New virgefb driver (for CyberVison64/3D)

The new virgefb driver can initialize the CV3D board. This means that you do not have to switch the resolution under AmigaOS to the resolution you want to use with Linux. But it also means, you have to pass correct video parameters to make the kernel boot. And it should now be possible to use amiga-lilo on CV3D based machines (untested).

Here comes a list of video options that I have used on my (ZorroII) box:

amiboot -k vmlinuz root=/dev/sda4 video=virge:virge8
amiboot -k vmlinuz root=/dev/sda4 video=virge:640x480-8
amiboot -k vmlinuz root=/dev/sda4 video=virge:800x600-8
amiboot -k vmlinuz root=/dev/sda4 video=virge:1024x768-8
amiboot -k vmlinuz root=/dev/sda4 video=virge:1280x1024-8

Selecting the resolution during boot

All video options have to start with video=virge:, parameters follow after the colon.

You can use virge8 or virge16 to get a standard 8 (or 16) bit mode, currently this is set in the source to use the 800x600 resolution.

You can specify the resolution and depth as in XRESxYRES-DEPTH. The resolutions supported during boot are: 640x480, 768x576, 800x600, 1024x768, 1152x886, 1280x1024, 1600x1200.
Resolutions 1024x768 and higher can also be used as interlace modes (append an i after the depth).
Also supported is one double scan mode at 320x240, ie 320x240-8d.
The supported depths are 8, 16 and 32 (32-bit not tested on ZorroII).

Changing the resolution (running system)

The vertical refresh frequency might not be what you want after booting (or starting X11) with the new driver. This may also depend on whether you got the source from Ken, or if I had my hands on it, using slightly larger fV than Ken (and ones which do not cause the OSD of my monitor to become flaky). However, the good news is, you can use fbset to set the resolution and fV you want. A few examples:

fbset 1024x768-75 # resolution of 1024x768 with fV of 75Hz
fbset -a 800x600-80 # switch all consoles to 800x600 with 80Hz

To change the resolution for your X11 display, you should consult /usr/doc/xserver-fbdev/README.Debian.
Using openvt -c 7 fbset 1280x1024-60 (for vt 7) is reported to work when you call it (as root) just before startx.

For xdm, this was reported to work:

"openvt -c 7 -- fbset " (assuming that X is on vt7) in /etc/init.d/xdm
just before the X server is actually started.

You can also change the resolution within a running X "on the fly" by ctr-alt-+ (or -) provided your XF86Config is configured properly.

   SubSection "Display"
        Depth       8  
        Modes       "1024x768" "800x600" "640x480"
        Virtual     1024 768

Besides the Modes, you also have to supply a Virtual resolution (currently only tested with X 3.3.6).

Christian T. Steigies

Last modified: Mon Jan 15 18:12:38 CET 2001