DragonFly lead developer Matthew Dillon has landed EFI runtime ABI support that was ported over from the FreeBSD code-base.
This EFI runtime ABI support allows for querying and setting the time, scanning EFI BIOS variables, and more. This code was ported from FreeBSD but with various changes for DragonFlyBSD's different kernel interfaces.
More details via this commit. Dillon also explained via the mailing list that the feature is still very much experimental for now, "it is possible to permanently brick your machine (as one of our developers found out the hard way) if you play
with it. So even though this code is now present, we do not recommend that anyone use it unless they are willing to lose their motherboard (!). The module is not loaded by default."