How to edit GRUB options, unable to boot

[apparatus]

@pronubio

I have a laptop with HDMI, this HDMI works even without Nvidia, I don’t have any other option to attach any other display.

Are you sure that HDMI is directly connected to Nvidia and not through Intel?
[GUIDE] Optimus laptop dGPU passthrough · GitHub
[GUIDE] Optimus laptop dGPU passthrough · GitHub
Check your BIOS settings, maybe there is some option to connect Nvidia to HDMI directly:

For some Dell laptop (such as mine), There is a Display port direct output mode option in Video → Switchable Graphics, enable it and it will assign all display port (mDP, HDMI, Thunder Bolt etc.) directly to the dGPU. Check if your BIOS offer some similar options.

If there is no way to use Intel GPU for your laptop display and Nvidia GPU for HDMI then you can try this:

Seamless GPU passthrough on Qubes OS with VirtualGL

We are presenting to you a guide regarding GPU passthrough created in collaboration with peers. Qubes OS already has extensive documentation available about GPU passthrough for 3D accelerated tasks but they all require in depth configuration, extra displays, and extra input devices. With VirtualGL (https://virtualgl.org) one can take advantage of the existing Qubes OS framework for audio/display by offloading OpenGL onto the secondary graphics card directly with VirtualGL. This document will mo…

[pronubio]

I shouldn’t even suppose to get Nvidia working with external display if the display connected through Intel-Nvidia HDMI?
I most definitely have the MUXless laptop.

Just for the sake of it, tried to install manjaro without Qubes and it picked the right drivers, but when I tried it with Qubes, no matter what I did, it just didn’t work.
Maybe I did miss something.

Prob gonna give up on GPU passthrough, it ate 3 days out of me already.

Thanks apparatus for trying to help out.

[apparatus]

@pronubio

I shouldn’t even suppose to get Nvidia working with external display if the display connected through Intel-Nvidia HDMI?

I think so. At least not directly.
If you have your external display working in dom0 with iGPU then you can just passthrough Nvidia GPU to some qube and use VirtualGL inside this qube. Then you can move this qube window to your external display in dom0 and make it fullscreen.

@pronubio

Just for the sake of it, tried to install manjaro without Qubes and it picked the right drivers, but when I tried it with Qubes, no matter what I did, it just didn’t work.

You didn’t passthrough your Nvidia in manjaro. It’d work the same in dom0.
You can try to passthrough your GPU in KVM in manjaro and try to use HDMI - then it’d be comparable.