Re: Booting netbsd-GENERIC_MD on iMac G3 using ofwboot.xcf + genfb woes

[Michael <macallan1888%gmail.com@localhost>]

Hello,

On Tue, 20 Oct 2026 11:43:44 +0200
Sam van Kampen <sam%tehsvk.net@localhost> wrote:

> As for my original woes, I am happy to report that, with r128fb
> enabled, I was able to boot and install the system successfully! By
> default r128fb doesn't pick up my card, so it does require adding the
> PCI ID of the card to its match function (patch below). After that it
> was smooth sailing.

Well, r128fb has the PCI IDs of what I've been able to test with, so
I'll add yours.

> Now onto the next hurdle, which seems to be X. The r128 driver
> _should_ support this card.. but when I start the server I just get
> an unrecoverable blank screen...

I'd ssh into the iMac and start the Xserver by hand with -verbose 10,
that way you can see how far it gets. Setting a working video mode
might be somewhat difficult, I had a 1st generation iMac G3 many years
ago, and the built-in monitor is quite odd - it only works with a very
narrow range of line frequencies ( I forgot what it was, IIRC
1024x768@60Hz worked, other modes needed the frame rate bumped up to
land at the same line frequency ) and of course there was no EDID block
to be found either by DDC or in the device tree.
I suspect the same applies to all G3 iMacs, more or less.
So, in order to figure out what's going on please send me the machine's
ofctl -p output ( that will dump the device tree with properties ) and
your X -verbose 10 output. I suspect that Xorg's r128 driver just
doesn't setup any video mode the monitor can deal with, hence the black
screen.
Also, what exactly do you men by 'unrecoverable'? Did the machine crash
or does it still answer pings?

have fun
Michael