[OLPC-devel] OLPC "bootloader"

[Thomas Gleixner]

On Mon, 2006-06-12 at 12:01 -0600, Jordan Crouse wrote:
> One thing I noticed is that we need a good way to write a new image to
> the NAND flash.  I'm sure this has probably been discussed in other
> e-mail threads or on IRC, but as far as I know, there really isn't a
> consensus on how we want to do this.
> 
> I think the initrd is as good a place to do it as any - we could pull
> a new .jffs2 image from a USB key or the network (or, heaven help us,
> zmodem) and write it to the MTD block.  The code isn't at all complicated,
> its just a matter of agreeing on how things will be done.
> 
> Anyway, I'm going to start pulling down things and playing around a bit - 
> let me know if you have anything I can help with.

It was discussed that we use UBI - a logical volume manager for FLASH -
which was developed by IBM to solve similar problems. Today the design
paper went online on the MTD website, the code will follow after some
cleanups have been done in course of the week.

The most important features:

- support for "atomic updates"
- resizable volumes vs. fixed partitions
- wear levelling across the whole FLASH device vs. wear levelling inside
partitions.

http://www.linux-mtd.infradead.org/doc/ubi.html

	tglx