MacOS – using rEFInd to get around lack of boot screen when using unsupported GPU in Mac Pro

efimac promacos

I am trying to upgrade a 2012 Mac Pro (model 5,1) to Mojave. I have installed High Sierra and updated bootrom to MP51.0089.B00. I've got a required "metal capable" graphics card (Sapphire PULSE Radeon RX580), which unfortunately does not support the Startup Manager. I want access to the Startup Manager, to be able to access recovery partitions and bootable external media.

My plan: rEFInd seems like a good solution to my problem. Before installing the unsupported GPU, if I can get rEFInd to appear as an option in the Startup Manager, I can select it as the default using the control key when selecting the boot option (this does work on my machine). Then once I install the unsupported GPU, the rEFInd main screen will appear on startup and I can select whatever I want, including recovery partitions and external media. (Obviously I must be careful never to change the default in SystemPrefs->StartupDisk, or I'll have to temporarily re-install the old GPU and change the default back to rEFInd !). Does this sound like a workable plan ?

I've installed rEFInd, with default options, and it does not appear in Startup Manager. To get it to appear in Startup Manager, I believe I need to reinstall it with the –usedefault option. How do I reinstall ? Do I need to uninstall first (since I first installed it without the usedefault option) ? Uninstalling looks somewhat problematic. And what argument do I need to use with –usedefault ? I've looked at a wiki and a manpage, but am still confused. When I ran 'mountesp', I got:

sudo mountesp
The ESP has been identified as /dev/disk0s1; attempting to mount it....
The ESP is mounted at /Volumes/ESP

The only file in that volume is: /Volumes/ESP/EFI/APPLE/EXTENSIONS/Firmware.scap

That's it. I am out of my depth, and would appreciate help.

Best Answer

Removing rEFInd from the EFI partition.

If you use refind-install without any options and/or the --usedefault option to install rEFInd into the EFI partition (disk0s1), then use the following steps to remove rEFInd from this partition.

  1. Make sure the EFI partition (disk0s1) is unmounted. Use the command given below.

    diskutil unmount disk0s1

  2. Mount the EFI partition (disk0s1). The command is given below.

    sudo diskutil mount disk0s1

  3. Use the Finder to open the EFI folder on the EFI volume.

  4. If any of the following folders exist in the EFI folder, then move each folder to the trash: BOOT, refind and tools

    In other words, if the any of the following folders exist, then the folder should be removed.

    /Volumes/EFI/EFI/BOOT
/Volumes/EFI/EFI/refind
/Volumes/EFI/EFI/tools

  5. Empty the trash.

  6. Use the command given below to unmount the EFI partition.

    diskutil unmount disk0s1

Installing rEFInd to appear in the Mac Startup Manager

Note: If rEFInd already exists in the EFI partition (disk0s1), then the instructions given in this section may fail. You should make sure rEFInd is removed from the EFI partition (disk0s1) before proceeding.

The commands to install the current version of rEFInd is given below. You should enter these commands from macOS.

sudo $HOME/Downloads/refind-bin-0.12.0/refind-install --usedefault /dev/disk0s1
diskutil unmount disk0s1

Below is the output when the above commands were entered using the current version of Catalina (macOS 10.13.6).

Note: When testing, I received the error message sed: -i may not be used with stdin. This error did not effect the installation of rEFInd other than not unmounting disk0s1

The rEFInd Boot Manager should now appear in the Mac Startup Manager with the label EFI Boot. Both the icon and label can be customized.

Related Question