What is aty128fb?

This is a driver for a graphic framebuffer for ATI Rage128 based devices on Intel and PPC boxes.

Advantages:

  • It provides a nice large console (128 cols + 48 lines with 1024x768) without using tiny, unreadable fonts.
  • You can run XF68_FBDev on top of /dev/fb0
  • Most important: boot logo :-)

Disadvantages:

  • graphic mode is slower than text mode… but you should not notice if you use same resolution as you used in textmode.
  • still experimental.

How to use it?

Switching modes is done using the video=aty128fb:<resolution>… modedb boot parameter or using fbset program.

See modedb default video mode support for more information on modedb resolutions.

You should compile in both vgacon (to boot if you remove your Rage128 from box) and aty128fb (for graphics mode). You should not compile-in vesafb unless you have primary display on non-Rage128 VBE2.0 device (see What is vesafb? for details).

X11

XF68_FBDev should generally work fine, but it is non-accelerated. As of this document, 8 and 32bpp works fine. There have been palette issues when switching from X to console and back to X. You will have to restart X to fix this.

Configuration

You can pass kernel command line options to vesafb with video=aty128fb:option1,option2:value2,option3 (multiple options should be separated by comma, values are separated from options by :). Accepted options:

noaccel do not use acceleration engine. It is default.
accel use acceleration engine. Not finished.
vmode:x chooses PowerMacintosh video mode <x>. Deprecated.
cmode:x chooses PowerMacintosh colour mode <x>. Deprecated.
<XxX@X> selects startup videomode. See modedb default video mode support for detailed explanation. Default is 640x480x8bpp.

Limitations

There are known and unknown bugs, features and misfeatures. Currently there are following known bugs:

  • This driver is still experimental and is not finished. Too many bugs/errata to list here.

Brad Douglas <brad@neruo.com>