Multiboot Qubes with GRUB on a different drive

I have a unique use case, I mainly produce music with Windows, use Qubes for school and development, and Gentoo for everything else. This facilitates the need for a tri-boot setup, with GRUB installed on a separate Gentoo SSD which has an entry for windows. The issue is that I have not found any documentation regarding adding an entry to successfully boot Qubes from GRUB on my Gentoo install. Could anyone point me in the right direction?

I should note that I am on Qubes 4.1.0 with a strictly UEFI bios configuration (no csm).

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probably I’ve misunderstanded, but… have You tried to check your bios boot manager and see if UEFI entry of qubes-os isn’t there?

Yes it does show up, but that is what i’m trying to avoid. Entering the BIOS boot menu is really inconvenient and makes a super loud beep. I would like to boot qubes through my gentoo install, and the grub that sits on the /boot partition of that drive, if that makes sense

In this case, have You tried something as:

menuentry "Boot from second disk" {
   chainloader (hd1)+1

or: GRUB - ArchWiki


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Yep i’ve using tried that and os-prober, and both try to launch dom0 without xen or something along those lines. It also has to load with special .efi files found in /boot. I’m not sure how to configure this without wrecking my other boot entries. I’ll do some testing when I get home later and see what works and what doesn’t.

Did you install Qubes with a boot partition? If so, could you try this:

When GRUB loads you normal menu, press ‘c’ and type:

configfile (hdX,gptY)/efi/qubes/grub.cfg

? - If you don’t know X and Y, you should be able to press tab and get a list of known partitions – look for “Filesystem type fat”. If this works, I think you can do something like:

I’ve not tested it, but looks like you should be able to add something like:

menuentry "Give me QUBES" {
   insmod xfs
   search --set=root --label OS1 --hint hdX,gptY
   configfile /efi/qubes/grub.cfg

to your normal GRUB configuration.


Thank you so much! that did it. I just had to copy /efi/qubes over to the other /efi folder and add your custom entry. It’s definitely not pretty, since it loads grub again before booting, but functionality is perfect and I still have access to all of the recovery options.