MVME2304 Exception 3

gregory.menke at gregory.menke at
Mon Aug 18 16:45:53 UTC 2003

Joel Sherrill writes:
 > Paul D Jines wrote:
 > > Hello -
 > > 
 > >    We are trying to run RTEMS on a MVME2304-0143
 > > and are experiencing Exception 3 errors.  Any help or
 > > advice anyone could give would be greatly appreciated.
 > Isn't exception 3 a protection violation?  If so, then
 > I would be betting on an access to an invalid address.
 > My quick perusal of the documentation for a different
 > PowerPC model hints that it is more likely to be a write
 > since it could also be to a read only region of memory.

Exception 3 is a mmu error.  At least the motorla_shared powerpc bsp's
use the mmu to create a flat memory model where accesses outside the
range will throw this exception- null pointers, corrupt pointers that
kind of thing.

This suggests some kind of bsp error.  Could the OP please post the
register dump?  Its often possible to find what was running when the
exception is thrown, and is also helpful to know if it always happens
in the same place.


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