PC Engines APU3D4 firmware?

Hiii, so do any yall know where we can get our hands on some UEFI-based coreboot images for the APU3D4? Apparently there are ones you can pay for but um..... fuck that? We're not paying for firmware updates for some dinky little AMD-based SBC, you're not Sun. At the second, we're having rather a lot of trouble getting Coreboot + Openboot to build, so UEFI is the next best option. Uh... halp?