[U-Boot-Users] Re: Re: mtmsr causes an exception (it was "Problem wi

llandre r&d at wawnet.biz
Wed Apr 23 18:19:10 CEST 2003

Thanks to Stefan Roese, I think I definitely solved this bothering problem. 
It seems the cause is a "hidden" memory access to an invalid location (for 
example to an address in the SDRAM region before memory controller has been 
initialized). When stepping through the MTMSR instruction, it seems GDB 
generates some of these accesses even if the user does not perform a memory 
read (I suspect such an access is performed to the address contained in the 
EVPR register).
I solved the problem by initializing the SDRAM controller even if the code 
to be debugged does not need it. This way all accesses to locations ranging 
from 0x00000000 to 0x08000000 are "well-behaved" and don't cause any exception.


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