There are different ways to install Linux, most use the « legacy » mode, while other install the EFI mode but at the expense (IMHO) of very complex processes for a beginner or using Refind, which is OK but I prefer to skip additional tools when I can.
The advantages of EFI are the support of the additional SATA connectors, and based on my own experience, a better thermal and fan control without additional software on my own system (Mac 1,1 upgraded to 2,1 and a double quad-core X5355).
This tutorial explains how to achieve it quite easily (hopefully) based on the post of Sergey’s blog: http://blog.sergem.net/boot-ubuntu-18-0 ... macpro-11/
Requirements:
Flashdrive
Linuxmint ISO of your favorite flavour
Bootia32 : https://github.com/hirotakaster/baytail-bootia32.efi
Another PC (I used another Linuxmint)
We are going to use the “manual” way described by Sergey (with some minor differences).
1) Prepare the flashdrive partitions and folder
Create GPT partition table (in Gparted e.g.)
Create the EFI partition: FAT 210 MB, name EFI with boot flag
Create the Linux partition: EXT4 (several GB based on the drive size)
Create folders /efi/boot and /boot/grub on the EFI partition
2) Copy the relevant files to the EFI partition
Copy vmlinuz (kernel) and initrd.lz (initial ramdisk) from Linuxmint iso /casper folder to /boot/grub
Put the Grub2 bootia32.efi file to /efi/boot/grub (EDIT: corrected path to /efi/boot/grub as on printscreen)
Create a text file “grub.cfg” with the following content in /boot/grub
Code: Select all
set timeout=10
set default=0
menuentry "Install Mint64" {
fakebios
linux /boot/grub/vmlinuz boot=casper file=live-media-path=/casper/ ignore_uuid priority=low noefi nomodeset
initrd /boot/grub/initrd.lz
} 
3) Extract the content of the Live ISO to the EXT4 partition
4) Boot holding the ALT key and select the orange EFI Boot icon
Doing so enables to boot and install Linuxmint from the flashdrive.
However, at the post-installation reboot, it may be necessary to edit the grub entry (Escape then Edit) to add “noefi” in order to boot. Then you should also apply it permanently by editing /etc/default/grub and updating grub2. Some say it is no longer necessary, it was needed in my case.
And if you still end up with Minimal Grub command line, the easiest is to reboot on the LiveUSB drive, and use Boot-Repair to fix grub.
To check if the Mac has properly booted in EFI:
Code: Select all
[ -d /sys/firmware/efi ] && echo UEFI || echo BIOS
