path: root/Documentation/fb/tridentfb.txt

Tridentfb is a framebuffer driver for some Trident chip based cards.

The following list of chips is thought to be supported although not all are
tested:

those from the Image series with Cyber in their names - accelerated
those with Blade in their names (Blade3D,CyberBlade...) - accelerated
the newer CyberBladeXP family  - nonaccelerated

Only PCI/AGP based cards are supported, none of the older Tridents.

How to use it?
==============

When booting you can pass the video parameter.
video=tridentfb

The parameters for tridentfb are concatenated with a ':' as in this example.

video=tridentfb:800x600,bpp=16,noaccel

The second level parameters that tridentfb understands are:

noaccel - turns off acceleration (when it doesn't work for your card)
accel - force text acceleration (for boards which by default are noacceled)

fp	- use flat panel related stuff
crt 	- assume monitor is present instead of fp

center 	- for flat panels and resolutions smaller than native size center the
	  image, otherwise use
stretch

memsize - integer value in Kb, use if your card's memory size is misdetected.
	  look at the driver output to see what it says when initializing.
memdiff - integer value in Kb,should be nonzero if your card reports
	  more memory than it actually has.For instance mine is 192K less than
	  detection says in all three BIOS selectable situations 2M, 4M, 8M.
	  Only use if your video memory is taken from main memory hence of
	  configurable size.Otherwise use memsize.
	  If in some modes which barely fit the memory you see garbage at the bottom
	  this might help by not letting change to that mode anymore.

nativex - the width in pixels of the flat panel.If you know it (usually 1024
	  800 or 1280) and it is not what the driver seems to detect use it.

bpp  - bits per pixel (8,16 or 32)
mode - a mode name like 800x600 (as described in Documentation/fb/modedb.txt)

Using insane values for the above parameters will probably result in driver
misbehaviour so take care(for instance memsize=12345678 or memdiff=23784 or
nativex=93)

Contact: jani@astechnix.ro