[Yaffs-archive] YAFFS update

[Charles Manning]

Hi yaffsers

Been offline for a while....

I expect to shortly be CVSing the following:
* Some bug fixes to the YAFFS guts.
* Support for pipes and devices (now YAFFS can be used as a root fs).
* Utility to make a yaffs loadable image from a host directory.

In the last few weeks I have been head down, bum up doing an exploratory  
WinCE port of YAFFS. The results will be GPLed. The WinCE port wraps up the 
yaffs guts in a WindowsCE FSD (File system Device) allowing usage as a normal 
file system by WinCE applicaitons. The device even boots off an image held on 
the YAFFS fs.

The benefits of this are that more people are now using YAFFS and it is being 
tested on more flavours of hardware etc by more people. It also helps 
partition problems into VFS (ie. Linux interfacing) vs YAFFS guts.

We have tested this on real hardware (StongARM-based) with NAND arrays in 
various sizes from 32MB up to 256MB so far and bigger sizes to follow. This 
has flushed out a few minor (but important) bugs. Robustness has been 
excellent and I have not had any corruptions in three weeks of 
development-style abuse.

Performance is excellent when compared to a commercial (FAT-based) 
NAND solutions out there - by a factor of 1.5 to about 200 depending on the 
operation mix. As a sampler:
* Flat-out write speed (1MB writes). 1.2MB/s.
* YAFFS-to-YAFFS copy using the WinCE file explorer. The data is read off 
YAFFS  and written to a new file on YAFFS in 64kB chunks. 500kB/s.
* Copy 11MB file from host over USB ActiveSync. Approx 26 seconds - most of 
which is USB transfer time.
* Delete an 11MB file. 5 seconds.

-- Charles




---------------------------------------------------------------------------------------
This mailing list is hosted by Toby Churchill open software (www.toby-churchill.org).
If mailing list membership is no longer wanted you can remove yourself from the list by 
sending an email to yaffs-request@toby-churchill.org with the text "unsubscribe" 
(without the quotes) as the subject.