kernel trap 12 with interrupts disabled

[Chris H]

OK. This is my second world/kernel on 12.
The last, ~3 mos. ago, worked great. But, unfortunately,
the graphics on the APU (AMD/ATI A6 7470K)  aren't
(yet) supported on FreeBSD. So I picked up an nVidia
Geforce GT 730, and performed a fresh install from the
r314495 AMD Disk1 CD. Then checked out a fresh copy
of src && ports, last night (PST) to begin a fresh
buildworld/kernel installworld/kernel. I finished the
buildworld, and finished the build/install kernel, and
(attempted) to boot to single user. But got a trap
shortly into booting the new kernel;

kernel trap 12 with interrupts disabled

Fatal trap 12: page fault in kernel mode

I've placed a screen shot here:
bsdforge.com/12-CURRENT-2017-03-04.jpeg

for better context, and what follows what I've mentioned
above.
I've left it at this point with the db> prompt. In case
I/we can better determine what cause it.

Please advise.

Thanks!

--Chris