Bug#1062073: Re: Bug#1062073: grub-efi-amd64: GRUB 2.12 fails to boot with X64 exception

[Morten Hein Tiljeset]

So I spent an evening bisecting the issue from upstream sources.

The problem was introduced with
> 7b192ec4c term/ns8250: Use ACPI SPCR table when available to configure serial

The old behaviour can be regained by setting the unit explicitly grub.cfg
> serial --unit=0 --speed=115200

This solves my issue, so you can go ahead and close the bug report.
I assume the ACPI lookup logic triggered a bug in my particular firmware.

/Morten