When the BOOX64.EFI file executes, the software changes the EFI settings to make Ubuntu the default operating system to boot. This file is an exact copy of the /EFI/ubuntu/shim圆4.efi file stored in the same volume. (You hold down the option key at startup to access to the Mac Startup Manager.) The Startup Manager instructions the boot loader in the firmware to boot using the file /EFI/BOOT/BOOX64.EFI file in the FAT32 formatted volume in the EFI partition. I will post my successful attempts below.īy default, Ubuntu can be accessed from the Mac Startup Manager by selecting the icon labeled EFI Boot. The ultimate goal : having a trial-boot by adding Windows on BootCamp. If I want to switch to Ubuntu, I'd like to select it from the boot menu. In other words : when I power on my Mac, I want my default OS to be MacOS.

Formatting the hard drive to make it Mac-compatible (HFS, HFS+) via Ubuntu (through GParted for instance) is far from easy because the Mac packages aren't available: you have to search & install them.īasically I'm trying to have a dual-boot system (MacOS & Ubuntu) without affecting my EFI settings.

If you delete the EFI settings (= EFI partition on your hard drive), your device cannot boot on this OS and often leads to a black screen or equivalent at startup.

*The EFI settings are - simply put - what allows your device to boot on a given OS. When installing Ubuntu through a USB flashdrive via the mac boot menu, the Ubuntu installer has this annoying habit of replacing the original Mac EFI settings* with Ubuntu EFI settings*.Initially, I was aiming at dual-booting MacOS and Ubuntu on a Macbook Pro, which worked after few attempts but it had its major flaws :

I encountered this issue quite often and tested a few solutions so I hope this will help.

Macbook boot usb key