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I have run Boot Repair on my machine and then rebooted my machine with my Live USB out.

From this point, I was first presented with a screen that said

1) "Shim UEFI Key Management" then was presented with

2) Boot Manager screen with two options: a) Unknown Device and b) Windows Boot Manager. Selected "Unknown Device" as option (b) did nothing.

3) After this, saw a GRUB ver 2.02 screen with the first option of *Ubuntu, which then eventually got me into Ubuntu.

The above sequence of steps occurs everytime I reboot my machine.

Why all these steps?

FYI, here is my boot-repair info: http://paste.ubuntu.com/10562192/

You will notice that on lines: 549, 741 and 776, I am getting the line:

Boot0000* Unknown Device:   HD(1,800,100000,aa8f4a18-e5fc-41ff-bb2d-826eab7312c9)File(EFIubuntushimx64.efi)RC

Would this be the reason I am getting the "Unknown Device" in my Boot Manager?

Thanks.

tonyf
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1 Answers1

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The "Shim UEFI Key Management" screen is probably MokManager, which manages Secure Boot keys used by the Shim program. Shim is a signed pre-GRUB boot loader whose job is to enable Linux to boot on a computer that uses Secure Boot. Secure Boot is a complex topic; see my page on the subject (or many other pages; Google to find a selection) for more details.

The fact that you're seeing the same MokManager screen pop up on every boot means that either you're not registering a key or your firmware is forgetting them. If you're able to get into Ubuntu without registering a key, then my suspicion is that you've got at least two Linux boot paths registered; one is failing and then the other is launching. If you do register a key, then as I said, your firmware is forgetting them.

Posting your Boot Repair pastebin file would be helpful, yes.

Rod Smith
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  • FYI, added Boot Repair pastebin file link in my thread above with some additional info. – tonyf Mar 08 '15 at 15:18
  • With Secure Boot - do I need to disable it within my BIOS? – tonyf Mar 08 '15 at 15:26
  • The names shown in efibootmgr may show up in your firmware's boot manager, so that is probably the source of "Unknown Device" there. It looks like you've got at least two (I suspect three) copies of Shim, and at least one of them isn't working, hence the failure and fallback to one working entry. Please review the Secure Boot link I posted earlier, and the first two sub-pages on its parent page. This will give you the background you need to track down which Shim copy is causing your problems and delete it. – Rod Smith Mar 08 '15 at 15:28
  • Where exactly (filename), do I delete these Shim copies and secondly, do I need to do anything with this "Unknown Device" issue? Thanks. – tonyf Mar 08 '15 at 15:31
  • Don't get hung up on the name "Unknown Device;" that's intended to be descriptive text for human consumption -- although some tool obviously botched that intention. As to where the files are, in Linux, they'd probably be in /boot/efi/EFI/ubuntu and /boot/efi/EFI/BOOT, although the suspected third copy will be elsewhere, perhaps not even mounted. That's why I said to read those pages; they'll describe what you need to know to figure out where things are. What little standardization there is on this is insufficient for me to give you specific instructions. – Rod Smith Mar 08 '15 at 20:53
  • Please see my answer which should also apply to single-boot. Acer Aspire series has an extra step. https://askubuntu.com/questions/1062418/cant-boot-into-live-usb-though-secure-boot-has-been-disabled/1062530#1062530 – Raffles Jul 19 '20 at 12:42