[Simh] NetBSD 5.1 on MicoVAX 3900 boot error

[Mark Pizzolato]

On Friday, April 21, 2017 at 10:57 AM, Anders Magnusson wrote:
> Den 2017-04-21 kl. 19:14, skrev Mark Pizzolato:
> >
> > OK.  So, the difference in boot output on the simh v3.x version is:
> >
> >          rx0 at mscpbus1 drive 3: RX50
> >          qe0 at uba0 csr 174440 vec 764 ipl 17: deqna, hardware address
> 08:00:2b:23:52:2f
> >
> > while on the failing simh v4.x version it is:
> >
> >          rx0 at mscpbus1 drive 3: RX50
> >          qt0 at uba0 csr 174440 vec 764 ipl 17panic: Segv in kernel mode: pc
> 801feeb5 addr 1c
> >          Stopped in pid 0.1 (system) at  netbsd:upcallret:       function
> "upcallret()", e...
> >
> > As it turns out, on both versions of simh, the XQ device defaults to
> emulating a DELQA-PLUS
> > (aka DELQA-T).  Some changes were made in the XQ device simulation over
> time which now
> > allows the NetBSD driver to detect the device as an DELQA-T instead of
> merely a DEQNA and
> > it now is using the qt driver instead of the qe driver.  The NetBSD qt driver
> seems to have
> > some sort of bug and/or incompatibility with the DELQA-T device simulation
> which is
> > demonstrated as the crash you see.
> >
> Note that the delqa-t driver comes from 2.11BSD.  If it fails with
> NetBSD but not 2BSD I may have
> introduced some bug when porting it over.  It do work very well on real
> hardware though.

That is why I asked about what driver ends up getting used in later NetBSD versions.  
If it is the qt driver, then I'm not worried about fixing anything.  If it is not the qt 
driver, then there is something to fix to get the device probe happy...

- Mark