For rpm, deb, and arch linux, if one includes video=hyperv_fb:hhhhxvvvv (where hhhh is horizontal pixels, vvvv is vertical pixels),
then when booting, the hyperv window resizes itself to hhhh x vvvv.
This setting is entered on the GRUB_CMDLINE_LINUX line in grub.cfg.
It is very useful, because one does not have to resort to vnc or rdp to get similar results.
However, I have been unsuccessful determining how, where to set this in FreeBSD, GhostBSD, or PC-BSD.
Can anyone point to a solution?