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Ubuntu adds ubuntu to the UEFI boot list (it can be queried with efibootmgr). Does this only happen during initial setup of Ubuntu or does this also happen during some other time?

If so, how can I disable it, so that Ubuntu doesn't bother managing this entry (that is creating/updating it)?

I am asking this question for Ubuntu 18.04 and 20.04.

0xC0000022L
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  • u mean the option in UEFI BIOS Boot Menu not in grub?? – PRATAP Jun 22 '20 at 10:41
  • @PRATAP correct. Perhaps tagging it grub2 was sort of ambiguous there. I went by the assumption that the two have something to do with each other. Let me remove that tag and replace it by something more sensible. What I am talking about is the aspect that can be queried and set via efibootmgr. – 0xC0000022L Jun 22 '20 at 12:35
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    To the best of my knowledge, that entry is only added during system installation. After that Ubuntu essentially uses GRUB to manage individual entries for the various kernel versions installed. See, e.g., https://askubuntu.com/a/1185257/158442 where someone wrote a whole tool for renaming entries, but doesn't mention having to rename again and again. – muru Jun 22 '20 at 12:48

1 Answers1

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I know of at least 3 where you can add boot options to EFI.

  • During installation. This one is unavoidable.
  • When doing apt-get install --reinstall grub-efi.
  • When using efibootmgr.

The last 2 are up to the user of the system so not executed by Ubuntu.

  • grub-install does it too if you omit --no-nvram.

    --no-nvram
Don't update the `boot-device'/`Boot*' NVRAM variables. 
This option is only available on EFI and IEEE1275 targets.

NVRAM is non-volatile RAM that is used in EFI to store variables that need to persist between boots. Many of these NVRAM variables are architecturally defined, and setting invalid options to NVRAM could cause a machine to not be able to boot.

Rinzwind
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  • Excellent. That information helps. Should I uncover another "source" for this entry, I'll attempt to track it down and update your answer or write my own. Thanks. – 0xC0000022L Jun 22 '20 at 13:15
  • Oh and you could always add in a "efibootmgr delete" for "ubuntu" during startup if you want to get rid of it – Rinzwind Jun 22 '20 at 13:44
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    The grub-install-command is worth mentioning, at least it has a --no-nvram-option. – mook765 Jun 22 '20 at 13:47
  • @mook765 thanks :) added bit about the option and nvram itself – Rinzwind Jun 22 '20 at 17:26