Hopefully QEMU, Parallels & VMware are not far behind.
I will walk you through the entire process. (UPDATE!KhaosT just released an updated GUI interface, more info at the bottom of the article)
Requirements & Instructions (Modified Original Instructions)
Download links are at the bottom.
Apple Silicon M1 Mac (running macOS Monterey)
Xcode 13 (Beta)
Apple Configurator 2
macOS Monterey IPSW
Empty dmg image (This will be your system storage, name it disk.dmg, you can create it from Disk Utility)
First Time Setup
1. Clone this project from Github save as zip for use in Xcode. Open zip in Xcode Beta.
2. Click the Run Button (VM will build)
3. Quit the app when “Virtual Machine” window showed up, move disk.dmg into the app’s container
4. Run it again
5. Open Apple Configurator 2, if everything works, There should have a VirtualMac in DFU mode
6. Temporary disable macOS Firewall and iCloud Private Relay (Apple Configurator 2 can’t restore VM with those features enabled) Both are default off if you did not turn them on or sign in with your AppleID
7. Drag macOS 12 IPSW file into Apple Configurator 2, click Restore to install macOS
8. When AC2 finishes the install you should be done and your vm should boot to macOS 12 Setup Assistant!
UPDATE!
KhaosT just released a new update to his code that gives us control over the VM Settings.
You can now upgrade or downgrade BridgeOS on your Intel T2 Mac with an IPSW file & Apple Configurator 2!
As soon as Apple released the very first T2-equipped Mac, MacAdmins wished that they had a way to downgrade BridgeOS. You can now even downgrade BridgeOS on a T2 Mac up to 7 days after an update!
UPDATED: 6/07/22
BridgeOS IPSW Downloads
In the chart below is a list of previous BridgeOS IPSW files along with the signing status. (Signed = You can upgrade or downgrade) All links are Apple Software Update direct downloads.
You can downgrade BridgeOS to one previous version (with in 7 days of a new os update) if you are having issues or would like to test the software update mechanism. The requirement for BridgeOS downgrade is that you need to satisfy the minimum OS Version or newer.
Why would anyone want to downgrade BridgeOS?
Example – You updated to macOS Big Sur 11.2.3 from 11.1. Something in the new version of bridgeOS is causing problems on your T2 Mac. You now want to downgrade to a previous version so you can single out the issue. You will need to downgrade macOS down to 11.2 to support the previous version of BridgeOS. If you downgrade BridgeOS to an older version than the installed OS then macOS Big Sur will not boot and you will be prompted to update BridgeOS from the macOS Update Assistant environment. After downgrading BridgeOS you will need to reinstall/downgrade 11.2 over the top of 11.2.3, or reinstall 11.2. You will now be running 11.2 and the matching bridgeOS version 18P4346.
NOTE! You can only downgrade back one previous version. Apple usually supports T-1*, current minus one version. *Apple will usually leave the previous version of BridgeOS signed for about 7 days after the release of a new update. The BridgeOS signing schedule follows iOS. (Apple will unsign previous versions of iOS about one week after a new update)
How to Downgrade BridgeOS on a T2 Mac
If you would like to learn how to do this, click on the link below!
You can now downgrade BridgeOS on your T2 Intel Mac (2017-2020) to a previous version with Apple Configurator 2!
Ever since Apple released the very first T2 equipped Mac, some users wished that they had a way to downgrade to the previous version of BridgeOS.
The problem?
Updating BridgeOS on a T2 Mac was a one way street. You could only upgrade not downgrade.
Why would anyone want to downgrade BridgeOS?
Downgrading BridgeOS for troubleshooting & macOS Update workflow testing.
Let’s go over a quick example of why you might want to downgrade BridgeOS. You updated to macOS Big Sur 11.4 from 11.3. After the update, you’ve found that something is not working right. The T2 chip handles many things including, fan speed, battery, power, charging & sound (speakers & microphone). So in this example, maybe you are getting audio cracking noise (has happened in the past). Now you thinking that the new version of bridgeOS might be causing problems on your T2 Mac.
The 2nd example is macOS Update testing. If you are a system administrator in charge of updating a large fleet of Mac testing is very important. Part of that macOS Update process is updating BridgeOS. An example of this is if you upgrade a T2 Mac from 11.3 to 11.4. BridgeOS is updated in the process. Now that this T2 Mac is on the latest version of BridgeOS it normally can not be downgraded. Even if you boot back to recovery and install 11.3, BridgeOS will remain the same updated version. Set this Mac on the shelf because you will never be able to take it through a full update process again until 11.5. Now you want to downgrade to a previous version of BridgeOS so you can single out an issue or test the full update process again.
