[RFC] Add .dts file for Netgear ReadyNAS 102
ezequiel.garcia at free-electrons.com
Tue Jul 2 19:23:12 EDT 2013
I feel I might share some of my findings when I worked on this,
in the hope it's useful for anyone.
On Wed, Jul 03, 2013 at 12:09:36AM +0200, Willy Tarreau wrote:
> > Which matches what Thomas wrote in a previous email regarding pwa3xx
> > base.
> Yes and indeed I must say that when I read the driver I found some
> similarities with pxa3xx, though it was done differently. I initially
> wanted to try to merge them but of course without the spec it's a huge
> waste of time, especially considering that this is still in the roadmap
> of the Free Electrons guys even though low priority.
I wish I could say I'm going to work on this soon but, as Thomas said,
we have no idea when/if NAND will be prioritized.
On the other side if you look at the driver Willy just posted, merging
the juicy stuff into pxa3xx-nand driver is not for the faint of heart.
Without the spec, is only tougher.
Just a quick hint. As far as I can recall, one of the first items in a
TODO list should be:
* adding bigger page support to pxa3xx (4 KiB, 8 KiB).
Willy's posted driver might be helpful to accomplish this;
provided your eyes don't melt when you look at it :-)
* once the above is done, bad block management can/should be added.
With these two we're almost there for R/W support.
> Since I'm now flashing a rootfs from within u-boot, support for the
> NAND is of less importance to me than what it used to, but I have no
> problem with helping with my very limited time. I have 3 machines
> with this controller (mirabox, openblocks AX3, and an XP-GP, though
With my latest patches pxa3xx-nand should at least *detect* the NAND
device in XP-GP. Doesn't work for Mirabox, though.
> the AX3 only has NOR IIRC). I can do some tests if you manage to get
> the driver to work again.
> Be very careful when playing with this, the driver expects the partition
> table to be passed from u-boot as "armada_nand", and if it uses the wrong
> partition layout, you can be certain that ubifs will destroy them at the
> first mount attempt. That's how I initially bricked my mirabox and did so
> repeatedly. Better keep a copy before booting the patched kernel!
> Another point, I had to add a new entry for the Micro 8Gb flash of the
> mirabox, maybe you won't need it or maybe you'll need a different one.
Just a note about this. You need that entry because your driver doesn't
support ONFI-detected flash devices. You could workaround that, by
adding support simple command. I did it for pxa3xx-nand recently:
"mtd: nand: pxa3xx: Add address support for READID command"
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
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