Recently, there’s been (actually two) ports of TianoCore (the reference implementation of UEFI firmware) to run on POWER on top of OPAL (provided by skiboot) – and it can be run in the Qemu PowerNV model.

More details:

• http://firmwaresecurity.com/2015/10/12/tianocore-for-openpower/
• https://github.com/andreiw/ppc64le-edk2
• https://github.com/ozbenh/edk2