Apple Configurator took care of all the work in both above examples, downloading the prod/final version of BridgeOS for your hardware.
This is different.
We can now download full BridgeOS IPSW Files directly from Apple the same way we do now with Apple Silicon M1 Macs. We can then use the BridgeOS IPSW File to restore/revive BridgeOS to your T2 Mac. The difference here is that Apple WILL stop signing for previous versions of BridgeOS. The signing process follows iOS and is canceled usually about one week after the release of a new update. Apple leaves ONE previous version signed (for 7 days) so you can now downgrade to that version!
BridgeOS and macOS Version Caveats
The first thing to know about BridgeOS is that it has macOS version requirements. BridgeOS supports the macOS version that’s released alongside it. The BridgeOS version also supports previous versions macOS. Let’s go over an example.
After updating to Big Sur version 11.4, you are now are having issues with your speakers (sound processed through T2 chip). You want to downgrade to the 11.3 compatible version of BridgeOS to see if that fixes the issue. You can now downgrade! The only problem is, the 11.3 version of BridgeOS does NOT support newer versions of macOS. You will need to downgrade to the minimum version of macOS that is supported by the version of BridgeOS that you are trying to downgrade to. You now need to downgrade macOS to version 11.3 to support the previous version of BridgeOS. If you don’t downgrade macOS to a compatible version and attempted to boot your Mac, you would be immediately prompted to update BridgeOS. The Mac would boot into “macOS Update Assistant” and would then download the latest compatible BridgeOS update and install it for you.
After downgrading BridgeOS you will need to reinstall/downgrade 11.3 over the top of 11.4 or erase and install 11.3 again. You will now be running 11.3 and the matching bridgeOS version 18P4556.
BridgeOS Version Compatibility Continued
I built a table to help visualize the current situation.
This table shows how BridgeOS version 18P4556 is compatible with macOS version 11.0.1 – 11.3.1. A forced BridgeOS update will be triggered if macOS 11.4 or newer is installed.
NOTE: Point/dot releases (example 11.3.1) may or may not come with an associated BridgeOS update. Big Sur 11.3.1 is compatible with the 11.3 version of BridgeOS
T2 Mac BridgeOS IPSW
MacOS
Signed
Version
Date
5.4_18P4663_Restore.ipsw
11.4
YES
18.16.14663
5/24
5.3_18P4556_Restore.ipsw
11.3
NO
18.16.14556
4/26
5.2_18P4347_Restore.ipsw
11.2.2
NO
18.16.14347
2/25
5.2_18P4346_Restore.ipsw
11.2
NO
18.16.14346
2/01
5.1_18P3030_Restore.ipsw
11.1
NO
18.16.13030
12/14
5.0.1_18P2561_Restore.ipsw
11.0.1
NO
18.16.12561
11/12
The table above lists the IPSW file version and build number. The next section is the maximum minor release that is compatible.
The BridgeOS Version in the 4th section matches what is listed in System Profiler (System Firmware Version), followed by the release date and size.
You can only downgrade back one previous version. Apple usually supports T-1, current minus one version. Normally when a new version of BridgeOS is released the the previous version of BridgeOS is unsigned after 7 days and cannot be installed.
My T2 Intel Mac BridgeOS Download Database –> LINK
1. Download the version of BridgeOS IPSW file that you want to install
2. Boot the target T2 Mac into DFU Mode
3. Connect both Macs with USB-C white Apple charge cable.
4. Open Apple Configurator 2
5. Drag BridgeOS IPSW File over to DFU icon.
6. You will be prompted to Restore or Revive
7. Restore = Click Restore (erases all data)- downgrade BridgeOS (you can then reinstall macOS from Recovery
8. Revive = Click Revive (etains all data) – downgrades BridgeOS (you will need to install previous compatible version of macOS over the top of the current version)
9. Done! You are now on a previous version of BridgeOS.
This is what it looks like to drag a BridgeOS IPSW file over the DFU icon in Apple Configurator 2.
The Restore/Revive menu after dragging the BridgeOS IPSW file over to Apple Configurator 2.
This is what happens when you attempt to restore/revive with an unsigned version of BridgeOS.
