Internals

YAFFS provides a debugging mechanism which can be controlled at runtime, or set at build time. This page descirbes the options available and how to use them, for when you need to do some troubleshooting.

YAFFS has been designed in a very modular way, with the file-system-specific code kept separate from the main YAFFS file system code. This allowes YAFFS to be ported quite cleanly to other operating systems through operating system personality modules. One such personality module is the YAFFS Direct Interface (YDI) which allows YAFFS to be simply integrated with embedded systems, with or without an RTOS.

This document describes how to use the YAFFS Direct Interface with your OS/Environment, as well as providing sufficient information to allow a preliminary evaluation of YAFFS.

YAFFS stands for "yet another flash file system"(*). As far as I am aware, YAFFS is the only file system, under any operating system, that has been designed specifically for use with NAND flash. YAFFS is thus designed to work within the constraints of, and exploit the features of, NAND flash to maximise performance. YAFFS uses journaling, error correction and verification techniques tuned to the way NAND typically fails, to enhance robustness. The result is a file system that exploits low-cost NAND chips and is both fast and robust. YAFFS is highly portable and runs under Linux, ucLinux and Windows CE. YAFFS is an open source project.