[Qemu-devel] NT4 white mouse pointer using Cirrus 5446 driver under 0.9.1

[Qemu-devel] NT4 white mouse pointer using Cirrus 5446 driver under 0.9.1

[Mark Cave-Ayland]

Hi there,

I've been using qemu 0.9.1 to run an NT4 installation as a guest, and 
I'm having a problem with the mouse pointer within the NT4 guest 
appearing as a white square.

During the initial installation, NT4 uses the standard MS VGA driver 
which only supports 16 colours. Using this driver, the mouse pointer 
appears to work as normal. When I change the video driver in NT4 to use 
the Cirrus 5446 driver (in order to use a 1024x768 display in 256 
colours), the guest screen appears without any problems, but the mouse 
pointer always appears as a white square.

Can anyone explain why this is happening? I can provide some debug 
information if people can point me in the right direction.


Many thanks,

Mark.

-- 
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
http://www.siriusit.co.uk
T: +44 870 608 0063

Re: [Qemu-devel] NT4 white mouse pointer using Cirrus 5446 driver under 0.9.1

[Carlos A. M. dos Santos]

On Wed, May 21, 2008 at 11:27 AM, Mark Cave-Ayland
<mark.cave-ayland@siriusit.co.uk> wrote:
> Hi there,
>
> I've been using qemu 0.9.1 to run an NT4 installation as a guest, and I'm
> having a problem with the mouse pointer within the NT4 guest appearing as a
> white square.
>
> During the initial installation, NT4 uses the standard MS VGA driver which
> only supports 16 colours. Using this driver, the mouse pointer appears to
> work as normal. When I change the video driver in NT4 to use the Cirrus 5446
> driver (in order to use a 1024x768 display in 256 colours), the guest screen
> appears without any problems, but the mouse pointer always appears as a
> white square.
>
> Can anyone explain why this is happening? I can provide some debug
> information if people can point me in the right direction.

It seems that you are running out of colormap entries. Try to use 16
bits per pixel.

-- 
Carlos A. M. dos Santos

Re: [Qemu-devel] NT4 white mouse pointer using Cirrus 5446 driver under 0.9.1

[Mark Cave-Ayland]

Carlos A. M. dos Santos wrote:

>> Can anyone explain why this is happening? I can provide some debug
>> information if people can point me in the right direction.
> 
> It seems that you are running out of colormap entries. Try to use 16
> bits per pixel.


Hi Carlos,

Thanks for the hint. I've tried 8bpp and 16bpp, but it doesn't make a 
difference at all :(

After some experimentation here, I'm wondering if it is some kind of 
quirk within the NT4 driver related to alignment issues within the qemu 
code. The server for this qemu instance is running 32-bit Debian etch 
with 0.9.1, and I always see a white pointer whenever I connect. 
Interestingly though, I temporarily mapped the NT4 partition to my local 
laptop which is 64-bit Debian lenny with 0.9.1, and the mouse pointer 
appears correctly! So it appears that this could be a 32/64-bit related 
issue?

On another note, I have now managed to get the mouse pointer appearing 
correctly on the original 32-bit server by using the ReactOS video 
drivers here: http://www.bearwindows.boot-land.net/vbemp.htm instead of 
the Cirrus drivers. Thus I have a found a cure that works for me, but it 
looks like I am not the only person to experience this issue: 
http://www.debian-administration.org/users/ajt/weblog/115.


ATB,

Mark.

-- 
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
http://www.siriusit.co.uk
T: +44 870 608 0063