port-amd64/59781: Thinkpad T450s Kernel panic on first boot on amd64 11-BETA

[milewi%utu.fi@localhost]

>Number:         59781
>Category:       port-amd64
>Synopsis:       Thinkpad T450s Kernel panic on first boot on amd64 11-BETA
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Nov 21 12:15:00 +0000 2025
>Originator:     Michael
>Release:        11-BETA
>Organization:
University
>Environment:
Not possible to obtain due to panic at boot.
>Description:
Hello,

I have done a problem query request via https://www.netbsd.org/support/query-pr.html using Thinkpad T450s as the keyword, to establish that there are no existing reports dealing with the T450s.

The described system has the following speficiations:

Thinkpad T450s
BIOS version JBET73WW (1.37)
BIOS release date 08/14/2019

This pr concerns a fresh NetBSD 11-BETA amd64 install from a dd?d 8gb flash disk and an unmodified kernel.

Booting from the flash disk and a GPT-based partition scheme (whole disk) went fine. Upon rebooting the following (a video) presents a panic followed by a stack trace.

Prior attempts using amd64 9.4 on the same hardware, installed and booted as expected into a usable state. Prior attempts with amd64 10.1 on the same hardware, also resulted in a similar failure to boot issue. 
>How-To-Repeat:
Complete a standard GPT install (with all sets and a GUI) of 11-BETA on a Thinkpad and reboot the system.

I have a video of the sequence and all output from boot (157mb), that I would be happy to send if someone is available to receive it.
>Fix: