Till Straumann strauman at slac.stanford.edu
Thu Mar 3 20:17:52 UTC 2005

Peter Dufault wrote:

> On Mar 2, 2005, at 8:58 PM, Till Straumann wrote:
>> I don't think 'hot adding' is needed or in any way easy to do. AFAIK 
>> you rely on MOTLoad [or whatever it's called]
>> to perform the PCI configuration and the firmware is not going to 
>> support any 'hot adding' [hot == while system
>> is powered-on / running].
> Considering how the cards mount on the VME card, hot adding is 
> definitely an intellectual exercise only in relation to the MVME5500.
>> OTOH, if a DEC21150 is plugged into the [cold] system and powered up, 
>> MOTLoad will configure PCI
>> and you'll end up with 4 segments in total, the 1GHz ending up on 
>> segment 3.
> I don't think MOTLoad is that smart.  When I add a PMCSPAN (DEC21150) 
> with cards in it, MOTLoad displays the DEC21150 but doesn't show 
> anything about the devices on it, though it displays the devices on 
> BUS0 and BUS1. The manuals sure sound as if everything is hardwired in 
> place in the topology I showed in my ASCII art.  If there is a way to 
> set everything up with solder I wouldn't be surprised to find out that 
> is how it is configured.
> If anyone adds a bridge device off the PMCSPAN they'll have to plan to 
> get the code in powerpc/shared working to setup the bridge and 
> downstream devices.

Ouch - this is quite a task! Hopefully some pieces could be stolen from 


> Peter Dufault
> HD Associates, Inc.

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