The System cannot be restored on this device. The system install could not be authorized for this device. The build may not be approved for production installs.
You can now remove the firmware password (+ erase all data) on a T2 Mac without Apple Support if you forgot it.
In this article, I will go over the history of the firmware password on Intel Mac computers. After that, I will show you a new way how to remove the firmware password (and erase your data) on a T2 Mac from 2018-2020. (Scroll to section 6).
NOTE: This information is only for 2006-2020 Intel Mac computers. Apple Silicon M1 Mac Devices do not have a firmware password.
I will also go over my recommendations on how you can protect your data at the end of this article.
I will answer the following questions.
What does setting a firmware password on a Mac do?
What are the differences in firmware passwords from the following years – 2006-2010, 2011-2017 & 2018-2020?
How to you set the firmware password in recovery.
How to Enable & Disable Firmware Password in macOS.
What can you do if you forget the firmware password?
How to remove the firmware password with Apple Support.
Removing the firmware password on a T2 Mac with Apple Configurator 2.
How long was this new way possible? Does anyone at AppleCare know about this?
What does this mean for education, small & large companies, home users, computer recyclers, and criminals?
With Apple Silicon Macs, you can install macOS just like you can with iOS! I will show you how to boot your Apple Silicon Mac into DFU Mode so you can Restore macOS.
UPDATED 06/04/21
This article will go over how to restore macOS on your new Apple Silicon Mac. Your first line of defense for installing macOS on Apple Silicon should be macOS Recovery. But if for some reason you are having problems with that you can boot your Apple Silicon Mac with a Big Sur USB installer drive. I wrote an article covering all the changes to macOS Recovery here.
Order of that you should follow for reinstalling macOS on Apple Silicon.
1. macOS Recovery – Hold down the power button to enter the Boot Picker Menu (downloads macOS Big Sur over the internet 1-2 hours)
2. System Recovery – (Separate hidden partition – Will boot automatically if macOS Recovery is erased or damaged)
3. macOS Big Sur USB Installer Drive – External boot for macOS Installers is enabled by default on Apple Silicon – (Installs from USB 30-40 Min)
4. Apple Configurator 2 REVIVE option – This option will reinstall macOS Recovery if erased or damaged (retains user data on the hard drive)
5.Apple Configurator 2 RESTORE option – This option will Reinstall macOS Recovery, ERASE your hard drive and reinstall macOS (Fast install! 10 min)
Use macOS Recovery on a Apple Silicon M1Mac
Keep in mind, just like last time, some of the instructions for booting your Apple Silicon Mac are confusing. If you thought booting to DFU mode was a little difficult on T2 Macs… wait until you try on Apple Silicon. For one thing the ports used are the exact opposite of what was used on T2 Macs! Plus the process to get the Mac into DFU mode has changed! That’s why I’m writing this article, to better explain the instructions.
Table of Contents
1. Updates
2. List of Apple Silicon Compatible Macs
3. Setup and Cable Requirements before you begin
4. Download Apple Configurator 2 app
5. How to Boot your Apple Silicon Mac into DFU Mode
6. Which Firmware version is your Mac on?
7. Instructions for the M1 13″ MacBook Pro & Air (2020)
8. Instructions for the M1 Mac Mini (2020)
9. Instructions for the M1 24″ iMac (2021)
10. You made it! Apple Configurator 2 Steps
11. Download macOS ISPW file
12. Begin Apple Silicon macOS Revive / Restore
13. Finishing Up
14. Can I Downgrade from an older version of macOS via IPSW Files?
UPDATE 4/13/21 – New DEEP DIVE video on using Apple Configurator 2 to reinstall macOS on multiple M1 Macs.
UPDATE 3/17/21 – I’ve added a new video that shows you how to use Apple configurator 2 to install macOS on multiple M1 Macs.
UPDATE 1/14/21 – Apple has released Apple Configurator 2 Version 2.13.3, be sure to update. I’ve also added a new Apple Silicon Mac Mini M1 Video above.
UPDATE 11/18/20 –Apple has released Apple Configurator 2 Version 2.13.2! Make sure you update. If you are still running 2.13.1 or below you will get an error when you click the restore button.
UPDATE 11/17/20 –Added a new section #6 to explain the problem booting to DFU mode if your Apple Silicon Mac is on it’s factory firmware of 6723.41.11
This is a list of Apple Silicon Macs that this process is compatible with.
