Robust Flash Storage Since 2002    

YAFFS - Proprietary

YAFFS, for Yet Another Flash File System, is a file system optimised for the popular NAND Flash chips. It is a log-structured (Journalled) FS which automatically provides wear-levelling and robustness on power failure. It also scales well for large Flash chip sizes, in terms of boot time and modest RAM usage. It is in use now in several commercial products under Linux, WindowsCE, and various RTOSs, and has proved extrememly reliable.

Its heart, YAFFS/direct, can easily be incorporated in RTOSs and embedded systems. Bootloader code and documentation are available. It will work with NOR Flash and RAM too, though efficient use of the particular properties of NAND Flash chips remains the primary design goal.

YAFFS is a whole product bundle which contains YAFFS/direct and other components of code used to integrate YAFFS/direct into a real product environment. The final integration code for a particular environment may already exist, or may be written by us or by you, the user, or other collaborators, depending on the target OS and hardware.

Full documentation and developer information is available. 

YAFFS/direct code is available either under GPL or under our own licence, which allows its use with proprietary software.


Check out YAFFS for yourself. Access to the latest code is via CVS. This code is governed by the GPL.

If you wish to purchase a proprietary licence to YAFFS, then the price is negotiable and would usually include help specific to your device. Please contact us to discuss your requirements.

Circumstances where you need to licence YAFFS other than under the GPL include:-

  • If you want to run a statically-linked commercial RTOS on top of a YAFFS filesystem
  • if you want to sublicence yaffs to your customers (under terms other than the GPL)
  • If you want to use YAFFS with WindowsCE version 4.  (WinCE version 3 can use GPL code but WinCE v.4 needs an additional filesystem interface layer which is not part of YAFFS. This would cost a few thousand GB£ to implement.)

While YAFFS is released under GPL we can provide standard support options, consulting in its application to your particular product, or development of specific features to suit your needs or hardware. Paid Licences are available in certain circumstances, for example Licences to redistribute YAFFS to your customers. The price is a matter of negotiation.