Re: NetBSD/alpha on qemu-system-alpha

[Jason Thorpe <thorpej%me.com@localhost>]

> On Aug 19, 2021, at 12:30 PM, Remy van Elst <relst%relst.nl@localhost> wrote:
> 
> Hi Jason, thanks for your response, it clears up my questions.
> 
> I like to write about these sorts of things. Most of the AXPbox documentation was written by me and my site has stuff from 2006 and
> onwards. Legacy systems have a special place, especially DEC related.
> I did a writeup of TSS/8, WPS-8 and more regarding the PDP-8, VAX, Alpha
> and OpenVMS are in the same category. I do love playing with NetBSD, after installing the Alpha build, I also spun up a Virtualbox instance. Got XFCE and Clion running, so I might even consider switching my regular desktop over, since Clion and GCC are the only things I really need for my dayjob. pkgsrc seems to be a great system as well, I'm learning and discovering so much, just because of your work on the Alpha
> emulation.
> 
> Would it be possible to provide an SRM to qemu, like with AXPbox? (http://raymii.org/s/inc/downloads/es40-srmon/cl67srmrom.exe) / (https://github.com/lenticularis39/axpbox/wiki/OpenVMS-installation-guide)? The wiki page of qemu is quite sparse on alpha information.

Alas, no.  At least, not without major changes to Qemu.

In the Alpha architecture, one of the functions of PALcode is to abstract away some of the implementation details of the CPU from the operating system.  Qemu, to some extent, takes advantage of this in that the Qemu Alpha CPU emulation is not 100% "EV68".  Qemu, in fact, presents a new type of Alpha CPU to the software environment with its own set of internal processor registers.  Qemu's PALcode relies on this for start-up, exception handling, etc.  A real DEC EV68 PALcode would not work on Qemu.

> Regarding the disk IO, I can see with iostat that there is a lot of activity (when executing a gtk-update-icon-cache in another terminal),
> but I'm not familiar enough with netbsd to do more extensive monitoring.
> strace is not available as a binary package and pkgsrc source compilation needs kernel sources, I'm not sure how to get more information on what happening.

Yah, no worries, it's almost certainly what's going on.  I have a local patch that makes VirtIO work, but am still awaiting feedback on it from the Qemu folks.  That would help the situation considerably.

> I do want to, again, say thank you for your effort regarding alpha and qemu. It's giving me a lot of pleasure, playing around and discovering NetBSD.

You are most welcome ... I'm glad folks are having fun with it!

-- thorpej