【作者】 于鹏飞；

【导师】 王德广；

【作者基本信息】 大连交通大学 ， 计算机应用技术， 2008， 硕士

【摘要】 嵌入式产品正以不可思议的速度闯入人们的日常生活。MP3、MP4、智能家电、智能手机等电子产品到处可见。嵌入式系统也逐渐成为当前最热门的研究方向之一。这些现象表明,嵌入式时代已经在不知不觉中来临。随着硬件技术的飞速发展,设备存储容量也越来越大,这满足了人们对嵌入式产品数据存储方面的需求,但同时也给嵌入式系统数据管理带来了诸多问题。若继续沿用传统的数据管理模式,不但会影响系统的性能,而且也无法对嵌入式存储设备进行合理的管理。因此,为嵌入式系统设计一套文件管理系统,对大量的复杂的数据资源进行有效的管理是十分必要的。论文针对嵌入式流行存储设备Flash的特点,设计并实现了以Flash为存储设备和μC/OS-II系统为运行平台的嵌入式文件系统。系统采用日志文件系统设计思想,使Flash存储设备得到更加合理的利用。文件系统采用模块化分层设计的原则,分为四层结构,在传统的闪存转换层基础上进行了大规模的设计,让其能够兼容多种设备;将文件系统和设备驱动程序分离开来,使得文件系统具有了支持多种设备的性能。该系统为应用程序开发提供统一的、标准的API函数,具有良好的可维护性和移植性。文件系统树组织形式上选择了以文件索引节点号为关键字的B+树形式。针对日志型文件系统加载速度慢的特点,设计了文件摘要区的结构,用来保存该块上的文件索引信息,从而大大加速了文件系统的初始化速度。本文件系统已经在HHARM9-EDU开发平台上进行了实际测试,运行实践证明该系统是成功的,系统运行是可靠的。在此基础上还对文件系统写操作中出现的异常终止进行了检证。更多还原

【Abstract】 Embedded products have penetrated into the daily lives of people with an incredible speed. Electronic products, such as MP3, MP4, intelligent household appliances, and smart phones, are seen everywhere. Embedded system has become one of the most popular research direction gradually. All of these show that an era of embedded products comes unwittingly. The rapid development of hardware technology boosts the capacity of embedded products, which meets the needs of people for higher-capacity embedded products. But this also brings some problems in data management. If the use of the traditional pattern of data management is to be continued, the system performance will be adversely affected. In addition, the traditional pattern is no longer an optimal solution for managing storage equipments. Therefore, a new file system should be designed for embedded systems to manage the large number of complex data resources.In this thesis, a new embedded file system running onμC/OS-II is designed based on the characteristics of flash memory storage device on embedded systems. It is a log-structured file system with reasonable use of Flash Memory. This file system using modular design principles, the structure is divided into four levels, a large scale design is carried on it based on the traditional Flash Translation Layer which can allow compatible with a variety of equipment. Separate the file system from the equipment driver, making it can support multiple devices with performance. This system provides the unification, the standard API function for the application procedure development, therefore it has good maintainability and portability. The file system has selected B+ tree as it’s organizational form which using index nodes as it’s keyword. Summary document area used for the preservation of indexing information has designed in view of the slowly loading speed, therefore the speed of file system initialization is greatly accelerated.The file system has been tested on HHARM9-EDU development platform, which proved that it is successful and reliable. An examination has also carried on for the abnormal termination during writing.更多还原