12.0-RELEASE kernel hangs on Dell Precision 7920

[Alexey Dokuchaev]

Hi there,

I've installed FreeBSD/amd64 12.0-RELEASE on this beefy Dell Precision
7920 Tower workstation, but it does not boot unless I disable "Memory
Map IO above 4GB" option in BIOS (UEFI): the kernel hangs right after
"ACPI APIC Table: <DELL\x CBX3   >" line.

Interestingly, it also won't boot if I disable NUMA (Non-Uniform Memory
Access).  This is for vanilla GENERIC kernel.  Is this something known?
Any ideas?  I'd happily test patches, etc.

./danfe

P.S. Ubuntu 16.04 LTS boots just fine on this box with default settings.