From the FreeBSD Foundation’s December 2015 (end-of-year) update, in summarizing their development efforts, they mention firmware (as well as improvements to x86 hardware support, and AArch64 support):
UEFI and secure boot: FreeBSD’s UEFI boot support needs to interoperate with many different EFI firmware implementations, and it’s only after broad testing that we were able to identify some incompatibilities. Through effort from Foundation staff and from volunteers in the FreeBSD community we’ve fixed UEFI boot on a variety of hardware and virtualization platforms, including Apple Macbook and Mac Pro computers and VirtualBox and VMware. These improvements will be available in FreeBSD 11.0 and 10.3. We also started working on support for secure boot. To date we’ve been working on individual tools — the uefisign(8) utility to add Authenticode signatures to EFI files, and the sysutils/pesign, sysutils/sbsigntool and sysutils/shim ports. Next year we’ll integrate these components into a broader secure boot implementation.
More information: click on the tiny-URL PDF in the below tweet:
Firmware Security 