Recovery functions blocked by firmware password after installing rEFInd boot loader and Ubuntu partition

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Level 1

18 points

Recovery functions blocked by firmware password after installing rEFInd boot loader and Ubuntu partition

Ok, long story: Used dual boot with OS X Mojave and Ubuntu 18.04 on separate partition (iMac Retina 5K, 27-inch, Late 2014). Everything was bliss until an Ubuntu bug started locking me out of my personal folders and everything went into a "snap" folder on the desktop. Disaster struck after I tried to repair Ubuntu and resulted in a totally wrecked Ubuntu OS. rEFInd boot loader disappeared and the dreaded Grub loader hijacked the computer booting into a destroyed Ubuntu OS each and every time. With the aid of my wife's computer I managed to create a bootable USB stick with Mojave and managed to start and recover my Mac from there using time machine backup. The McIntosh HD now back to its former 3TB and everything should be hunky dory, but with a looming shadow and worry:

I cannot reach recovery by restart and hold cmd-r without getting a firmware prompt. Same with internet recovery opt-cmd-r. Holding "shift" with the intention to get to the boot loader menu does not work and firmware prompt appears.

Re-starting the computer holding "space" will not get me into safe mode and opt-cmd-r-p will just start the computer without re-setting the PRAM.

Also, the computer use a much longer time booting than before even if it is just as fast when once booted.

Prior to my (stupid) experiment with dual boot and Ubuntu my mac was never set with a firmware password and never had such problems, leading me to a nagging suspicion that it has been compromised or been hacked during my endeavours.

Maybe somebody in this community has a solution/fix that can put my Mac straight and mind at ease?

Please ask questions in case there is a need for clarification on any matter regarding this.

iMac with Retina 5K display, macOS 10.14

Posted on Apr 20, 2019 2:23 AM

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Answer 1

HWTech

Level 9

55,664 points

Apr 20, 2019 9:30 PM in response to Halonk

I've seen some Apple systems spontaneously have the EFI firmware lock enabled without any user intervention and running only macOS. You will need to provide proof of purchase to Apple so they can unlock it for you. See the instructions at the bottom of the page here.

FYI, as for GRUB booting directly into a broken Ubuntu, you could have either pressed the "Esc" or "Shift" key (I forget which one it is) to have GRUB display the boot menu so you could choose the macOS boot entry which is likely normally hidden by a splash screen. Or you could have performed an Option Boot to choose the macOS boot volume. A third option would have been to perform a PRAM reset which would have removed the default boot option which in this case appears to have been GRUB.

FYI, Dual booting any OS can be dangerous until you understand the other OS. Even then accidents can happen. If someone wants to dual boot an OS such as Linux, I would suggest trying it on a disposable system so if something goes wrong there is no data loss or down time and you can get a better understanding how macOS and Linux on a single drive. Only after a person is comfortable and confident in the OS should a dual boot be attempted on the main system. Also try the OS in a VM or install Linux to an external drive so it does not touch the main internal macOS.

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Answer 2

Halonk Author

Level 1

18 points

Apr 22, 2019 2:06 AM in response to HWTech

I tried all the "esc", "shift" and others. The computer would either go to the firmware prompt or OS Mojave would start as if nothing were done. The PRAM reset command had no effect whatsoever, computer just starting OS as if no keys were touched. In retrospect I do agree that playing around with dual boot were a foolish experiment. I have used dual boot with Ubuntu before and have had a positive impression of Ubuntu, but I tend to forget the adverse effects of the boot loaders on the computer (probably old age and a somewhat fatalistic approach).

In this case it was the "Snap" repository which blocked me out of my personal folders and files, leading to a botched repair attempt from a corrupted USB stick resulting in this predicament. I will take your advice and contact Apple to ask for (costly) help to remove the firmware password, as this situation is unacceptable - stupidly caused by myself. As for OS Ubuntu I am now in the market for a used, tolerably specced Windows laptop to use for my Linux experiments and probable untimely crashes.

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Recovery functions blocked by firmware password after installing rEFInd boot loader and Ubuntu partition

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