Storage Subsystem Implementation for Mobile Embedded Devices

摘要

Recent dramatic advance of NAND technologies leads increasing storage capacity for mobile devices. In mobile storage system, IO storage subsystem is composed of legacy file system and flash translation layer (FTL). In this paper, we address the design issues for IO subsystem for developing mobile devices in consideration with NAND flash memory component. Since FTL itself software layer, it can be reside within operating system or within NAND chip package. We insist that it is better that FTL is reside in host side not NAND side. Based on this decision, the IO subsystem is revisited. The designed storage subsystem includes simple and efficient FTL structure and journaling interface for fast journal. With the storage subsystem, IO characteristics can be applied into existing IO requests, resulting in better performance.