ColdFire/68K Microcontrollers and Processors中的主题 Re: ColdFire: JFFS2 Flash File System

ColdFire: JFFS2 Flash File System

c_ris — Tue, 27 Mar 2007 15:31:00 GMT

Hello!

I would like to port JFFS2 to my coldfire platform without OS. Can someone who has already done this give me some hints?

Would it be better to use YAFFS?. I know very little about it, but I have heard it is simpler and faster, is that true?
Thanks in advance
Cris

--
Alban Edit: addes part number + clarified subject

Message Edited by Alban on 2007-03-27 12:52 PM

Re: Flash File System

mccPaul — Tue, 27 Mar 2007 16:39:11 GMT

Either one of these should be portable to the Coldfire architecture, but I suspect that yaffs would be easier, simply because it is less closely linked to Linux and more ports have been made already.

Have you considered the licensing implications? Both of these are GPL'd so your bare metal application will also have to be GPL because of the viral nature of GPL. There are other alternative licenses for yaffs, but you'd need to check with Aleph1 (http://www.aleph1.co.uk/node/33).

If you can't use GPL source or can't afford Aleph1's license fees, then you may want to consider writing a less ambitious filing system yourself. A full blown journalling filing system may be overkill for an application that doesn't require an OS.

Cheers,

Paul.

Re: ColdFire: JFFS2 Flash File System

mjbcswitzerland — Tue, 27 Mar 2007 21:58:25 GMT

Hi c.ris

I also ask what requirements the file system has?

The uTasker uses the uFileSystem for managing parameters and storing files for use by web server etc.
It is a simple solution which works well on the M5223X - there is a full desciption of it here : http://www.uTasker.com/docs/uTasker/uTaskerFileSystem.PDF.

It can not be compared with the file systems you have quoted but a simple approach can prove to be fully adequate for the majority of tasks that are perfomred on an embedded processor. It requires around 2,3k of code on the Coldfire and the complete uTasker package is free for non-commerical work, including the uTasker simulator which also fully simulates the file system in FLASH on the M5223X.

Regards

Re: ColdFire: JFFS2 Flash File System

c_ris — Tue, 27 Mar 2007 22:21:42 GMT

Thank you Paul and Mark!

I`ll take a look to uTasker`s uFileSystem, but I was thinking in something specific for flash memories, that`s why I had chosen JFFS and YAFFS. Is there any other File System for flash memories?

Thanks
Cris