1. 2020 M1 13″ MacBook Pro
2. 2020 M1 MacBook Air
3. 2020 M1 Mac Mini
4. 2021 M1 24″ iMac
3. Setup and Cable Requirements before you begin.
You will need to meet the following requirements –
(The Host Mac will do the work and the Target Mac is the Mac you need to Restore)
1. USB-C Mac as the Host Machine.
2. The Host Mac must have at least macOS 10.15.6 and Apple Configurator 2.13.1 or newer installed.
3. Internet access on the Host Mac – “You may need to configure your web proxy or firewall ports to allow all network traffic from Apple”
4. USB-C to USB-C Cable – The white Apple USB-C Charge will work fine. (USB-C Cable MUST Support Power & Data). Apple notes that a Thunderbolt 3 to Thunderbolt 3 cable is not supported but I’ve tested it and it works fine.
5. The Host Mac can have the cable plugged in anywhere.
6. The Target Mac MUST have the USB-C Cable Plugged in to the Left Hand side USB-C port. For Laptops the port closest to the back of the Mac or screen) For the Mac Mini it’s the port closest to the ethernet port. (BOTH LOCATIONS ARE OPPOSITE of the T2 Mac BridgeOS restore locations!)
If you don’t meet all the prerequisites booting to DFU Mode or Upgrading macOS Firmware might fail.
4. Download Apple Configurator 2
If you do not have Apple Configurator 2, you can download it now from the Mac App Store with this link.
5. How to Boot your Apple Silicon Mac into DFU Mode
With all the startup keyboard commands you can issue a Mac, booting into DFU Mode should be pretty simple right?
NOPE! (x2 this time for Apple Silicon!)
You have to follow a very particular sequence to get this to work. I have attempted to find the exact way to get this to work every time. Even then sometimes the system will refuse to Boot into DFU mode.
Apple’s Instructions
You can find Apple’s instructions for booting into DFU mode here.
If these instructions do not work fo you continue below.
Press the power button.
While holding down the power button, at the same time press all three of the following keys for about 10 seconds:
The right Shift key
The left Option key
The left Control key
After 10 seconds, immediately release the three keys but continue to hold down the power button until it appears in Apple Configurator 2.Note: You won’t see any screen activity from the Apple notebook computer.
6. Which Firmware version is your Mac on?
Did you update your Mac to Big Sur 11.0.1 from 11.0 when it arrived? If you didnt the firmware will be
6723.41.11
To find the firmware version click the Apple icon > About this Mac > System Report.
Look for System Firmware Version.
If you are on Big Sur 11.0 and firmware version 6723.41.11 you will need to boot to the macOS Recovery selection screen first before attempting to boot into DFU mode.
If you updated your Mac to 11.0.1 and are running Firmware Version 6723.50.2 or newer you can follow the normal instructions. You can boot to DFU mode from power off instead of booting to the macOS recovery selection screen first.
7. My Instructions for the M1 13″ MacBook Pro & MacBook Air
It has proven difficult to get an Apple Silicon Mac into DFU mode. You could try Apple’s instructions above multiple times and STILL not get into DFU mode.
Once you have meet all of the pre requisites above, follow the instructions below to should get you into DFU Mode every time.
1. The Target Mac must be OFF to begin.
2.Hold down the Power button,RightShift, Left Control and Left Option keys for 10 Seconds (count 1 one thousand) then let go of every key except for Power . Keep holding down the power button for an additional 8 seconds until you get to 18 seconds total. If you count more than 20 seconds and don’t see the DFU icon, you will have to try the process again.
3. When the Target Mac is booted into DFU mode correctly, the host will show a big DFU icon in Apple Configurator 2.
4. After you see the DFU picture pop up on the AC2 Host Mac you can let go of the Power Button.
8. Instructions for the M1 Mac Mini (2020)
The Mac Mini 2020 instructions are to use the USB-C port is closest to the Ethernet port.
1. Disconnect the power cord from the Mac Mini.
2. Plug USB-C/Thunderbolt cable into the USB-C port next to the ethernet port.
3. Plug the other end into the Host Mac.
4. While holding down the power button, connect the Mac Mini to power and continue to hold the power button for about 3-5 seconds
5. You should now see the DFU logo on the Host Mac.
9. Instructions for the M1 2021 24″ iMac
The 24″ M1 iMac (2021) instructions are to use the USB-C port is closest to the magnetic power port. The instructions are the same for both the 2 and 4 port version.
