On Apr 5, 2005, at 3:32 PM, Dan LaBell wrote:

>
> On Apr 4, 2005, at 9:57 PM, Tim Kelly wrote:
>
>> On Mon, 4 Apr 2005 21:35:55 -0400
>> Michael <macallan18@earthlink.net> wrote:
>>
>>>
>>> What kind of card is it ( besides sitting in the L2 slot ) - does it
>>> need any additional software to be recognized by MacOS? If so - does
>>> it leave anything funny in OF's nvramrc or something like that? If
>>> you're lucky this thing can be enabled with some OF voodoo ( Tim?
>>> You're the OF guru. )
>>
>> Dan LaBell clearly knows more than I do about OF and Forth. I do know
> Maybe, forth, but as far as the mac specific voodoo, I think you do.
> And openfirmware is ANS forth, while I learned Forth-83.
> The docs for sparc claim that they have switch-cpu, doesn't look like
> we do though.  Maybe try:
>   show-devs /cpus
> Also try:
>   sifting cpu
> One standout in the list is find-unused-cpu, also noticed a start-cpu1.
>
>
>> that OF does expect to be on one CPU only, so I don't think it's set 
>> up
>> to switch CPUs. I have a 7200 that used to have a Sonnet G3 upgrade
>> card
>> (which was horribly unreliable) and as far as I could tell, the switch
>> to the PCI card-based CPU only occured after the extension was loaded
>> by MacOS. If I had to guess, there has to be some write to a PCI
>> register that then turns the CPU on, and from there some renegotiation
>> of PCI bus mastering occurs or something that allows the second CPU to
>> become the primary one. The new CPU gets the same register contents as
>> the old one and resumes execution of the OS. Sort of a fork of the OS,
>> with the parent then turning off external interrupts on the old CPU.
>>
> What came with the upgrade in question?  An extension ? Or a firmware
> patch?
> If firmware, maybe they just patched mac-boot...
>
>

Just an extension, as far as I know. It's an OF2 machine, so nothing 
rewritable except the nvramrc, and there's nothing in there.
I'll check out those commands in a bit, as soon as it's done with the 
world build its currently working on.

  -Adam