

GRUB loads before any kernel driven hardware module, so this machine is just working on the native orientation of the CMOS and Display at that point.
https://wiki.gentoo.org/wiki/Tallscreen_Monitor
Seems to suggest that the fbcon argument should work, but which version of Grub you’re using matters. Make sure you update initd if using Grub2.























Which file did you edit for these Grub changes?