Can't get Mac Mini to boot with NetBSD 8.2

Friends,

I am trying to upgrade my machine from NetBSD 7.2 to NetBSD 8.2 on a slightly newer Mac Mini (Intel).

The USB stick boots ,and the install is almost flawless, but I can’t get the mini to boot NetBSD.

Is there any documentation out there on how to make this go?

I finally installed rEFInd on the machine, which works great, but I’m having trouble with how to refer to the partitions and second-stage bootloader on the rEFInd side versus the NetBSD command line environment versus the installer’s environment. Again, I can install and boot Mac OS X, but not NetBSD. I think the problem is that I don’t know how to refer to the “DK” partitions versus the “wdx” device terminology of NetBSD to link rEFInd to NetBSD.

Again, is there documentation out there on how to do this?

I have found docs on installing and partitioning disks for old machines, even MacPPC Minis, but not for the “relatively” new EFI firmware.

Help?

THanks much,

-dgl-