I have a "test all the operating systems"-laptop which was running Windows and Ubuntu MATE, with rEFInd used as boot manager.
Unfortunately I can no longer boot the old OS:es. Neither rEFInd. After some reading I guess Qubes is legacy-boot only, but why that has completely broken my UEFI-booting the old systems I do not know.
Qubes installation of grub boots fine, but if I try to launch rEFInd from it it fails:
grub> ls (hd0) (hd0, gpt10) (hd0, gpt9) (hd0, gpt8) (hd0, gpt7) (hd0, gpt6) (hd0, gpt5) (hd0, gpt4) (hd0, gpt3) (hd0, gpt2) (hd0, gpt1) grub> chainloader (hd0,gpt3)/efi/Boot/bootx64.efi error: invalid signature
Manually trying to select the efi-files from the computers firmware fails, the mouse even hangs when the firmware tries to list available efi-files from the hard drive.
Booting rEFInd installed on a thumb drive works fine, so I conclude the firmware on the machine is intact, but the hard drive got messed up by the Qubes installer.
What did it do to my drive? How can I restore it?