[SOLVED] will efibootmgr brick my Intel Mac mini?

wowbaggerHU · 02-04-2017, 04:41 PM

Hello Everyone,

I recently bought a late 2012 Mac mini, and I by now managed to install Slackware64 14.2 on it.
The install was done in UEFI native mode, the partition layout is GPT, and I installed elilo as the default boot location on the EFI System Partition. (/boot/bootx64.efi)
Currently Slackware is the only OS on the machine, and I intend to keep it that way.

The system works fine, but I haven't installed a boot menu entry for elilo, and I have to rely on the fallback/default boot loader location for the machine to pick up elilo.
Installing the bootloader entry is explicitly contraindicated in README_UEFI.TXT, saying that efibootmgr might brick my Mac Mini.

"Next you'll be asked if you want to install a new menu
entry for your Slackware system in your UEFI firmware. Unless you are using
an Intel Mac, it is suggested that you do this. ...
... If you are using an Apple Intel Mac, DO NOT TRY TO
INSTALL A MENU ENTRY! It would probably brick your firmware requiring Apple
to service the machine to reflash the firmware. On other machines that use
UEFI, it is highly recommended to add the menu entry to make it easier to
chose an operating system at boot."

This warning is still present in the slackware-current file too.
Is it still dangerous in 2017 to try and use efibootmgr on a late 2012 Mac mini?
Is there maybe a more recent version of efibootmgr that works better with Intel Macs?
Have any of you used efibootmgr to install a boot entry on Intel Macs? Did it work for you?

Thanks for your help!

khronosschoty · 02-04-2017, 11:42 PM

I recommend using refind. SlackbBuilds.org has a script for it. https://slackbuilds.org/repository/1...?search=refind

laprjns · 02-05-2017, 09:25 AM

If you are trying to avoid using efibootmgr to set a boot menu entry, then don't install rEFInd using Slackware since the rEFInd installer script uses efibootmgr to set rEFInd as the default boot option. It looks to me like the people who install rEFInd on a Mac do so from the Max OS where the rEFInd installer uses bless.
Since you are only going to use Slackware on this computer, then why take the chance of changing anything, just boot using the /boot/bootx64.efi

khronosschoty · 02-05-2017, 09:29 AM

Quote:

Originally Posted by laprjns

If you are trying to avoid using efibootmgr to set a boot menu entry, then don't install rEFInd using Slackware since the rEFInd installer script uses efibootmgr to set rEFInd as the default boot option. It looks to me like the people who install rEFInd on a Mac do so from the Max OS where the rEFInd installer uses bless.
Since you are only going to use Slackware on this computer, then why take the chance of changing anything, just boot using the /boot/bootx64.efi

Oh wow, I over looked that. I have installed refind from within Slackware, and had no issues with my Macbook pro 13" mid 2010.

wowbaggerHU · 02-05-2017, 02:35 PM

Quote:

Originally Posted by laprjns

Since you are only going to use Slackware on this computer, then why take the chance of changing anything, just boot using the /boot/bootx64.efi

That is exactly what I'm doing currently.

I was just wondering whether that efibootmgr vs Intel Macs thing is still real. Maybe someone here has already tried it, and made it work with the Mac model I currently have.
I also was curious about the origin of this warning. Perhaps where this warning originally came from, I could get exact model mumbers where it did not work.

Currently efibootmgr lists the current bootloader config:

Code:

root@mac-mini:~# efibootmgr -v
BootCurrent: 0000
Timeout: 5 seconds
BootOrder: 0080
Boot0080* Mac OS X      ACPI(a0341d0,0)PCI(1f,2)03120a00000000000000HD(2,64028,7456ce40,aee237d2-0eb7-4fe3-8f86-c166ebcbd205)
BootFFFF*       ACPI(a0341d0,0)PCI(1f,2)03120a00000000000000HD(3,69ac6d88,6400000,00001686-2f71-0000-952a-0000ec450000)File(\System\Library\CoreServices\boot.efi)

I'm also wondering whether the EFI boot timeout could be modified safely with this model.
Could someone please confirm?

Didier Spaier · 02-05-2017, 06:11 PM

I wouldn't take the risk. Anyway it wouldn't hurt to update your firmware including this securitu update. https://support.apple.com/kb/DL1823?locale=en_US

Also, if you firmware includes a EFI shell (no idea if tht's the case) installing in /efi/boot/EFI a startup.nsh file giving the path to elilo could speed up the boot a bit. If not, that won't hurt. Just type as root:

Code:

echo "EFI\Slackware\elilo" > /boot/efi/startup.nsh

wowbaggerHU · 02-14-2017, 02:56 AM

In the end, I used the OSX installer, to "bless" my elilo boot loader.

The details can be found here: http://www.linuxquestions.org/questi...lo-4175599636/

khronosschoty · 02-14-2017, 03:43 AM

Quote:

Originally Posted by wowbaggerHU

In the end, I used the OSX installer, to "bless" my elilo boot loader.

The details can be found here: http://www.linuxquestions.org/questi...lo-4175599636/

Smart move IMO.