UPDATE 01/02/21 – This article is only for Apple Silicon M1 Macs
Use a USB installer with Big Sur 11.2 to reinstall macOS
Enter macOS recovery. If you have FileVault 2 enabled, click the Recovery Assistant menu and then select “Erase Mac”. If you don’t have FileVault 2 Enabled or have already erased the drive, click utilities from the top menu bar and then click Terminal. Enter in the command resetpassword This will bring you back to the Recovery Assistant menu. Click the Recovery Assistant menu bar item at the top and then select “Erase Mac”.
UPDATE 11/19/20 – It looks like Apple has fixed the issue! I’ve just finished reinstalling macOS Big Sur from macOS Recovery and from a USB Installer drive. Everything works now!
UPDATE 11/18/20 –I originally reported that this error would happen on a factory build of Big Sur 11.0 (20A2411) but it also happens if you are running 11.0.1 (20B29). To review…
It doesn’t matter if you are using macOS Recovery or Big Sur USB Installer, you will be unable to reinstall Big Sur!!!
The only way to recover is by using a 2nd Mac with Apple Configurator 2!!
When the macOS is reinstalling the Mac will attempt to personalize the version that is being installed. You will get this error.
An error occurred preparing the update. failed to personalize the software update. Please try again.
macOS Big Sur Reinstall on an Apple Silicon Mac running the shipping version 11.0 (20A2411) Credit MacRumors Forum user craigslorach.
Mr. Macintosh Update video on the issue with additional steps.
Mr. Macintosh video that explains the issue.
Can this issue be fixed?
YES! The ONLY way to fix this issue is to use Apple Configurator 2 and reinstall macOS with a 2nd Mac.
How to Reinstall macOS on your Apple Silicon Mac. – Everything you need to know!!
Apple Silicon M1 Mac Recovery has changed! The interface, options and the way you reinstall macOS is all new. I will show you everything you need to know.
UPDATED 09/25/21
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.
1. macOS Recovery = First line of recovery.
2. System Recovery = Hidden partition for when normal macOS recovery is not available.
3. macOS Big Sur USB Installer Drive. = Boot to a createinstallmedia based Big Sur full installer.
4. macOS System Restore via DFU mode + Apple Configurator 2.
Reinstall macOS on Apple Silicon Table of Contents
1. macOS Recovery
2. macOS System Recovery
3. Both macOS Recovery and System Recovery are not available?
4. macOS Big Sur USB Install Drive
5. How to Use Apple Configurator 2 to reinstall macOS on Apple Silicon
6. Apple Silicon Security Policy
7. Apple Silicon Compatible Versions of macOS
8. Can I downgrade macOS on Apple Silicon?
9. Where can I get macOS ISPW Firmware files?
10. Signed? What does that mean?
1. Apple Silicon macOS Recovery
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!
Mr. Macintosh video on how to get to the macOS recovery menu on Apple Silicon Macs
Mr. Macintosh How to – Boot to recovery + Erase & Reinstall macOS on your Apple Silicon M1 MacBook Pro & MacBook Air!
Mr. Macintosh How to Video – Boot to Recovery + Erase & Reinstall macOS on Apple Silicon Mac Mini M1. I will also show you how to boot from a Big Sur USB installer to reinstall macOS twice as fast!
The video above shows you how to factory restore / erase your Apple Silicon Mac and reinstall macOS.
First line of defense, is macOS Recovery.
2. Apple Silicon System Recovery
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.
3. Both macOS Recovery and System Recovery are not available?
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
Apple Silicon Startup problems – Prohibited sign – Credit Martin Nobel – https://twitter.com/martinnobel_/status/1321645315502432256
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.
4. Apple Silicon External Boot Options – USB Installer
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.
Mr. Macintosh Video on how to create a macOS Big Sur USB Install Disk for Apple Silicon or Intel.
Mr. Macintosh Video on how to use a USB Installer to reinstall macOS on Apple Silicon!You can now boot a USB macOS installer without enabling external boot in Security options! It’s enabled by default.
5. How to Use Apple Configurator 2 to reinstall macOS on Apple Silicon
If all options to reinstall macOS fail you can now use Apple Configurator 2.
1. Revive = Will restore macOS Recovery Only. (User data remains)
2. Restore = Will will download macOS and macOS recovery and reinstall them (THIS WILL ALSO ERASE YOUR HARD DRIVE)
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.
Mr. Macintosh quick overview video on how to boot your Apple Silicon Mac to DFU mode. I will also show you how to reinstall macOS in 10 minutes with Apple Configurator 2 and a 2nd Mac.
How to reinstall macOS on a M1 Mac Mini UPDATED VIDEO!
Mr. Macintosh Deep Dive video that goes over the entire process and explains how the enter DFU and Apple Configurator 2 works + Troubleshooting!
How to install macOS on multiple Apple Silicon M1 Macs in about 10 minutes!
I’ve also written an article that goes over the entire new DFU + Apple Configurator 2 Apple Silicon Restore process below.
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 2020
2. 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 2020
With 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.
New Apple Silicon Security Policy can be set differently on each container.
7. Apple Silicon Compatible Versions of macOS
Will you be able to install older versions of macOS? A quick review;
Full Security = iOS based security, only the latest signed version of macOS can run on the system.
Reduced Security = Any version of macOS that was signed by Apple can run on Apple Silicon
Note: The shipping OS version will be the oldest OS available to install
8. Can I downgrade macOS on Apple Silicon?
Yes!
Note. The “Shipping version” of macOS on Apple Silicon is the lowest OS that can be installed. An example of this is the M1 iMac which came with 11.3. You can not install Big Sur 11.2 on it.
9. Where can I get macOS ISPW Firmware files?
I started a new database page that will keep track of all macOS Apple Silicone IPSW Firmware files.
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.
