From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Date: Thu, 03 Jan 2008 07:05:15 +0100 Subject: [U-Boot-Users] [PATCH] ARM: DAVINCI: Write ECC understandable by RBL In-Reply-To: References: <477BF231.30704@googlemail.com> Message-ID: <477C7B1B.1060307@googlemail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de ksi at koi8.net wrote: > On Wed, 2 Jan 2008, Dirk Behme wrote: > > I think it is not right. Let us try to be a little more precise, not so general and don't mix things ;) As you didn't comment below technically on any line of the patch, it seems to be technically correct. So please apply. > 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. If I got it right you already introduced two different U-Boot versions with your Davinci patch. One to be used for NOR and one for NAND? Or can a U-Boot configured via davinci_dvevm.h for NAND used in NOR? > What version are you going to use as a main one? The one compatible with kernel of course. See below as well. > Remember, if you have saved U-Boot environment in NAND only one version > will > be able to read it... I don't have to remember this because I'm aware of it ;) Did you notice that I mentioned 2nd stage NAND loader? Because of its 14k size limitation, this will never be U-boot. So I never talked about writing this special U-Boot version to NAND. Sorry if I was unclear regarding this. > First of all, I don't think it is the U-Boot task to write RBL. We never write RBL cause its in ROM? Did you mean NAND first stage UBL (2nd stage NAND loader)? > I think > it's > up to the initial bootloader to do this. Okay, that's your opinion. I and maybe others may want to have a U-Boot to write 2nd stage NAND loader because of U-Boot powerful options (tftp, command line, dump & diff etc.). Therefore I made it as an option for everybody wanting to use this and knowing what he/she does. It doesn't touch anything else. If you don't like, ignore it and use your bootloader. But let others finding this usful use it. > 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. Why do you think it was unnoticed? Do you remember that it was me answering to it? So at least one noticed it ;) > It was able to write both itself _AND_ U-Boot in NAND while > booting up a virgin DaVinci board through serial port. Yes, I know. See above: Maybe others prefer other ways to do this. > 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. Yes, this is the first good technical point :) I did it this way, first, cause it is only for some experts as explained above. I made it as small and non-intrusive as possible. Second, is there an *easy* way to extend the NAND related command set without being too intrusive to non-Davinci code? I think changing a lot of non-Davinci code only for this special feature wouldn't be a real option. But you are right, technically it would be the cleanest way. Thanks for your comments, Dirk >> 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 >> > > --- > ****************************************************************** > * KSI at home KOI8 Net < > The impossible we do immediately. * > * Las Vegas NV, USA < > Miracles require 24-hour notice. * > ****************************************************************** >