1. Disconnect the magnetic power cord from the iMac.
2. Plug USB-C cable into the USB-C port next to the power port.
3. Plug the other end into the Host Mac.
4. While holding down the power button, connect the iMac magnetic power plug continue to hold the power button for about 3-5 seconds
5. You should now see the DFU logo on the Host Mac.
10. Instructions for the M1 2021 24″ iMac
11. Instructions for the M1 2021 14″ and 16″ MacBook Pro
12. Instructions for the M1 2022 Mac Studio
10. You made it! Apple Configurator 2 Steps
The hard part is now over. Now we can restore macOS on the Target Mac. When you first open Apple Configurator 2 the screen will look like this.
Once your Mac is booted to DFU mode, you will see this screen on Apple Configurator 2. You are now ready for the next step.
11. Download macOS ISPW file (Optional)
Apple Configurator 2 version 2.13.2 will automatically download needed IPSW file just like it can for iOS. Let’s say that you want to download the IPSW so you can restore multiple times for testing, you can get it from my database below.
Once you’ve downloaded the macOS IPSW file, you are ready for Restore.
12. Begin Apple Silicon macOS Revive / Restore
1. Revive Option
The revive option will ONLY reinstall macOS Recovery. Go to step 2 for Restore.
You are now ready to restore either macOS Recovery with revive by Clicking Actions > Advanced > Revive Device.
Revive will reinstall macOS Recovery on your Apple Silicon Mac. This option retains user data.
2. Restore Option.
Restore will Reinstall macOS Recovery, ERASE your SSD hard drive and reinstall macOS.
You will now see a warning message. Do you want restore “MacBook Pro” to it’s Factory settings and latest firmware version?
Click the Restore Button to begin. Step one will download the latest macOS IPSW Firmware file directly from Apple.
You can also drag the macOS IPSW File over to the DFU icon to begin the restore.
After dragging the macOS 11 IPSW File over to the DFU logo you will get this pop up. You can select Restore to erase your drive and reinstall macOS. The process will only take about 15 minutes.
Step 2. Unzipping macOS
Step 3. Installing macOS
13. Finishing Up
If you would like to see more information you can click View and see a new activity window.
The entire process will only take a while. Most of the time is spent downloading the huge 13GB macOS Big Sur IPSW File. This is why it’s nice to keep the IPSW on an external hard drive or something. When you drag the IPSW File over to Apple Configuator 2, the restore will be super quick! Normally it only takes about 10 min!
When complete the Mac will automatically Boot up.
14. Can I Downgrade from an older version of macOS via IPSW Files?
The answer is YES, follow the link below for an explanation.
But only if the IPSW file is still signed by Apple. If Apple stops signing the IPSW file you will need to change the Boot Security to allow this. (Keep in mind Apple has not stopped signing any macOS installers yet, so we will see.)
15. Thanks
Hat tip goes out to macrumors forum user Nrwrit3r for the macOS Recovery menu workaround for older firmware!
NOTE 11/17/20! UNTIL I’M ABLE TO GATHER APPLE SILICON DATA I WILL LEAVE THE T2 BRIDGEOS TROUBLESHOOTING SECTION HERE.
I can’t get my Mac to boot into DFU mode. This is the toughest part of the whole process as I mentioned above. Keep trying the steps I listed above. Sometimes it takes multiple attempts to get his to work.
You can use System Information to see if the USB-C port lists your Mac in DFU Mode.
BridgeOS Restore Error 79- The OS Cannot be restored on this device. The Operation couldn’t be completed. (AMRestoreErrorDomain error 79 – Failed to handle message type StatusMsg) [AMRestoreErrorDomain – 0x4F (79)] – If you get this error it means that the BridgeOS update has failed and is unable to complete. The system will be unable to boot. When powered on the screen will be black. The Mac will have to be brought to an Apple Store for Service.
BridgeOS Restore Error 10 – The BridgeOS Restore failed! This is most likely because the host Mac was 1 or 2 OS Versions behind the Target Mac. The Host and Target Mac need to be on the same OS Version.
If your Target Mac is on 10.15, then your Host Mac needs to be on 10.15.
The OS Cannot be restored on this device.
The operation couldn’t be completed. (AMRestoreErrorDomain error 10 – Failed to handle message type StatusMsg) [AMRestoreErrorDomain – 0xA (10)]
Host Mac and Target Mac Disconnected during restore. – Error 4005
The OS Cannot be restored on this device.
