Installation fails on HP T610 Plus Thin Client internal flash (EFI)

I've just rebooted the system and it dropped into a GRUB prompt.

I managed to boot it manually using the instructions here: https://askubuntu.com/questions/38082/how-do-i-manually-boot-from-the-grub-prompt-after-do-release-upgrade

After booting into Xubuntu, I ran:

<pre>sudo grub-install</pre>

Which ran to completion and appears to have succeeded ("Installation finished. No error reported.")

I've just found out that the "shim-signed" package hasn't installed, so I'm waiting for <pre>apt-get install -f</pre> to finish.

Shim-signed failed to install. Here's the terminal output:

root@cedric:~$ sudo apt install -f
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up shim-signed (1.34.9.2+13-0ubuntu2) ...
Installing for x86_64-efi platform.
Could not delete variable: Invalid argument
grub-install: error: efibootmgr failed to register the boot entry: Block device required.
dpkg: error processing package shim-signed (--configure):
 installed shim-signed package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 shim-signed
E: Sub-process /usr/bin/dpkg returned an error code (1)

Can you attach the output of the 'dmesg' command when this happens? This really shouldn't happen at all, but maybe we can get some more verbose information from the kernel about what's failing.

Also, if grub-install succeeded for you once following a reboot, it seems that it's not *impossible* for Ubuntu to write to the nvram... but it definitely isn't working consistently.

Hi Steve, thanks for the response.

I managed to get this working by coldbooting the machine, then ran:

   sudo update-grub # this fixes the missing GRUB config

Next I installed Vim -- APT figured out that shim-signed hadn't been configured, and retried. This time it succeeded!

The machine came with Windows 7 Embedded, and I warm-booted into the installer (reboot from Windows, select "boot from USB stick" in the BIOS boot menu). I suspect the warm-booting may be a factor.

Regardless, I will probably be doing a reinstall on this machine anyway and will update the ticket if I find out anything further.

Ok, with a compliant EFI implementation, there's no reason that warm vs cold boot should be a factor either, but it's interesting to know and gives us a starting point.

If you've hit the problem so many times already, it seems likely that the problem will reproducible again on updates to the grub2-signed or shim-signed packages on your system. You may even be able to reproduce it manually by running 'efibootmgr' commands. Any reproducer that gets us some dmesg output would be helpful.

Status changed to 'Confirmed' because the bug affects multiple users.