[Simh] NetBSD 5.1 on MicoVAX 3900 boot error

[Anders Magnusson]

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.

-- Ragge