2010/6/6 Blue Swirl <blauwir...@gmail.com>: > On Sat, Jun 5, 2010 at 11:10 PM, Bob Breuer <breu...@mc.net> wrote: >> Blue Swirl wrote: >>> but again: should we have a new machine with cg14 or >>> some switch to select TCX vs. cg14? >>>
Why not just probe for both devices? OpenBIOS has the intention to run one day on a real hardware, doesn't it? >>> Maybe the recently proposed machine subtype patches could help here. How is the graphic card different from cpu or a disk drive? >> Well, let's try to figure out a method of selecting the framebuffer >> type. I'll try to list some of the options, even if they might be >> ridiculous. >> >> 1) Use the -vga option. I know TCX and cg14 are not vga, but I think >> it's the closest existing command line option available. >> >> 2) Switch based on the -g WxH option. At the moment, the TCX emulation >> doesn't really handle anything other than 1024x768, so switch to cg14 >> for other resolutions if supported. >> >> 3) Use some other existing command line option, -device, -set or >> -global? Might work, but the syntax may not be easy to remember. > > We don't have an equivalent of -chardev, -netdev and -drive for displays. I guess only cause the other emulated platforms don't have that much of choice (yet). Why not use just the generic -device option? >> 4) Machine subtype. >> >> 5) New command line option. Anything above might be better. >> >> 6) New machine type. Is it a big enough feature to demand it's own >> machine type? Maybe, but see next option. >> >> 7) Select as default video for SS-20. The SS-10 and SS-600MP are >> already very similar. This would allow for some differentiation between >> the machines, but there could still be an option to switch back to TCX. >> Note that TCX was really only available for the SS-4 and SS-5. >> They are similar in qemu. But it's rather a bug than a feature. The real SS-600 is much more complex VME-bus machine. >> >> Is there anything else that I missed? > > Combined 7 & 6: make cg14 default for SS-20, add a deprecated > compatibility machine for SS-20 with TCX. > >> >> I'm going to go ahead with option 2 in the short term. I'm inclined to >> narrow it down to options 1, 4, and 7. I know that 7 would have >> backwards compatibility concerns. The cg14 seems to have at least the >> same capabilities as TCX so there shouldn't be any loss of >> functionality. Even though SS-20 is not the default machine, do you >> know of any OS that works with the sun4m implementation today but >> doesn't have a cg14 driver? Possible downside to cg14 for video is that >> any "acceleration" is handled by the SX pixel processor which has no >> available documentation. TCX also has some amount of unimplemented >> acceleration. > > It would be nice to use some basic device with well defined > acceleration or just a frame buffer as default. > AFAIK the open source OSes don't use the cg14 acceleration anyway. So we'll only have potential problems with Solaris and NeXTStep here. -- Regards, Artyom Tarasenko solaris/sparc under qemu blog: http://tyom.blogspot.com/