This paper describes the design and implementation of SD card driver and tiny file system for multi-process micro-kernel embedded operating system on ARM in technical details, including structure of device driver, key techniques of designing SD card driver, architecture of the tiny file system, a brief description of its designing and a demo example. The SD card driver and tiny FS are implemented with GNU tool chain by the author of this paper. Practice proves that the system can be used for not only embedded application developments but also related curriculum teaching.