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Re: [beagleboard] How to compile u-Boot for BB XM rev B?


Jason Kridner May 5, 2011 9:27 AM
Posted in group: BeagleBoard
On Thursday, May 5, 2011 9:35:45 AM UTC-4, RobertCNelson wrote:
On Thu, May 5, 2011 at 3:20 AM, Pahtet <pahte...@gmail.com> wrote:
> Hello
> When i try to compile U-Boot using
> make CROSS_COMPILE=arm-none-linux-gnueabi- omap3_beagle_config
> make CROSS_COMPILE=arm-none-linux-gnueabi-
> I get boot image for Beagle Board rev A but i need image for rev B.
> How to configurate revision before compiling?

The image you have is fine.. .

Almost all "rev B"'s have the same gpio setting as the "rev A"'s... So
there's no way for u-boot to detect a "B" unless the gpio detection
routine was expanded to core id revision..

For the release of the Rev B boards, the issue of u-boot having a bug that caused newer revisions of boards to revert to pre-xM settings meant that it was easiest (had the best software experience) to not change the GPIO-based revision ID settings.  If you want to detect that you have a Rev B board (that doesn't require any software changes over Rev A), then you can simply detect the CPU revision.  Honestly, I don't know why it had to become Rev B, but I think that is the convention (CPU revisions causing board revision updates) and don't think it matters much either.

For xM Rev C boards, there was a change to the way the USB hub is powered, so the change to the GPIO-based revision ID settings became required.  Thus, you'll find that old MLO/u-boot/uImage won't work with the xM Rev C boards due to that bug with the software treating newer revision boards as pre-xM boards.  If you update the MLO/u-boot/uImage to newer versions, you'll find that software will work on both boards.

The patches in question are (placed here for my reference and soon to end up on a FAQ somewhere):

MLO (upstream): http://gitorious.org/x-loader/x-loader/commit/2efa178acd56d83c86210b5934895cfb9ea62125
u-boot (upstream): http://git.denx.de/?p=u-boot.git;a=commitdiff;h=f6e593bb1255d1e15201cb5dec8c95264489e729 (reports unknown version, but works)
kernel: http://gitorious.org/beagleboard-validation/linux/commit/bfca58987039791522d1821e0506f8a113a0c239 (looks like this one still needs to be cleaned up and submitted upstream -- any help is useful here)

Note that in the kernel patch, the polarity of the USB hub power enable signal is the same on pre-xM boards and xM boards post-C, whereas xM boards rev A & B have it reversed.

Regards,

--
Robert Nelson
http://www.rcn-ee.com/