Design And Implementation Of File System On Embedded Storage Devices

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.