Gave up waiting for device to transition from RestoreOS state to BootedOS State. [com.apple.MobileDevice.MobileRestore – 0xFA5 (4005)]
This error will come up when the restore process has been interrupted.
Or, you might get this using Apple Configurator 2 version 2.12.1, as the process never seems to complete properly. If the Target Mac awakes to the login window the process is complete even though the progress bar is at 100%. After unplugging the USB-C cable you will get the error above.
Apple Configurator 2 Reports RECOVERY instead of DFU Status.
If you see RECOVERY this means that BridgeOS is unable to boot and is the default status when you power on the Mac.
Failed BridgeOS Restore due to OS Version Mismatch! The Target Mac is a previous OS i.e 10.14 trying to restore a 10.15 Mac, the update will fail with an Error 10
If the Mac already failed the Upgrade, it could already be in this status. If so, you can attempt a BridgeOS restore.
Configurator could not perform the requested action. Apple Controller devices do not support this action.
This means that you selected Actions > Update, which is not supported. You need to select Actions > Advanced > Revive Device
Apple Configurator 2 BridgeOS Firmware Download Location.
Thanks MrMacintosh Reader Max C for letting me know the location of the BridgeOS Firmware files.
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.
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.
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!
The video above shows you how to factory restore / erase your Apple Silicon Mac and reinstall macOS.
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
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.
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.
I’ve also written an article that goes over the entire new DFU + Apple Configurator 2 Apple Silicon Restore process below.
6. Apple Silicon Security Policy
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 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.
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.
How to download Apple Silicon M1 macOS IPSW Restore Files. You can use them with Apple Configurator 2 and a 2nd Mac for quick restores.
UPDATED: 12/11/24
With the introduction of the new Apple Silicon M1 Mac, you can now reinstall macOS with Apple Configurator 2 and IPSW files just like iOS! This page is a database of all macOS IPSW Files. The macOS ISPW firmware files database will be updated when new updates are released.
Table of Contents
1.macOS Sequoia Final IPSW Firmware files
2. macOS Sonoma Final IPSW Firmware files
3. macOS Ventura Final IPSW Firmware files
4. macOS Monterey Final IPSW Firmware Files
5. macOS Big Sur Final IPSW Firmware Files
6. macOS Sequoia Beta IPSW Firmware files
7. macOS Sonoma Beta IPSW Firmware files
8. macOS Ventura Beta IPSW Firmware Files
9. macOS Monterey Beta IPSW Firmware Files
10. macOS Big Sur Beta IPSW Firmware Files
All download links are directly from Apple’s SUS Server.
For more information on how to reinstall macOS on your Apple Silicon Mac, I’ve written an article that goes over everything you need to know!
Apple said the first Apple Silicon Mac will launch before the end of 2020. The launch date is quickly approaching, now is the time to get up to speed! I will be following my “Everything you need to know” format from my previous articles.
This article will be updated as new Apple Siliconinformation comes in.
The feedback that I’ve received from these has been really great. The big takeaway is that everyone really likes how all the information is all in one place. You are not wasting time looking for that one article, command or link.
NOTE: Everything in this article is public knowledge from Apple. Once the first Apple Silicon Mac ships, I will post more in depth articles.
Apple Silicon changes the way in which we enter recovery on the Mac. In the past, we had to remember multiple keyboard commands. On Apple Silicon, all you need to do is hold down the power button. In a few seconds, you will see the new Apple Silicon Startup Manager.
7. How to use the new start manager on Apple Silicon
To enter Apple Silicon Startup manager follow these steps.
1. Hold down the power button
2. You will see the message “Continue holding for startup options”
3. The next message will say “Loading Startup Options…”
4. You will now see the new Apple Silicon Startup Manager.
The startup manager will show you the main boot disk (Macintosh HD) Boot icon and Recovery Options. Click “Options” to boot into macOS Recovery.
8. Internet Recovery is dead on Apple Silicon
Have you had trouble booting into Internet Recovery in the past? You are not alone. Now with Apple Silicon, Internet recovery is officially retired. It will still remain for Intel based Macs. For Apple Silicon we now have 3 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 System Restore via DFU mode + Apple Configurator 2.
9. Apple Silicon macOS Recovery
Apple Silicon macOS Recovery is almost exactly the same as it is on Intel Based Macs. The only difference is Security Policy options was moved from the Menu bar to the “Startup Disk”.
