Multiple operating systems on a MacBook Pro 28 Dec 2020
Booting from multiple operating systems on a mac can be a bit of a pain. This is a quick guide to be able to boot into OSX/Linux/Windows 10:
Resize disk via
Disk Utility: go to
Partition and resize the partition
where OSX is. Optional step: create partitions for Linux, Windows, and maybe an
extra one to easily transfer files between OSes.
Temporarily disable System Integrity Protection (SIP): reboot holding
Cmd+R, open a terminal, and type
csrutil disable. This is necessary for the
next step, otherwise the changes will keep being reverted.
Install gdisk and convert the partitioning scheme from
Install Windows 10 and/or your linux distro of choice. Depending on your distro, installing linux last will include Windows in the Grub configuration automatically. This may be useful if you intend to use Grub as the boot loader.
While Grub may pick up the Windows configuration, in order to boot into OSX,
you’ll have to hold the
option key while rebooting. If you don’t like this
behavior, after installing your linux distro, install rEFInd (e.g.
sudo apt install refind).
rEFInd will scan all drives for any bootable info
(e.g. EFI partitions, linux kernels, bootable USB sticks, etc) and allow you to
choose one at runtime.