trident is a family of the X.Org graphics drivers for Trident graphics cards. This article details how to configure the kernel and your userspace in order to use the trident (tridentfb) driver.
Full Documentation can be found under /usr/src/linux/<your_kernal_name_here>/Documentation/fb/tridentfb.txt
You need to activate the following kernel options, note that you don't need to enable AGP Support if your card doesn't sit in a AGP slot:
Unknown IRQ microcode needed for Trident graphics support at this time, since the Kernel driver (tridentfb) should support most functions for Trident cards. Unknown KMS details (may not work without it?).
Make sure firmware for your model (check available ones in /lib/firmware/trident) is included in kernel:
Below is a list of the firmware files needed for each family of cards:
No known firmware files are needed for any particular Trident card at this time.
Framebuffer (GRUB or LILO)
Portage uses the variable VIDEO_CARDS for enabling support for various graphics cards in packages. Setting VIDEO_CARDS to trident will pull in the correct driver:
After setting this you want to update your system so the changes take effect:
You can force X11 to use desired driver with:
If you have the USE flag acl enabled globally and are using ConsoleKit (i.e you're using a Desktop profile) permissions to video cards will be handled automatically. You can check the permissions using getfacl:
A broader solution is to add the user you want to be able to access the video card to the video group:
Note that you will still be able to run X without permission to the DRI subsystem, but usually not with acceleration enabled.