Re: Developer board for NetBSD flash file system development

Ferenc Havasi <[email protected]> Thu, 17 Jun 2010 15:47:50 +0200
Newsgroups gmane.os.netbsd.devel.embedded,gmane.os.netbsd.ports.arm
Message-ID <[email protected]>
Hi Jesse,

> I probably have a few other boards you could try.  I can get you any 
> board from our product line for free-- I'd really like to see a flash 
> filesystem developed for NetBSD.  In fact, I have a prototype board 
> with a dual core 650Mhz ARM11 I just bootstrapped NetBSD support for 
> but haven't yet commited to CVS.

It is very big help for us, if you can provide us ARM developer 
board(s). The exact type of it/these is almost the same for us, the 
bigger its NAND flash size the happiest we will - and certainly good 
NetBSD support.

> Be aware of some of the details of the different NAND chips, there are 
> 512b sector chips, 2k sector chips, and 4k sector chips.  Each also 
> have different erase block sizes and different requirements for ECC 
> (MLC vs SLC, reed-solomon vs. hamming codes).  My strategy lately is 
> to just create a simple high reliability block layer and run regular 
> old filesystems on top of it-- I'd like to hear more about your plans.
At this moment we are (almost) ready with:
- a flash layer: it is similar to MTD
- a wear-leveling layer: it is similar to UBI

We are strongly working on a JFFS2 like flash file system. Almost all 
directory functions work, now working on file read/write. At this moment 
it is based on UFS, but considering to ignore it in the future.

Cheers,
Ferenc