[U-Boot] [PATCH v2] ppc4xx: Add Sequoia RAM-booting target

[Stefan Roese <sr@denx.de>]

Hi Wolfgang,

On Monday 11 May 2009 12:21:23 Wolfgang Denk wrote:
> > Here the commands to load and start this image from the BDI2000:
> >
> > 440EPX>load 0x1000000 /tftpboot/sequoia/u-boot.bin
> > 440EPX>go 0x1000000
>
> I assume you used "reset halt" before?

Yes, sure.

> > Please note that this image automatically scans for an already
> > initialized SDRAM TLB (detected by EPN=0). This TLB will not be
>
> And what happens when the TLB is not correctly set? Will we get a
> useful error message then?

No. SDRAM needs to work correctly so that this RAM-booting version can 
function. And for this the MMU needs to be configured and the SDRAM controller 
setup correctly. If this is not the case and SDRAM is not working from the 
debugger then we have no chance to load this image without problems (verify 
will most likely fail) or run it.

> > cleared. So your debugger should configure the SDRAM TLB correctly
> > (as done in the standard Sequoia BDI init script).
>
> Well, standard procedure is to boot using "reset run"; I think you
> should add the "reset halt" step to the documentation above - just to
> be sure.

Yes good idea. I'll update the commit text and resubmit.

Best regards,
Stefan

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