Re: netbsd-5.1 cpu probe/attach for 11/7xx?

[Johnny Billquist <bqt%softjar.se@localhost>]

On 2011-06-25 21:35, der Mouse wrote:
> > Older VAXen don't really have a CPU attach function.  There can only
> > be one CPU, and it is implicitly already attached.
>
> NetBSD/vax doesn't support the 782?  And I suppose the George Gobel's
> hack-job would be dreaming?

Right. The 782 is not supported. It is in fact rather tricky, if we were 
ever to support it, since it's not an SMP machine.
The second CPU acts as a slave to the first one. They are not equal. The 
second CPU can only do computations, and have no I/O attached to it.

> > So, there is no cpu probe code being done (or needed) for an 11/780,
> > nor any other Unibus VAX.
>
> I thought the 780 was SBI-based, with Unibus (and Massbus) hanging off
> the SBI.  Am I misremembering?  It _has_ been quite a while.

He. Of course someone should catch me in that lie... :-)
Yeah, the 11/780 have an SBO as the system bus, and then one or more 
Unibus adapters (and massbus adapters) attached to the SBI, along with 
memory.

There is in fact no VAX which have a Unibus as the native bus. The 
closest would be the uVAX I, which have the Qbus as the system bus. But 
that's the only one.

But I don't really know a good way to describe all the early VAXen with 
a common name, since they are so different. But it's all machines before 
VAXBI came, when actual MP VAXen first showed up.

VAXBI machines should have a CPU attach function somewhere, although I 
have not checked the code for those machines out.

        Johnny

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol