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

Wolfgang Denk wd at denx.de
Mon Aug 16 22:21:19 CEST 2004

In message <cfqlq9$1d9$1 at sea.gmane.org> you wrote:
> I have u-boot working on a custom board based on the MV64360 with a PPC
> 750GX processor. I've set the autoboot timeout to 3 secs, with the bootcmd
> to 'go 0x40004'. I have a 'serial_getc' in main_loop so that I can transfer
> a binary to the 40004 mem. location using a PCI interface via the host
> machine.

Ummm.. what _exactly_ are you  doing?  What  has  a  "serial_getc  in
main_loop"  to  do with a PCI transfer to memory? and why do you have
to  do  such  modifications  at  all  when  all  can  be  done  using
envrionment variables?

> On timeout, u-boot tries to transfer control to the binary, but it seems
> there's some problem:

What exactly is the contents of the  memory  at  0x00040004  at  this
time? [and how can you be sure about this?]

> Also, can this be due to some caching? It should not, 'cos there shouldn't
> have been any access to this location earlier for the data at that location
> to be cached, but one possibility that I can think of right now.

If there was no access to this location  earlier,  then  how  do  you
think this location could contain executable code?

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
Remember that Beethoven wrote his first symphony in C ...

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