Well, I did
and it worked. The driver is now installed. Then, I added "linux_enabled=yes" to rc.conf, but when I startup GDM, the native resolution is something around 640x480.
I do want to play a lot, so I don't want to drop linux support...
EDIT: I thought, maybe the driver IS installed, maybe the default resolution is not set; I tried
and when I want to start gdm now, I get following error:
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmDisplay: display lasted 0.somewhat seconds
gdm-binary[1145]: WARNING: GdmLocalDisplayFactory: maximum number of X display failures reached: check X server log for errors