G5 support ( was Re: Booting on a Powerbook6,8 (was Re: Installing 8.0 on a Powerbook6,8))

[Michael <macallan%netbsd.org@localhost>]

Hello,

On Tue, 16 Feb 2021 00:36:12 -0500
Австин Ким <freennix%gmail.com@localhost> wrote:

> Please forgive me for not being a PowerPC developer, for being
> completely ignorant of the state of PowerPC support on the various
> BSDs, and for posting completely off-topic, but I have Apple Power
> Mac G5s I’ve been dying to get back on to and was wondering if anyone
> had a couple minutes to summarize briefly for us total novices out
> there:

Well, I'll do my best.

> 0.  What is the state of 64-bit support for IBM PowerPC 970-based
> Apple Power Mac G5s in {Net, Open, Free}BSD at the moment?  Last time
> I attempted to run any of the BSDs on my Power Mac G5s 5+ years ago,
> FreeBSD was the only one supporting running in full 64-bit mode; has
> the situation changed since then with either NetBSD or OpenBSD?

Lacking 64bit pmap. We run on a few models ( namely the ones I have - a
dual core 2GHz PCIe and a 2x 970FX PCI-X ) in 32bit bridge mode but
hardware support is on par with other machines. As in, SATA, ethernet,
audio, X11 etc. all work. The r5xx radeon in the PCIe model has no
accelerated X support because the Xorg driver relies on BIOS calls to
program CRTCs ( and so does DRM, so getting that to work isn't going to
help here either ) but wsfb works.
Supporting more models is mostly a matter if getting the hardware into
the right hands - fan control is by software only, and differs
significantly between models so adjustments are most likely needed.
Basically it's a bunch of semi-random i2c sensors that all need their
own drivers ( I added a few to make my G5s work ) and another part that
controls fan speeds based on readings from those sensors ( two
different ones so far ). Mapping sensors to zones and fans is not as
straight forward as it looks like, and OF isn't all that helpful there.

> 1.  In the BSDs that do support running in full 64-bit mode on
> PowerPC 970-based Power Mac G5s, does anyone know the state of
> multi-core/multi-processor support in the various BSDs?  The last
> time I tried NetBSD 5+ years ago, I could only get it to run in
> 32-bit “bridge” mode, and the default kernel only supported running
> on a single core in a Power Mac G5 Quad.  And finally,

SMP works on mine and I made things work on a 2x 970MP machine a while
ago ( the old SMP code didn't really support more than 2 CPUs, now it
does ).

> 2.  If it be the case that FreeBSD is the only *BSD that supports
> running a multi-core/multi-processor kernel in full 64-bit mode on
> PowerPC 970-based Power Mac G5s, why couldn’t (or why wouldn’t) it be
> easier to port their 64-bit PowerPC 970 MP kernel to NetBSD or
> OpenBSD?  (* by which I just mean their MP kernel, not specifically
> the 970MP processor variant)

The kernel guts are quite different, I'm not sure what exactly you mean
by 'porting their kernel'.

have fun
Michael