The existing JFFS2 flash file system recompresses a file already compressed in user level such as multimedia files when writing the file, so reiteration of data compression can befall for a number of files. When reading a file, moreover, unconditional...
The existing JFFS2 flash file system recompresses a file already compressed in user level such as multimedia files when writing the file, so reiteration of data compression can befall for a number of files. When reading a file, moreover, unconditional usage of disk caches causes unnecessary memory access. Because of two vulnerable points, the file system is not suitable for supporting low power system. Thus, this work presents a modified JFFS2 file system applied by both the selective data compression technique to avoid repetitive data compression at writing a file and the selective page caching technique for preventing unnecessary RAM access at reading a file. This modified file system used in Linux running on a PDA shows effectiveness of reduced energy consumption.