U-boot and UBI

U-boot and UBI

[Nigel Hathaway]

Hoping to avoid re-inventing the wheel....

It would seem that there are a number of people who are independently
porting UBI to U-Boot. I notice that there is a thread on the subject on
this mailing list (linux-mtd) from April 2008. It has also been
indicated to me that IBM have, in fact, done a port of UBI to U-Boot,
but haven't released any source code (yet). Does anyone know if this is
true?

It would seem sensible to somehow coordinate the effort.

Re: U-boot and UBI

[Bernard Blackham]

Nigel Hathaway wrote:
> Hoping to avoid re-inventing the wheel....
> 
> It would seem that there are a number of people who are independently
> porting UBI to U-Boot.

I expressed interest in doing so at the time but nothing happened about 
it unfortunately. I can't speak for anyone else though.

Bernard.

RE: U-boot and UBI

[Nigel Hathaway]

Bernard,

> Nigel Hathaway wrote:
> > Hoping to avoid re-inventing the wheel....
> > 
> > It would seem that there are a number of people who are
independently
> > porting UBI to U-Boot.
>
> I expressed interest in doing so at the time but nothing happened
about 
> it unfortunately. I can't speak for anyone else though.
>
> Bernard.

In the short term we've found a way to get round having to UBI and hence
porting it to U-Boot (we have a NOR/NAND combination, and we've gone for
the NAND as entirely jffs2).

However, the next spin of our product will use entirely NAND flash: it
will use an SoC which has an internal ROMboot and can load U-Boot
directly from NAND flash. We will have to go to UBI then (starting
development early 2009).

I have been playing around with a board from Olimex: the SAM9-L9260 (it
has an Atmel AT91SAM9260 on it). This has a ROMboot with U-Boot in NAND
flash. The board I am using has an interesting feature: the block which
U-Boot is configured to use for storing its environment just happens to
be a bad block, so I can't change and store the U-Boot environment
parameters on it.

Either the U-Boot that comes pre-flashed into the board (v1.2.0) is
misconfigured, or that version of U-Boot has failed to take into account
the possibility of the scenario described. Either way, there would
appear to be some work to do to get U-boot up-to-date with Linux MTD
state-of-the-art.

Nigel

Re: [U-Boot-Users] U-boot and UBI

[Scott Wood]

On Thu, Jul 31, 2008 at 12:01:18PM +0100, Nigel Hathaway wrote:
> I have been playing around with a board from Olimex: the SAM9-L9260 (it
> has an Atmel AT91SAM9260 on it). This has a ROMboot with U-Boot in NAND
> flash. The board I am using has an interesting feature: the block which
> U-Boot is configured to use for storing its environment just happens to
> be a bad block, so I can't change and store the U-Boot environment
> parameters on it.

There's a patch in the testing branch of u-boot-nand-flash to allow a
range of blocks to be specified for the environment, with bad blocks
being skipped.  Another patch has been posted to allow the location of
the environment to be specified in the OOB area of the boot block (which
is guaranteed to be good).

-Scott

U-Boot and UBI

[Josh Boyer]

Hi All,

As has been stated before by various people, IBM has added some form of
UBI support to an older version of U-Boot.  While we would love to be
able to forward port this to the latest version of U-Boot, we have
simply not found the time and don't see that being the case in the near
future.

So as an alternative, I have cleaned up the code slightly and pushed out
a version that applies to U-Boot 1.1.6.  This way there is at least some
form of code release that people can use as a reference.  I am not
pushing this for inclusion into the current U-Boot, as we are well aware
of the need for further adaptation and cleanup.

A few caveats:

- This is a quick forward port from a patched 1.1.4 tree to 1.1.6.  It
compiles for the example board (PowerPC 440EP Bamboo), but that example
code may not actually work due to the differences in how flash was read
between the code bases.  When moving to a newer U-Boot, I highly
recommend using the generic MTD interfaces.

- There might be slight differences in the UBI format that this code
base supports and what is in the upstream Linux kernel.  Comparison of
the data structures in the current kernel would be advised if you are
forward porting.

- There is no write support for UBI in this port.

- The interfaces have two methods of getting scan information.  The
first is having a bit of code that runs before U-Boot do the scan and
pass it.  The second is to have a user/script use the "ubiscan" command
to have U-Boot manually perform the scan itself.  The latter method is
likely more flexible for new boards.

All of that being said, we hope this code is useful as a guide.  I will
certainly answer questions as I can.  If for some unknown reason I find
a massive amount of spare time, I might even try to forward port it, but
that seems unlikely these days.

I would like to thank Frank Haverkamp, Thomas Gleixner, Andreas Arnez,
and Artem Bityutskiy for their work on UBI and the majority of the
U-Boot code we have.

The git tree can be found here:

git fetch git://git.infradead.org/users/jwboyer/u-boot.git ubi

http://git.infradead.org/users/jwboyer/u-boot.git?a=shortlog;h=refs/heads/ubi

josh