uefi

Some instructions can be found at FreeBSD wiki and FreeBSD forums

If X doesn't start with message similar to "Cannot run in framebuffer mode. Please specify busIDs" and you are booting your system using UEFI you should install package drm-kmod, and make sure to load appropriate module before starting X (for example i915kms.ko), but beware that after installing package modules with same names will be present in both /boot/kernel and /boot/modules, so it is necessary to give full path to module to load (for example kldload /boot/modules/i915kms.ko).

If you have to set native resolution on system console (if for example you have to run scfb driver for X), first check resolutions supported by UEFI - escape to loader prompt when booting OS and type:
mode
That should list all textual modes recognized by loader (alternatively you can also try gop list or uga list, but saving gop mode setting using following method won't work (I don't know about uga since my computer doesn't support it)). After this you can set mode you want to use using
mode NUMBER