I recently performed an in-place upgrade of my 11.2 system to 12.0, and upon reboot the machine freezes at the BTX loader screen after twirling the little loading cursor for a few seconds. I get the same result with a fresh download of version 12 booting off a USB stick as well.
I've tried booting a USB of 11.2 (works!) and also disabling the WHEA ACPI feature in the BIOS (as reported by another user who reported that that setting was a workaround for a 10.0 BTX issue).
My hardware is a Supermicro H8DGi-F motherboard with two Opteron 6300s, 64GB of RAM, Intel i350-T4, and a Broadcom SAS 9207-8i HBA. It's been working wonderfully on FreeBSD 11.1 and 11.2 for a while now.
Anyone have a suggestion on what to do?
It could matter what boot fileystem you use, how your boot disk(s) are partitioned, etc.
(In reply to Andriy Gapon from comment #1)
I'm not quite sure what you mean. The boot filesystem is the live USB, and (correct me if I'm wrong) but I don't suspect that my physical disks are read from or even seen at this point in the boot process if off a USB stick.
I will unplug the HBA and see if that makes a difference. I have no disks hooked up to any of the SATA ports on the motherboard, so this should be easy to test.
Cross reference https://redd.it/aod9py
The unified ufs / zfs loader probes all the drives.
Details and a patch are in PR 236585.
If the patch doesn't help, then what you can do is add print statements
to find out where the loader is going splat. The PR I mentioned lists
some of the routines of interest. To debug I built the loader, copied
to /boot/loader.new, and then during boot manually choose loader.new
(this way the system would still boot normally while chasing down the
issue with the newer loader).