V2 RC10 via OE cross compile to OMAP3

[Sascha Hauer]

On Sat, Dec 12, 2009 at 10:19:41PM +0100, Marc Kleine-Budde wrote:
> Freeman P. Pascal IV wrote:
> > On Sat, 2009-12-12 at 12:54 +0100, Sascha Hauer wrote:
> >> On Thu, Dec 10, 2009 at 10:50:49PM -0700, Freeman P. Pascal IV wrote:
> >>> Hello,
> >>>         
> >>>         I'm trying to build RC10 for use on an Archos 7 internet media
> >>>         tablet.  The idea is to load u-boot V2 during the stage 3 boot
> >>>         instead of the original modified initramfs image from flash.
> >>>         I could then select which kernel and root file-system I use to
> >>>         boot the rest of the way.
> >>>         
> >>>         On top of this, I am trying to use an OpenEmbedded overlay
> >>>         that is based on the SDE (Special Developer Edition) release
> >>>         provided by Archos.  I want to use the cross compiler
> >>>         generated by the OE image in preparation for generating a
> >>>         recipe for doing the same when building my release images.
> >>>         
> >>>         With a bit tweaking, I have been able to generate binaries for
> >>>         RC10 for my Archos 7 and my BeagleBoard.  Both using the their
> >>>         own cross compiler tools generated by their separate OE
> >>>         projects.  This is using the patches for the OMAP3 found on
> >>>         this list. 
> >>>         
> >>>         From what I have read, I should be able to copy the
> >>>         executable
> >>>         ELF binary (not the .bin file) on to my respective devices and
> >>>         run it to test if it works.  When I do this, I get an "Illegal
> >>>         instruction" error.
> >>>         
> >>>         Could I get someone to confirm or deny my assumption about
> >>>         being able to test the elf binary on my devices?  Should I be
> >>>         compiling the sandbox version for my devices instead of the
> >>>         platform/board specific versions?
> >> You cannot run the ELF file on your devices, you have to use the bin
> >> file for this. The ELF file is only usable for the sandbox target in
> >> which case you run it on the machine you compiled it on.
> >>
> >> Sascha
> >>
> > 
> > Using the elf executable was really only a test to see if I had the
> > compiler settings correct.  If it started up and got to a prompt I was
> > going to be satisfied.  If it ran I could have some confidence it would
> > do so once I moved into flash where my existing boot-load could execute
> > it.
> > 
> > The problem is that the Archos 5 and Archos 7 are consumer devices with
> > no exposed JTAG and no obvious serial port.  There is a recovery chain,
> > but it requires that the original stage 0 boot-loader, stage 1
> > boot-loader, and recovery flash image are all functional.  I want to
> > preserve the original boot-loader, but use V2 to intercept loading the
> > normal kernel and allow for pre-boot operations (such as selecting an
> > alternate kernel, rootfs, or kernel arguments).  The whole idea is to
> > try avoid bricking the device while still allowing some pre-boot
> > flexibility.
> > 
> > Does anyone have any suggestions how to test and possibly debug without
> > GDB support within the restrictions I listed above?  Qemu-omap3 could be
> > an alternative, but I would have to emulate enough of the Archos
> > hardware to make it possible.
> 
> If it's possible within your existing boot environment to load the
> u-boot-v2.bin into your RAM and start it, then try it. The same
> u-boot-v2 image can be started from RAM, NOR and NAND.

AFAIK the Beagle Board does not have NOR flash. I tried booting it from
SD card using the instructions on some beagle board website. I just
replaced the U-Boot-v1 binary with a barebox binary. I had some output
on the coonsole, but it crashed at some point. I didn't investigate
further yet.

Sascha



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