Re: cg14 vesa (modes) project on github

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!

IIRC, qemu has resolutions hard coded in, but I may be wrong about this.

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
>