HP Revove UEFI boot

[WolfPit]

I have installed Kubuntu 21.10 on an HP Elitebook Revolve G3. The settings in the BIOS are UEFI, no secure boot. After installation from USB, the OS is not found. The BIOS resets the system claiming that no hard drive is installed. When calling up BIOS and reviewing Boot options, an entry 'ubuntu' appears. Selecting this entry boots into Kubuntu without problems. Running efibootmgr gives tghe following output;:
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000
Boot0000* ubuntu

Obviously, there is something wrong with the way Kubuntu implemented booting: The system BIOS does not find an entry booting Kubuntu. Note that on the same PC with the same settings I had previously installed Zorin OS 16 WITHOUT ANY PROBLEMS.

It appears that something in the boot options of Kubuntu must be fixed but I have no idea where to start.
Appreciate any suggestions

[jlittle]

Ah, buggy UEFI implementations. If it can find an "ubuntu" entry in the settings, why can't it at first?

I'm curious about sudo efibootmgr -v would say. It should be something like:

Boot0000* ubuntu        HD(1,GPT,xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx,0x800,0x100000)/File(\EFI\UBUNTU\GRUBX64.EFI)

Anyway, rerunning grub-install should fix it. Ensure that the ESP is mounted at /boot/efi, and it should just work.

Conceivably, the Zorin OS created an ESP and the Kubuntu install did not trample on it.

[WolfPit]

Thanks much. You are probably right with the previous Zorin installation co-creating the problem. Here is the output:ootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000
Boot0000* ubuntu HD(2,GPT,88a43066-885e-4490-b779-6157a0b74d40,0x1000
,0x100800)/File(\EFI\ubuntu\shimx64.efi)

[WolfPit]

Re-running grub-install: from within the installed Kubuntu? With ESP you mean the hard drive? How do I check for the correct mounting? Many thanks again.

[WolfPit]

I reviewed my partitions and found: /dev/sda1 grub2-core.img, and /dev/sda2 EFI system partition. Both are mounted. I am not sure to which partition Grub-install would have to point. Thanks again.

[jlittle]

My suspicion of legacy install influence is supported by the presence of grub2-core.img. My UEFI installs don't have it.

... Neon EFI ...

An EFI belongs to a computer, not an OS. There should only be one, used by all the OS's on the computer. If your intention was to install only Kubuntu on the HP, I suggest wiping the storage device by writing a new GPT partition table.

...I am not sure to which partition Grub-install would have to point...

With Grub2, you normally run grub-install on a device, f.ex. /dev/sda, not a partition.

You might not want to bother with this level, but I usually use a live session ("Try Kubuntu") to partition the storage they way you want before running the installer. Then in the installer, choose "Manual" and then tell the installer which partitions to use. For a vanilla install there'd only be an ESP, and the rest one big btrfs.

[WolfPit]

OK so it seems the best option is to completely wipe the SSD with e.g. gparted, then reinstall. IN the HP BIOS there are three options: legacy, UEFI-CSM and UEFI. Somewhere I saw that for HP Elitebooks it was suggested to NOT use UEFI-CSM, only UEFI. But Zorin did not bother. Based on your experience, do you suggest UEFI, or might UEfI-CSM also work? Thanks agaon for this help.

[jlittle]

...it was suggested to NOT use UEFI-CSM...

I agree, a straight UEFI set up should be used if possible. UEFI-CSM is some weird compatibility mode. Just make sure you boot the installer in UEFI mode; how exactly to do that depends on the machine.