[Qemu-devel] Re: How to get 1280x1024 display from guest running Xorg?

[Jano <alejandro@mosteo.com>]

Robin Atwood wrote:

> On Wednesday 21 Feb 2007, Ben Taylor wrote:
>> ---- Robin Atwood <robin@binro.org> wrote:
>> > This has been driving me mad! I have just installed Solaris 10 under Qemu
>> > and specified the Xorg server to be used. I created xorg.conf with
>> > xorgconfig and X started fine at 1024x768 using the Cirrus driver. When I
>> > edited xorg.conf to specify a 1280x1024 display, the Xorg.0.log file
>> > showed "no mode".
>>
>> You may have to define HorizSync and VertRefresh in the xorg.conf file.
>>
>> I have a nexenta alpha 6 with updates that just comes up in 1280x800 by
>> setting the HorizSync value in the xorg.conf.
>>
>> > Now, I
>> > have both Win XP and Plan 9 running at 1280x1024, so I booted up XP and
>> > poked around the "Display/Settings" dialog and determined XP was running
>> > the display at 1280x1024 at 43Hz interlaced and 16 bit colour.
>>
>> So you also need to define DefaultDepth in the xorg.conf file.
>>
>> > So, using the
>> > handy http://xtiming.sourceforge.net site, I generated a mode line like
>> > XP's and added it to the xorg.conf file. X refused the interlaced mode so
>> > I tried an uninterlaced one at 43Hz. That kind of worked but only
>> > rendered half the screen! Everything else I tried got rejected as "bad
>> > mode..."
>>
>> Since the virtual monitor doesn't specify EDID, it is unlikely to be able
>> to handle resolutions over the basic ones.  I know that a while ago (maybe
>> 18 months) I was able to get something like 1156x864 out of the adapter
>> with early versions of Solaris express.
>> .
>>
>> > So does someone have a magic modeline or xorg.conf to get Xorg going in a
>> > guest at high-res? There's another guy on the Linux-under-Qemu forum with
>> > the same problem hosting Ubuntu. I am using qemu 0.9, FWIW.
>>
>> Probably a combination of HorizSync/VertRefresh in the monitor section,
>> DefaultDepth in the Screen section, and a mode line, you might get what
>> you want.
> 
> Solved it, and it was so simple! There is a qemu CLI option "-std-vga" which
> causes an enhanced Bochs VGA adaptor to be emulated. So, specify that when
> you boot, use the VESA driver in xorg.conf and the default 1280x1024 mode now
> works.
> 
> From the man page:
> -std-vga
>  Simulate a standard VGA card with Bochs VBE extensions (default is Cirrus
> Logic GD5446 PCI VGA). If your guest OS supports the VESA 2.0 VBE extensions
> (e.g. Windows XP) and if you want to use high resolution modes (>=
> 1280x1024x16) then you should use this option.
> 
> I think this is a recent update because I recall looking at this option and
> deciding it was not what I needed. Or, I am going blind...

I don't know if this has been updated, but I tried it in 0.8.2 and it didn't
work at 1280x1024, at least not out of the box. Either it has been improved or
I did something wrong.