10. 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.
11. Both macOS Recovery and System Recovery are not available?
The blinking folder icon is now retired. If the Mac is not bootable, you will now see an old friend.
12. 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!
You can build out a USB Installer of macOS Big Sur and boot your Apple Silicon Mac to it. The big difference that ONLY the installer is available for a reinstall of the OS. You can NOT erase the drive in this mode.
13. 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.
This will help with rapid deployment in lab / school situations.
14. Apple Silicon Security Policy
We know that an Apple Silicon Mac will 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 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.
15. 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.
16. Can I downgrade macOS on Apple Silicon?
Yes! But only with your Apple Silicon Security Policy set to “Reduced Security”.
17. How to use SMB Mac Sharing Mode (Replaces Target Disk Mode – TDM)
Target Disk Mode has been retired on Apple Silicon. It was replaced with Apple Silicon Mac Sharing Mode.
Boot to macOS recovery and then select “Mac Sharing Mode” you will be able to transfer data over USB-C cable. You will need to authenticate with a SecureToken User that is on the host Mac.
18. Apple Mac Mini Developer Transition Kit (DTK)
New Mac Developer Transition Kit with Apple Silicon, a comprehensive set of resources, and one-on-one technical support, you’ll have everything you need to get your Universal apps ready before Apple Silicon Macs become available to customers.– developer.apple.com/programs/universal/
Universal App Quick Start Program – Get your Universal apps ready. The Universal App Quick Start Program includes all the tools, resources, and support you need to build, test, and optimize your next-generation Universal apps for macOS Big Sur. – developer.apple.com/programs/universal/apply/
5. What’s New for Enterprise and Education WWDC 2020 June 2020 (v1.0) (AppleSeed Account Required)– appleseed.apple.com
6. AppleSeed – macOS 11.0 Big Sur Beta Release Notes(AppleSeed Account Required) – appleseed.apple.com
23. WWDC20 Video Links
Port your Mac app to Apple Silicon – Your porting questions, answered: Learn how to recompile your macOS app for Apple Silicon Macs and build universal apps that launch faster, have better performance, and support the future of the platform. We’ll show you how Xcode makes it simple to build a universal macOS binary.developer.apple.com/videos/play/wwdc2020/10214/
What’s new in managing Apple devices. – iOS, macOS, tvOS We’ve made significant strides in bringing crucial device management features to macOS. Discover how these features can help you manage your all your devices using the same tools and technologies. Get details on changes coming this year and how they will impact your deployment workflows– developer.apple.com/videos/play/wwdc2020/10639/
iPad and iPhone apps on Apple Silicon Macs. – Apple Silicon Macs can run many iPad and iPhone apps as-is, and these apps will be made available to users on the Mac through the Mac App Store. Discover how iPad and iPhone apps run on Apple Silicon Macs, and the factors that make your apps come across better.– developer.apple.com/videos/play/wwdc2020/10114/
Explore the new system architecture of Apple Silicon Macs – Discover how Macs with Apple Silicon will deliver modern advantages using Apple’s System-on-Chip (SoC) architecture. Leveraging a unified memory architecture for CPU and GPU tasks, Mac apps will see amazing performance benefits. developer.apple.com/videos/play/wwdc2020/10686/
24. MacAdmin Blog Links
This list is specifically for MacAdmins. This will be an ongoing list of articles and posts that will help you learn the latest 11.0 changes.
Using Apple Configurator, you can now downgrade T2 BridgeOS Beta to a Production version of BridgeOS.
Downgrading the version of your T2 BridgeOS has never been possible. Developers and customers could only get a NEWER version of BridgeOS when updating or upgrading macOS. The ability to downgrade BridgeOS on a T2 Mac was simply not possible. This new change to Apple Configurator 2 most likely happened between version 2.12 – 2.12.1.
