This is one of three patches adding support for non-native panel orientation.
The other two patches add similar support to the drm module, and to the vt framebuffer.
Each of these patches may be applied separately or not, but consistent
rotation through all phases of bootstrapping and running the system console
will require all three.
The screen orientation is set by adding
to /boot/loader.conf. This value is passed by the loader to the kernel for use after
bootstrapping, but the loader needs the information before /boot/loader.conf is
To solve this problem, during startup and shutdown the loader.conf file is read and
the appropriate rotation angle is stored in a UEFI variable by /etc/rc.d/uefivars.