AlphaStation 200 NVRAM Problem

Robert Jarratt robert.jarratt at ntlworld.com
Sun Apr 24 13:03:50 CDT 2016


> 
> 
> From what I read the 3000 is a slightly earlier generation, not sure how
close
> it will be. Sounds like a good idea to get it going anyway. The thing I am
> struggling with at the moment is getting sys$crmpsc_pfn_64 to work so I
can
> use C to test the NVRAM. I seem to have a problem with the service writing
> back the address and length, but I don't yet know why.
> 

My program to test the NVRAM is not going well. When I try to write to what
I think is the flashbus index register, I kill the machine stone dead. I'd
just like to validate my approach, see if it makes sense:

The docs says the index register is at 0x1.0000.0000 (physical I assume). On
the assumption that the Alpha has an 8K page size that means the Page Frame
Number for the physical page will be at 0x8.0000. So I am using
sys$crmpsc_pfn_64 to start at that PFN. Correct? When I get the address back
from the system, that is actually the address of the index register, because
it is right at the start of page, so that is the address I access from my
code.

I was also unsure which region to use and I have tried P0 and P2, P2 seemed
to not crash the machine but would give me ACCVIO instead, except that in my
latest test P2 also crashed the machine. I am also specifying USER mode.

I can post the code if that helps.

Any ideas where I am going wrong here?

Thanks

Rob



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