I wanted to install Linux on a portable SSD I had and make it bootable from my Macbook, so it needed UEFI support. I didn’t find a nice method of doing it online, so I found my own way.
Before going over the instructions, I’ll touch base on the difference between BIOS, EFI and UEFI. These are all methods of booting an operating system. BIOS is the legacy boot mode found on older computers. Newer computers, such as my Macbook, uses UEFI (which is the successor to EFI) which requires some more steps than BIOS when installing the OS.
To make a UEFI Linux install bootable, the drive must have a EFI boot partition, which is a FAT32 formatted partition that is at least 200MB big. To do a UEFI install, the install disk must also be in UEFI mode (if its not, it will not install a UEFI version of linux).
Most methods I found online involved booting the system via the Live CD and installing the operating system onto the connected external HDD. However what I found is this will overwrite the boot loader on the computer’s internal drive, thus after the install the drive must be repaired to make the machine bootable again.
My solution is to create a virtual machine (using VirtualBox) to boot the Linux Live CD from and install the OS and install the operating system onto the external HDD within the VM. This approach won’t affect the internal drive in any way (as the VM is completely sandboxed) and should work with most Linux operating systems.
vboxusers group using
sudo usermod -aG vboxusers $USER, make sure to reboot to refresh the groups