【作者】 余婷婷；

【导师】 刘岚；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2007， 硕士

【摘要】 随着嵌入式计算机技术的发展，外部存储设备成本逐渐下降，与之相对的嵌入式应用所请求的数据量却日益剧增。如何有效的管理设备及其数据，成为嵌入式系统开发中的重要问题。作为嵌入式实时操作系统的组件，嵌入式文件系统提供专业化的数据存取和外部设备管理功能。嵌入式系统的特点决定了嵌入式文件系统与普通桌面文件系统具有较为明显的差异。嵌入式系统物理内存的局限决定了嵌入式文件系统必须具备代码紧凑、按需配置的特点，在应用不使用文件系统的极端情况下，文件系统不能对系统造成任何的代码负担和开销；其次，嵌入式文件系统应该尽可能独立于硬件体系结构，因此在实现上应该具有较好的移植性；再次，文件系统是嵌入式系统的一个组成模块，作为系统的一个可加载选项提供给用户，由用户决定是否需要加载。本课题基于化学发光测试系统的研究，因此针对化学发光测试系统对文件系统的要求，设计出基于FAT格式的文件系统，其体系结构分为三个层次，自底向上分别为：块设备驱动层、文件系统核心层、应用程序接口层。满足了化学发光测试系统对于文件系统的性能要求：结构紧凑、代码量小，支持多种存储设备，可移植等。此外，由于本文件系统提供了灵活的应用层API接口和设备驱动管理接口，便于化学发光测试系统的未来升级和扩展。本文首先研究了常见的嵌入式外存设备和文件系统技术，然后提出了基于FAT格式嵌入式文件系统的体系结构，详细讨论了各子模块的设计方案和具体实现，并设计了嵌入式文件系统对常用外部设备的驱动。文章最后对课题的成果和不足做出了总结，并对嵌入式文件系统的发展趋势进行了展望。更多还原

【Abstract】 With the development of embeded computer technology, cost of outside storage devices is decreased gradually, comparatively the data count which embeded application required is increased day by day. How to administer those devices and data effectively becomes an important problem of embeded system development. As a component of embeded realtime control system, the embeded file system offers the specific function of data storage and outside devices administration.Characters of embeded system caused relatively obvious differance between embeded file system and usual desk file system. Firstly, the limitation of embeded system’s physical storage decides that embeded file system must has its code tight, and couldn’t cause any code cost to system when no file system is being used. Secondly, embeded file system should be separated with hardware system structure as possible as it could, thus it should contain good ability of replanting when being realized. Thirdly, file system is a component of embeded system, which is offered to users as a selection and decided by users whether to load or not.The project based on Chemical Irradiance Detecting System, so take requirement of Chemical Irradiance Detecting System into considerration, we design a file system based on FAT format, architecture of the file system contains three parts form bottom to top : manage layer for drivers, file system kernel layer and application interface layer. This architecture satisfied the demands of Chemical Irradiance Detecting System, such as compact code, support sevrel storrige devise and good ability of replanting. Besides, this file system offers smart application layer API interface and devices drivers administration interface, in order to make Chemical Irradiance Detecting System update and expandsion in future easy.This paper does researchs about usual embeded outside devices and technology of file system, then offers a system structure of embeded file system based on FAT format, describes design plans and concrete realization of each submodules in detail, and designs drivers of usual outside devices which used by embeded file system. At last, this paper makes some conclusions about achievements and shortages of this project, and gives a preview of the development trend of embeded file system.更多还原