[U-Boot-Users] decoding 'program check exception trap'

Amit Shah shahamit at gmail.com
Tue Aug 17 13:59:37 CEST 2004

On Tue, 17 Aug 2004 13:43:15 +0200, Wolfgang Denk <wd at denx.de> wrote:
> > Hey WD, can you explain a bit on how you actually did this? The
> > preboot command copies something from PCI. How / when do you write to
> > the SDRAM over PCI? Did you do this through interrupts? Or was it
> > something else?
> In our case this was different. The system is  a  standard  PCI  card
> which sits in a PC. Some software on the PC will initialize the card,
> holding  the processor in reset. It will then upload the U-Boot image
> into SDRAM, and then release the processor on  the  card  which  will
> boot  U-Boot  from  the location in RAM, which then in turn will load
> and boot Linux.

My situation is a bit similar as well. I too have a PCI card. However,
we do have flash, so I use u-boot to initialize the SDRAM and UART on
the board. After this is done, some binary (evenutally, a uImage) is
to be loaded and run. How to synchroize these things? How to stop
u-boot so that image from the PCI can be transferred? Better would be
to interrupt the host, and the driver then signals some userspace
program to transfer the image. After this, signal the MV64360 that the
binary is loaded, so that u-boot can then continue and transfer
execution to the binary / uImage.

Is this too murky?


> Best regards,
> Wolfgang Denk
> --
> Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
> Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
> Quote from the Boss... "I didn't say it was your fault.  I said I was
> going to blame it on you."

Amit Shah

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