Use a Mac OS X installation Disc. If you’re unable to use Internet Recovery Mode or create a bootable USB installer, you can still use a Mac OS X installation disc. These discs are available for OS X Snow Leopard, OS X Lion, and OS X Mountain Lion. If your Mac is from 2012 or earlier, there was an installation disc in the original box. To access OS X Recovery, reboot the computer while holding the Option key. Select Recovery HD from the Startup Manager. 'Note: In order to create an external OS X Recovery using the OS X Recovery Assistant, your Mac must have an existing Recovery HD, which in your case it most likely already does. Catalina is the latest build of Apple’s MacOS operating system, version 10.15. Released in October 2019, it’s packed with plenty of new features Mac owners should love, like spreading cloud.
Apple Silicon Macs started to arrive in customers hands on Tuesday November 17th, 2020. One of the first things we need to understand is how to reinstall or factory erase macOS on Apple Silicon. All the old rules that you had to follow with Intel Macs has now changed. I will show you 3 different ways to reinstall macOS Big Sur on a Apple Silicon Mac.
If you are looking for more information on Apple Silicon Macs, I’ve wrote an article going over everything you need to know.
Right off the bat, we need to understand that Mac Internet Recovery on Apple Silicon is DEAD! Finally you don’t have to worry about IR errors and the problems that come with them.
Internet Recovery will still remain for Intel based Macs. For Apple Silicon we now have 4 different ways to reinstall macOS.
Apple Silicon macOS Recovery is almost exactly the same as it is on Intel Based Macs. One of the major things that has changed is the way that you get into macOS Recovery. Instead of having to remember a bunch of keyboard commands you can now use the power button to get right to the boot picker macOS recovery menu!
The video above shows you how to factory restore / erase your Apple Silicon Mac and reinstall macOS.
Apple Silicon System Recovery is a new hidden recovery option in addition to macOS Recovery. If for some reason macOS Recovery becomes corrupt, System recovery will load which is the same as macOS recovery. You can use it to reinstall macOS and macOS Recovery.
If something serious goes wrong with your Mac and it can’t boot into macOS you will see a new startup screen. (The blinking folder icon has been retired). You will now see a screen like this
This screen has a new Apple Support URL support.apple.com/mac/restore which will tell you that you need to restore macOS firmware via Apple Configurator 2 and a 2nd mac running 10.15.6 or newer. Restoration will now work the same on the Mac as it does on iOS iPhones and iPads.
On Apple Silicon external boot remains, but has changed.
External Boot for the macOS installer is now enabled by default
You no longer need to enter Security Options to enable External Boot!
Now you can build out an USB Installer of macOS Big Sur and boot your Apple Silicon Mac to it.
If all options to reinstall macOS fail you can now use Apple Configurator 2.
This will help with rapid deployment in lab / school situations.
My Mac T2 BridgeOS Restore article will show you this process. It has not changed except for one thing. In the future the “RESTORE” option will automatically download the newest macOS ISPW file for you and install it. For now you will need to download it and and drag it over to the DFU icon.
I’ve also written an article that goes over the entire new DFU + Apple Configurator 2 Apple Silicon Restore process below.
New Apple Silicon Macs now have 2 Security modes.
1.Full Security = “iOS Security” – Only the latest signed version of macOS can be installed on an Apple Silicon Mac.
Full Security
Ensures that only your current OS, or signed operating system software currently trusted by Apple, can run. This mode requires a network connection at software installation time.
WWDC 20202. Reduced Security = Any version of macOS that was signed by Apple.
Reduced Security
Allows any version of signed operating system software ever trusted by Apple to run.
WWDC 2020With the new Apple Silicon Security Policy, you can set a security policy for each container! On an Intel based Mac the security policy would be set on the entire system.
Will you be able to install older versions of macOS? A quick review;
Yes! But only with your Macs M1 Security Policy set to “Reduced Security”.
Caveats
I started a new database page that will keep track of all macOS Apple Silicone IPSW Firmware files.
The article will include
Starting with Apple Silicon, macOS OTA (Over The Air) Firmware will be signed by Apple. This means that they control which version of macOS can be installed on your Mac. The difference this time around is that Apple gives us the option to turn Signed Checking OFF. So you will still be able to install older versions of macOS.
Apple Silicon macOS Reinstall