I have updated the bios of the T480s yesterday and loaded the default settings of the bios. In the process I lost the QubesOS entry for booting.
I was able to restore the entry by booting with:
Super Grub2 Disk Live-Iso in QubesOS
and with this command in Dom0:
efibootmgr -v -c -u -L QubesOS -l /EFI/qubes/grubx64.efi -d /dev/nvme0n1 -p1
Now I get this error message when booting:
Welcome to GRUB! error: file '/EFI/qubes/fonts/unicode.pf2' not found.
How can I fix this?