Did qubes-dom0-upgrade to R4.0, won't boot

[Demi Obenour]

I upgraded my install to R4.0 and now my system won't boot.  How can I fix it?

Some notes:

- Firmware recognizes Qubes, tries to load it

- Qubes won't boot

- The filesystems CAN mount when I do a rescue boot.

- Transient message is attached

[Yuraeitha]

I did not watch the video you attached, can you perhaps instead describe what happens? For example, does your screen go black during boot after install? or during early install? Such details may provide vital clues.

It sounds a lot to me like it's a graphic driver issue, which is probably due to the kernel, or associated modules. Everything written below, follows that "assumption".

- For Grub, you can easily temporarily modify the grub settings during early boot, by pressing the E key on a grub menu. Put "nomodeset" somewhere in the latter part of the Module line.

- For EFI, you'll have to either fetch a live-boot to gain access to Qubes root system, and then edit the efi.cfg file found somewhere in /boot, typically /boot/efi/EFI/qubes/xen.cfg or something like it, or if you're terminal savy, you can edit the file directly from the qubes dom0 terminal that you reported you gained access to (probably the most easy if you're that far already). This fix applies both to the EFI installer medium, as well as any finished installed system booting via EFI, whichever is having the black screen.

- Grub is by far the most quick to troubleshoot, but they may also act differently, for example on which drivers they load. Try both approaches, see if one works.

- You can also try disable IOMMU for GTX graphics. If you know your system fully meet the system requirements, then try change UEFI settings. Sometimes it's a rogue setting messing everything up, sometimes it may be a really unlikely setting. For example I've once seen Qubes unable to boot up, because external graphic card was sharing memory with the internal graphic card. Stuff like this, trial and error and see if you can find something.