Re: cg14 vesa (modes) project on github

чт, 8 янв. 2026 г., 07:25 Bob Breuer <[email protected]>:

> On Wed, Jan 7, 2026 at 9:47 PM Andrew Randrianasulu
> <[email protected]> wrote:
> >
> >
> >
> > чт, 8 янв. 2026 г., 06:16 Bob Breuer <[email protected]>:
> >>
> >> On Wed, Jan 7, 2026 at 11:46 AM Andrew Randrianasulu
> >> <[email protected]> wrote:
> >> >
> >> > On Wed, Jan 7, 2026 at 8:40 PM Malte Dehling <[email protected]>
> wrote:
> >> > >
> >> > > Hi Andrew,
> >> > >
> >> > > I've only tested the prom on physical hardware, and I haven't been
> able to get qemu to work with an ss20 and original prom recently.  Would
> love to hear if you make progress on this!
> >> >
> >> > well, for me setting -cpu to something like
> >> >
> >> > "TI SuperSparc 50"
> >>
> >> As I remember, the Qemu SuperSparc II implementation doesn't support
> >> one of the features used by the original OBP roms.
> >
> >
> > May be filling qemu-upstream bug about it will help, eventually?
> >
> > I noticed that with original ROM -smp switch does not increase about of
> firmware-counted CPUs ...
> >
> >>
> >> >
> >> > work, at least i see logo and can enter probe-scisi.
> >> >
> >> > Note, this is more like qemu 9.2.50 as Artyom created it 9 months ago,
> >> > not really recent qemu git (10.x, 11.x)
> >> >
> >> > https://youtu.be/wCFBvzVCVMk - short vid of whole thing booting
> >> >
> >>
> >> I didn't notice that Artyom rebased my cg14 patches.  I also have a
> >> separate branch where I implemented the DBRI audio device.
> >
> >
> > Interesting, is this branch public?
>
> Yes, it's here:  https://github.com/breuerr/qemu/tree/dbri-pre2
> I think the audio output was clean with a Linux client but had popping
> with a netbsd client.
>

Thanks!


> >
> >
> >>
> >> > >
> >> > > IIRC, qemu has resolutions hard coded in, but I may be wrong about
> this.
> >>
> >> Is there any particular resolution that you are looking for?
> >>
> >> The emulated cg14 was flexible enough to handle any resolution that
> >> could be programmed.  However, the startup resolution is limited by
> >> the monitor ID bits.  The cg14_set_monitor_id() function translates
> >> the Qemu command line resolution to a monitor ID for a nearby OBP
> >> resolution.  In addition to 1152x900, the resolutions of 1280x1024 and
> >> 1600x1280 should also work by default.
> >
> >
> > In my case I was after not so much resolution per se, but was trying to
> avoid some strange emulated  TCX bugs, I can avoid most of them by running
> xcompmgr& in NetBSD but something still not 100% correct with cinelerra-gg
> and mplayer, colors are swapped in video output (plain X11, not xv), so I
> was hoping to see if emulated cg14 can sidestep this issue
> >
>
> Might be able to try with cg3, that thing had absolutely no
> acceleration, but it's 8-bit only.
>

I think 8bit does not really cut it for video ;)

https://mastodon.online/@Andrew_R/115756500366360503

at least without sophisticated dither ...

I ran same cinelerra-gg build  against NetBSD/macppc X server and it showed
correct colors in 24bpp there.



> Or if you need 24-bit color but the lack of SX is a problem,
> theoretically the SS10 supported cg14 without SX and it should be
> possible to hack that into qemu.
>
> >
> >>
> >> Bob
> >>
> >>
> >> > >
> >> > > Cheers,
> >> > > Malte
> >> > >
> >> > >
> >> > > On Wed, Jan 7, 2026, 9:31 AM Andrew Randrianasulu <
> [email protected]> wrote:
> >> > >>
> >> > >> On Wed, Jan 7, 2026 at 8:00 PM Andrew Randrianasulu
> >> > >> <[email protected]> wrote:
> >> > >> >
> >> > >> > Was looking for Sparcstation-20 proms to test with cg14 enabled
> qemu
> >> > >> >
> >> > >> > found this project;
> >> > >> >
> >> > >> > https://github.com/mdehling/cg14-vesa-mod
> >> > >> >
> >> > >> > https://github.com/artyom-tarasenko/qemu/ - branch cg14
> >> > >> >
> https://github.com/artyom-tarasenko/qemu/commit/1b1d8b87619e613b059766e6e54687b027fb6e3f.diff
> >> > >> >
> >> > >> >
> https://github.com/artyom-tarasenko/qemu/commit/b297821755e68381e7753d877a7912bebe9271d8.diff
> >> > >> >
> >> > >> > but device cg14 not on list so you need to start it like this:
> >> > >> >
> >> > >> > build/qemu-system-sparc -M SS-20 -g 1152x900
> >> > >> > cg14_realizefn 1152, 900
> >> > >> >
> >> > >> > Of course default openbios does not know how to output to that,
> so I'm
> >> > >> > trying this Sun PROM now ...
> >> > >>
> >> > >>
> >> > >> It tries to boot my NetBSD install but it faults somewhere along
> the way:
> >> > >>
> >> > >>  build/qemu-system-sparc -M SS-20 -g 1152x900 -bios
> >> > >> ~/Desktop/ss20-2.25.bin  -cpu "TI SuperSparc 50" -hda
> >> > >> /mnt/zip/home/guest/QEMU/sparc-netbsd-15g-compressed-r1.qcow2
> >> > >> cg14_realizefn 1152, 900
> >> > >> CG14: control register (0x5a) has unimplemented bits set
> >> > >> CG14: readb from reg 1000
> >> > >> CG14: writeb 0x00 to reg 1000
> >> > >> CG14: writeb 0x01 to reg 1000
> >> > >> CG14: readb from reg 1000
> >> > >> CG14: readb from reg 1001
> >> > >> CG14: writeb 0x01 to reg d
> >> > >> CG14: readl 00000000 from reg 20c
> >> > >> CG14: writeb 0x02 to reg 100
> >> > >> CG14: readl 00000000 from reg 20c
> >> > >> CG14: readb from reg 200b
> >> > >> CG14: readb from reg c
> >> > >> CG14: writeb 0x00 to reg c
> >> > >> CG14: writeb 0x02 to reg 100
> >> > >> CG14: readl 00000000 from reg 20c
> >> > >> CG14: readb from reg 200b
> >> > >> CG14: readb from reg c
> >> > >> CG14: writeb 0x00 to reg c
> >> > >>
> >> > >> https://mastodon.online/@Andrew_R/115854999356998946
>