Intel-based Macs that include an integrated Apple T2 chip feature enhanced security measures, such as Secure Boot, which controls what startup disks can be used. These models include:
- MacBook Pro introduced in 2018 through 2020, excluding MacBook Pro (13-inch, M1, 2020)
- MacBook Air introduced in 2018 through 2020, excluding MacBook Air (M1, 2020)
- iMac (Retina 5K, 27-inch, 2020)
- iMac Pro (2017)
- Mac mini (2018)
- Mac Pro (2019)
The Secure Boot feature ensures that only trusted operating systems can be used to start the Mac, which adds an extra layer of security to prevent unauthorized software from running at boot time.
To use the Mac OS X Basic and Mac OS X Minimal profiles, as well as an eDrive volume created with Techtool Pro on macOS 10.14 ‘Mojave’ through macOS 11 ‘Big Sur’, you will need to make changes in the Startup Security Utility. This can be done by starting up from the macOS Recovery partition by following these steps:
- Power on your Mac, then press and hold Command (⌘)-R keys immediately until you see the Apple logo appear. Your Mac is now starting up from macOS Recovery.
- When you see the macOS Utilities window, choose Utilities > Startup Security Utility from the menu bar.
- When you’re asked to authenticate, click Enter macOS Password, then choose an administrator account and enter its password.
- In order to start up from external disks, choose the “Allow booting from external media” and “No Security” options.
An example of the Startup Security Utility interface is below.
