coreboot

I use the w530 (with Debian 12 + edk2), but this may also be happening with other thinkpads.

When I connect to external displays and turn on, while the graphical environment shows as normal, the tty or anything not graphical doesn't show. This includes anything prior to the graphical display manager (such as lightdm). For example, when LUKS asks for the password for my encrypted drive. (The GRUB screen also doesn't show, but I can't recall if this was already the case with the stock bios. It also never showed with SeaBIOS, so maybe so).

With SeaBIOS, the tty etc. does show, but only with nouveau open-source graphics drivers. The nouveau driver suffers from screen tearing on this system, so I switched to proprietary nvidia drivers (Tesla 470 for w530) to resolve this. While it did cure screen tearing, I got the same problem as with edk2.