[U-Boot-Users] [PATCH] ARM: DAVINCI: Write ECC understandable by RBL

[ksi at koi8.net]

On Wed, 2 Jan 2008, Dirk Behme wrote:

I think it is not right.

By making this a configuration choice (read compile-time) you introduce two
different U-Boot versions; one being able to write RBL _BUT_ incompatible
with the kernel ECC, another one being compatible with kernel _BUT_ not
being able to write RBL. What version are you going to use as a main one?
Remember, if you have saved U-Boot environment in NAND only one version will
be able to read it...

First of all, I don't think it is the U-Boot task to write RBL. I think it's
up to the initial bootloader to do this. You don't have U-Boot on a fresh
virgin board anyways so you use some kind of initial bootloader to boot that
board. So why not use that same bootloader for writing itself in NAND? I did
post the full source of such a bootloader to Davinci list where it went
unnoticed. It was able to write both itself _AND_ U-Boot in NAND while
booting up a virgin DaVinci board through serial port.

If this feature is to be integrated in U-Boot, it should be done as an
extension to NAND-related command set so one would be able to choose which
ECC to use for writing to NAND at the _RUN_ time.

> ARM based TI DaVinci devices have a RomBootLoader (RBL) which is able
> to load a 2nd stage user defined loader from NAND into internal RAM
> and start it there. This RBL expects a special ECC format (4 byte big
> endian) as calculated by DaVinci hardware. Make U-Boot able to write
> this RBL compatible format if user selects it in configuration.
>
> Signed-off-by: Dirk Behme <dirk.behme at gmail.com>
>

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