、软件、开发更多还原

【Abstract】 With the coming of Post-Personal Computer Era, embedded system is widely used in more and more fields. The embedded software system is also becoming much more complicated and difficult. How to transplant the embedded software system from one platform to another only by extending corresponding layers, without redesigning the whole system, is the goal of all the embedded developers all the time. But there is no standard interface between different embedded system APIs. There are so many differences between OS APIs, OS specifications, middle-ware interfaces and hardware drivers. It is just the great differences that lead to a series of problems in embedded software systems’reuse, portability and expansibility. Therefore, how to improve the portability and the expansibility of the embedded software and the quality and the efficiency of developing becomes a key and difficult problem.In order to resolve this problem, to design and develop an embedded software system based on a hierarchical and standard platform with strong portability and real timing, is a good approach. After analyzing the characteristics of embedded system and software developing, this paper proposes the framework of embedded software system and the design process of embedded software based on platform, where the designing method of each layer is described in details. This framework is similar to OSI model of the network communication, dividing the embedded software system into several independent levels, including Hardware Abstract Layer, BootLoader Layer, Monitor Layer, Hardware Device Driver Layer, Real-Time Operating System Layer and Application Layer. Each layer accomplishes corresponding function and provides support to upper layers. There are uniform interfaces between different levels. Based on this, we only need to modify更多还原