I had to install Qubes in legacy boot mode because in UEFI boot mode (the default on my new PC), the Qubes installer just showed a blank screen. I was unable to switch to legacy boot mode without purchasing and installing a graphics card, because the Intel built-in graphics refuses to boot in legacy mode. But after installation I experienced two problems:
After some time, the machine would drastically slow down. I suspect this is because the intel_pstate driver should be used but Qubes does not support this, at least not out of the box.
After using it for a few days, I suddenly experienced rapid flickering and blanking of the middle 2/3rds of the display.
To try to solve both of these problems, I decided to remove my graphics card. However, the BIOS detected this and, because the Intel graphics doesn’t support legacy boot, it reset back into UEFI boot. So now the machine is booting straight back into Windows 11.
How can I boot back into Qubes, and how can I set it up for EFI boot?
I tried using the Rescue option on the installation USB, but just like the installer, that just gave me a blank screen after the boot menu.
From some Googling it seems like it may or may not be possible to boot into Qubes using kexec from a Linux live USB stick. But I don’t know how to do that. Can anyone give me any pointers?