Tried to perform an update from 20.04 LTS to 20.10. All was going well until the final reboot “into” 20.10, and my computer fails to get to the desktop when booting normally. It flashes between a purple screen and a black screen and never loads the gnome desktop. It then seems to basically hang.
Naturally I then tried recovery mode from grub, and weirdly, everything boots when I go in via this route, choosing “resume”. However there’s still some graphical anomalies during boot, (dialogue box appears with a basic theme on the UEFI background, and then disappears), and I noticed that in – Settings – About, it’s listing llvmpipe as the graphics, rather than the Intel iGPU when I go in this route. Weirdly, it also offers to (and defaults to) boot using the 126.96.36.199 kernel (which I didn’t manually install) above the listing for 188.8.131.52 (which is what I believe 20.10 ships with.
My box is an HP ex-chromebox (Haswell Celeron 2995U. 1.4GHz) which ubuntu has breathed new life into even if it’s a rather weak machine. Thought I’d get used to Ubuntu on something I already had first even if it is weak! Ubuntu opens up so much more than it could originally do so I’d like to get it back, especially as it was really impressive so far.
I have used a discrete GPU on this box though an rather hacky EGPU connected to the WiFi pci-express port (an Nvidia GTX 960) but I usually use the iGPU unless it needs the extra oomph for something – what I think happened during the update, is that the update disabled the proprietary Nvidia drivers and the Nvidia dGPU/iGPU switching, and this has messed up the X.org server settings meaning it doesn’t know what to do for graphics when it boots. Recovery works by switching to the lowest form of compatible graphics modes. Yes I wish I had not made life hard for myself.
I thought purging the Nvidia drivers would fix it, but now I’ve far enough down this rabbit hole that I’m lost. I started trying sudo X -configure and get an error:
FATAL: Module fbcon not found in directory
I don’t know enough about X.org.conf to have a clue what to edit in there.
I then thought I’d try a repair install from an Ubuntu live-USB, and run into a mount point error. At this point I’m ready to give up, but I’d really rather not have to start over. I figure the other thing worth trying is to reinstall the nvidia drivers and see if I can undo what I’ve done that way, but I thought I should ask before I cause any more damage!
I do thankfully have a backup of my home directory if I have to resort to that, but any better ideas as to how I can reset this mess without basically wiping and starting again?