Re: OPENSTEP 4.2 vmware SVGA

[Frederic Stark]

[Sorry for the spam. I know that discuss-gnustep is not appropriate to 
talk about writing a driver for a proprietary system under a proprietary 
virtual machine]

Stefan Boehringer wrote:
> Hello Fred,

Hi,

> I guess you are going to become the hero of all the OPENSTEP veterans 
> ;-) (I'm one of the impatient and would appreciate receiving your code).

It is _really_ ugly for now (full of hard-coded values, half-baked tests 
and desesperate attemps, coded in a 640x480 OPENSTEP virtualized 
machine). It is surprisingly small (250 lines, mostly debug and dead 
code. Probably 20 real lines max). I  promise a less dramatic release 
this week-end (in the meantime, the ugly one is at 
http://www.chez.com/fstark/VMWareSVGA.tar.gz , source and binary. 
Supports only 1024x768 24bits. [sorry for the web-bugged ridden chez.com 
site, but I can't think of any better place to put it]).

> In principal vmware is supposed to support frame buffer access, i.e. it 
> runs without any additional vmware-graphics driver. I think it works at 
> least for windows. I have not tried Openstep on vmware yet, but does it 
> work seamlessly under VGA resolution?

Yes. And, if I understood the thing correctly, under windows, it can 
also work under VESA. But the OPENSTEP VESA driver request a mode (106h, 
IIRC) that is not supported by vmware.

> If so, I would rather have a closer look at your driver.

Well, there is so little to do in a framebuffer driver that I don't see 
what I could have done wrong.

>  >From what I heard from the list vmware Inc. seems to be very 
> cooperative (license donation). Perhaps the contacts used earlier could
> work again and some information of the exact way of "screen 
> virtualization" by vmware could be acquired.

I plan to post on the vmware newsgroup when I'll have enough information 
and a presentable semi-working driver.

> Personally I would hope for a direct access to the frame buffer in full 
> screen mode (as I understand it both the virtualization and XFree could 
> allow for direct access), but this is clearly beyond our control.

I hoped that too, but it don't seem to be the case (at least on my video 
hardware)

> I do not understand how you would like to force flushing.

There is a register command for that (ie: I can force the virtualized 
SVGA board to flush a part of the screen).

> If you remain
> in your virtualized machine, all you can do is modifying the frame 
> buffer and hoping for the virtualizer to reflect your changes properly. 
> If vmware doesn't this is clearly a vmware "bug".

Yes, but as OPENSTEP is not a supported system...

> Otherwise you have to
> cooperate with the virtualizing application (i.e. vmware) itself to 
> direct it to the rectangles to flush.

Yep.

Cheers,

--fred