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

Wolfgang Denk wd at denx.de
Tue Aug 17 13:43:15 CEST 2004


In message <877aabc404081704266d856f38 at mail.gmail.com> you wrote:
>
> > This is no problem at all. There are even boards without any flash at
> > all (for example, the PN62 board has no flash, and the  U-Boot  image
> > gets loaded into RAM over PCI).
> 
> 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.

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."




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