基于NAND FLASH的文件系统设计与实现

发布时间：2018-01-17 18:10

本文关键词：基于NAND FLASH的文件系统设计与实现　出处：《华东师范大学》2012年硕士论文　论文类型：学位论文

更多相关文章： 嵌入式 Nand Flash 文件系统

【摘要】：随着计算机以及嵌入式技术的发展,数字产品日益普及,非易失性NAND Flash已经成为各种嵌入式移动平台和数字产品的主要存储介质。NAND Flash具有功耗低、读写速度快、较大存储容量、制造成本低、抗震耐腐蚀等优点。随着不断增大的Nand Flash存储芯片容量,如何管理NAND Flash上的文件成为了研究的热点。目前主要的对应NAND Flash的文件系统有YAFFS、JFFS、UBIFS。由于较好的稳定性,当前使用最为广泛的是YAFFS文件系统。然而在实际使用中,YAFFS也存在两点不足：1)挂载速度会随着NAND Flash的容量,以及文件系统中文件数量的增加而增加；2)YAFFS文件系统在垃圾回收时没有考虑NAND Flash的磨损平衡问题,不能有效地延长Flash的使用寿命。针对以上两点,本论文提出了一种基于NAND Flash的文件系统NEOYAFFS文件系统。在挂载速度方面,本论文利用NAND Flash硬件实现原理,提出了一种基于NAND Flash实现的超级块功能。类似于只有在硬盘上才能实现的超级块功能,在其上存储整个文件系统的文件结构信息,以此来减少在挂载文件系统时读取的数据量,达到挂载速度优化的目的。在磨损平衡问题上,本论文在YAFFS文件系统的基础上,增加了磨损平衡算法,在每个NAND Flash块中存储了该块的擦除次数,当文件系统执行垃圾回收时读取该信息,优先选择擦除次数低的块擦除,以此达到磨损平衡。论文所做工作有效提高了文件系统的挂载速度,并提供了更好的磨损平衡。
[Abstract]:With the development of computer and embedded technology, digital products are becoming more and more popular. Non-volatile NAND Flash has become the main storage medium of various embedded mobile platforms and digital products. NAND Flash has the advantages of low power consumption, fast reading and writing speed and large storage capacity. With the increasing capacity of Nand Flash memory chip, how to manage the files on NAND Flash has become a hot topic. At present, the main file systems corresponding to NAND Flash are YAFFSU JFFSU UBIFS. due to good stability. Currently the most widely used is the YAFFS file system. However, in practical use, there are two deficiencies: 1) the mount speed will depend on the capacity of the NAND Flash. And the increase in the number of files in the file system; 2YAFFS file system does not consider the wear balance of NAND Flash in garbage collection, so it can not prolong the service life of Flash effectively. This paper presents a file system NEOYAFFS file system based on NAND Flash. In the aspect of mount speed, this paper uses NAND Flash hardware to realize the principle. This paper presents a super block function based on NAND Flash, which is similar to the super block function which can only be realized on the hard disk, on which the file structure information of the whole file system is stored. In order to reduce the amount of data read in the mount file system, to achieve the purpose of the optimization of mount speed. On the issue of wear balance, this paper increases the wear balance algorithm based on the YAFFS file system, and stores the erasure times in each NAND Flash block. This information is read when the file system performs garbage collection and the block erasure with low erasure times is preferred to achieve wear balance. The work in this paper improves the mount speed of the file system and provides a better balance of wear and tear.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP368.1

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