[U-Boot] loading via jtag

E Robertson e.robertson.svg at gmail.com
Sat Jul 4 17:21:03 CEST 2009


On Thursday 02 July 2009 03:57:38 pm Frank Svendsbøe wrote:
> On Thu, Jul 2, 2009 at 3:32 PM, E Robertson<e.robertson.svg at gmail.com> 
wrote:
> > On Thursday 02 July 2009 02:22:16 am Frank Svendsbøe wrote:
> >> On Thu, Jul 2, 2009 at 6:10 AM, E Robertson<e.robertson.svg at gmail.com>
> >
> > wrote:
> >> > Hi All,
> >> > Has anyone used the JTAG like the BDI2000 to load u-boot onto a
> >> > at91sam9263? I've done it on other boards but some some reason the
> >> > code will not execute
> >> > from on board SDRAM. To avoid initializing the external memory via
> >> > jtag, I use the bootstrap code to do the setup then load u-boot and
> >> > run it.
> >> > For reason(s) I haven't figured out yet, the code will not external
> >> > memory. Has anyone done this before and can provide some help?
> >> > Thanks.
> >>
> >> How come you want to execute it from RAM? Is the board without flash?
> >> Could you instead replace the "bootstrap" loader with U-Boot?
> >>
> >> It the SDRAM controller is already setup, I guess you must recode U-Boot
> >> and tell it not to touch/re-initialize the memory controller...
> >>
> >> Btw, look at
> >> http://www.denx.de/wiki/view/DULG/CanUBootBeConfiguredSuchThatItCanBeSta
> >>rte dInRAM
> >>
> >> - Frank
> >
> > In this case, I believe things are a bit different. U-boot is not
> > relocated because the bootstrap already does this and the bootstrap does
> > all the init needed to set up ram (among other things). I'm tracking a
> > problem which is why I'm trying to run it from ram. I've done quite a bit
> > of modifications to the point where I believe this should work, but
> > apparently I may have overlooked something.
>
> Ok. The BDI makes it possible to debug U-Boot so that you can pinpoint
> where the problem occur. Have you tried that yet, and what exactly is the
> problem you observe?
>
> Try to be more specific, then some of the Gurus here may be able to help
> you. Good luck!
>
> - Frank

Thanks. I finally figured out what the problem is. I have s signal integrity 
problem on my SDRAM bus.



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