On 09/10/08 11:19 +0100, Stephen Crocker wrote: > Kevin O'Connor wrote: > > On Mon, Oct 06, 2008 at 08:32:15AM -0600, Jordan Crouse wrote: > >> On 04/10/08 21:59 -0400, Kevin O'Connor wrote: > >>> I'm not an expert on VGA, but I think it may be possible to implement > >>> a bare bones vgabios with only a couple of chip specific functions > > [...] > >> Not just a possibility - but a certainty. Geode could be ported in a > >> matter of hours. > > > > Hi Jordan, > > > > I've spent some time taking a closer look at this. The bochs vgabios > > has a large number of in/out calls. If the geode vga doesn't natively > > emulate the legacy in/out ports then I think there is a fair amount of > > work to port bochs vgabios to geode.
I apologize - I spend a lot of my time hacking on the graphics engine, but I forgot all the other baggage that VGA brings with. > I have been looking at the Geode LX databook and on page 303, it lists > the standard VGA I/O ports (3CC, 3C2, 3BA/3DA etc.) which I had > previously assumed were emulated in the VSA. If they are indeed > implemented in hardware, it should be able to act as a standard VGA > device. However, this would make me wonder what the VGA emulation VSA > is for. The VSA is there primarily to trap 0x3c2 and to implement a few other extended functions. There is a document on our developer-only website that describes this, I have asked that we release it to the public. > If they are software I/O ports implemented in the VSA, an alternative > would be to make an open-source VGA emulation module for OpenVSA. > Unfortunately, my resources are too limited to attempt this task. Especially considering that OpenVSA itself needs a lot of work. > Just as a matter of curiosity, what is the licensing issue surrounding > the VGA emulation code? I understand that it is not open-source but is > it available as a binary? The VGA BIOS itself has licencing restrictions on it. The VSA emulation doesn't, but since we never planned on supporting VGA in the first place, it was a non-starter. The infrastructure is in place in the VSA code, but the actual mode switching isn't. Jordan -- Jordan Crouse Systems Software Development Engineer Advanced Micro Devices, Inc. -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
