Ubuntu image failing to boot after mender-convert + potential solution?

Board Integrations Debian family
1

Hello, mender devs!

I’ve been using mender on several NUC8BEK SBCs without an issue. Recently, however, I cloned the same golden image that I’ve been using for all of the previous NUC8BEKs and noticed that after boot, it went directly to the GRUB 2.04 shell. I tried mender-convert on several nuc11s and my laptop and the same thing happened.

I noticed that a split second before dropping the shell, it flashed the following “error: no such device: {uuid-of-device-that-doesn’t-exist}”

I then tried to manually get it to boot by runing “set prefix=/efi/boot” followed by “configfile /efi/boot/grub.cfg”

It then, returned an error about being unable to find the ‘hashsum’ command twice, followed by “environment 2 still corrupt after attempted restore. Halting”

It was then that I realized that the wrong grub.efi must be getting called. I noticed that after mender-convert, there is still an /ubuntu entry under /efi that is supposed to not be called anymore, because of the /BOOT entry that contains the mender version of grubx64.efi.

I then removed all references to hashsum in the grub.cfg and was able to get it to boot by running the set prefix and configfile commands.

After doing some more digging, I realized that the grub efi inside of /ubuntu was being called instead of the efi inside /boot.

After yet more digging, I realized the reason was that the bios was looking for the BOOTX64.CSV that’s contained in /ubuntu. So, I added my own BOOTX64.CSV inside of /boot that pointed to mender’s BOOTX64.EFI, and suddenly it booted without any issues.

Is this a potential solution, or is this just a fallback band-aid over some other issue?

2

This sounds reasonable to me. Each hardware and OS combination can have its own quirks requiring changes like these. The best way to handle this would be to implement a custom hook in your mender-convert config files.

Drew

3

Thanks, Drew. It seems like this is really common across a lot of x64 efi installs (at least two different nuc models and a laptop and desktop that I tested on so far). I’m happy to add it as a hook, but it might not be a bad idea to also add it to the generic x86 config file in the official mender-convert repo, given that it won’t affect bios firmware that isn’t looking for a Bootx64.csv.

4

Yeah, if the code is generic then we will certainly be happy to pull it back into the main repo. I guess the question is how do we determine on which machine/OS combinations it would be needed? I think if you prototype it as a hardcoded hook in your case then we can review it and hopefully together we can figure out when it should be applied.

Drew

5

I’ve run into the exact same issue, took me days to track it down; thanks for your post.

Do you have any configs floating around which can help me automate this? I’m not the best at programming!

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