A Flash File System to Support Fast Mounting for NAND Flash Memory Based Embedded Systems

摘要

In embedded systems, NAND flash memory is typically used as a storage medium because of its non-volatility, fast access time and solid-state shock resistance. However, it suffers from out-place-update, limited erase cycles and page based read/write operations. Flash file systems such as JFFS2 and YAFFS, allocate memory spaces using LFS (Log-structured File System) to solve these problems. Because of this, many pieces of a file are scattered through out flash memory. Therefore, these file systems should scan entire flash memory to construct the data structures during the mounting. This means that it takes a long time to mount such file systems on a large chip. In this paper, we design and propose a new flash memory file system which targets mobile devices that require fast mounting. We experimented on the file system performance and the results show that we improve the mounting time by 64%-76% as flash usage compared to YAFFS.