> duplicated the procedure, it didn't work.  There's more to it than just
> enabling xdm in /etc/rc.conf.  It also involves changing /etc/ttys and
> making sure the X server binds to the right tty.  And then there's the
> files in /usr/X11R6/lib/X11/xdm/.   The Xservers, Xsession, and
> xdm-config are files that you may want to configure.  Xservers sets the
> tty and it also sets other aspects of the server.  By default, the X
> server boots up in 8 bit color.  You have to add a -bpp=32 to get true

or edit XF86Config adding DefaultColorDepth 32