Table of Contents
1. Why would you want to downgrade from a beta version of BridgeOS?
2. Can you Downgrade to a Lower Production version of BridgeOS?
3. Problems Running Catalina with a Big Sur Beta BridgeOS Version.
4. Closer look at BridgeOS versioning
5. The Big Sur installer is now using DeviceIDs compatibility checks.
6. BridgeOSUpdateCustomer updater
7. How to Downgrade a Beta Version of BridgeOS to a Production Version.
8. The Revive Option (for science)
9. Final Notes
1. Why would you want to downgrade from a beta version of BridgeOS?
Let’s say that you installed Big Sur Beta 6, and are now having a ton of problems. You probably want to downgrade to Catalina so you can work again. The only problem is, you are still on Big Sur Beta 6 BridgeOS version 18.16.12370. Keep in mind, your Mac SHOULD still work fine with this version. An example of this is if you have Catalina 10.15.6 installed on your Mac, your BridgeOS version is 17.16.16610. Let’s say that you need to test something on version 10.15.3. After installing Catalina 10.15.3, your BridgeOS version will NOT be downgraded to the period correct version of 17.16.13050. It will run just fine on the 10.15.6 version of 17.16.16610 BridgeOS. The same is the case if you have a Big Sur Beta version of BridgeOS and you downgrade to Catalina.
2. Can you Downgrade to a Lower Production version of BridgeOS?
If you are running macOS Beta, then you can use Apple Configurator 2 to downgrade your T2 BridgeOS to a final or production version of BridgeOS.
What about if you are running a production version of macOS? You can downgrade BridgeOS with Apple Configurator 2, but only for 1 week after a new macOS software update. Apple will unsign the previous version of BridgeOS along with previous iOS updates.
3. Problems Running Catalina with a Big Sur Beta BridgeOS Version.
Let’s say after you downgraded from Big Sur Beta to Catalina 10.15.6, you are now having problems. You might start to see weird issues or crashes? Normally you would have to wait until the next beta or the production version of Big Sur to get a stable version of BridgeOS on your Mac.
Looking at the xml file, I need to find my 2019 16″ MacBook Pro. Regular Model Identifiers or BoardIDs are not used here. You need to find the iBridge ProductID. Below is a snippet of the above .xml file. Below the version of BridgeOS = 17P6610
5. The Big Sur installer is now using DeviceIDs compatibility checks.
A change to the macOS Installer Beta was noticed by @grahampugh. He noticed that the new Big Sur installer now looks at the Mac DeviceID for T2 Systems and BoardID for older 2017 and below Macs.
6. BridgeOSUpdateCustomer updater
Now that we have the DeviceID, how do we know which version of BridgeOS is compatible for this model? The xml file gives us a clue BuildVersion 17P6610. I am used to keeping track of the BridgeOS Boot Rom version which is listed like this 17.16.16065.
The BuildVersion/BuildNumber is located inside the BridgeOSUpdateCustomer > BridgeOSUpdateCustomer.pkg > BuildManifest.plist.
BuildIdentities
ApBoardID 0x3E ApChipID 0x8012 ApSecurityDomain 0x01 Info
Apple Configurator 2 offers two options to Reinstall/Downgrade BridgeOS. Only the Restore option will help you downgrade and stay on the Catalina specific version.
Restore = ERASES YOUR HARD DRIVE + Downgrade BridgeOS
If you want to downgrade to macOS Catalina and a Catalina version of BridgeOS, the fastest way is to use the Restore option. Once the restore is complete, you will be on a the Catalina Production Version of BridgeOS and will have empty hard drive. You can now use Internet Recovery to reinstall macOS Catalina.
What happens if you chose the Revive option?
8. The Revive Option (for science)
As noted above, you have no real reason to use this option. But for science, what would happen? If you are on Big Sur Beta want to downgrade T2 BridgeOS Beta using the Revive option, you will leave your Mac in a non bootable state. This is because you are now running a BridgeOS version that is OLDER than the required Big Sur Beta BridgeOS. The good news is, your T2 Mac is smart enough to repair itself! As soon as the revive option finishes, your Mac will boot to a flashing folder alert or the Internet Recovery boot menu. If it boots to the flashing folder, just boot to Command Option R or Command R and you will get the menu below.
Connect to the internet and let it continue. You will be brought to a message that says,
A software update is required to use this startup disk.
Click Update and your mac will download the correct build of Big Sur Beta BridgeOS.
Once complete, the Mac will boot back to Big Sur. The only way to avoid this would be to boot the Mac to Target Disk Mode so you could erase the drive and reinstall Catalina. That’s why if you want to have BridgeOS and Catalina on the same version the Apple Configurator RESTORE option is the way to go. Just make sure to backup everything before you start as all data will be lost.
9. Final Notes
It should be pretty rare that you should ever need to downgrade BridgeOS from a Beta version. Keep in mind this will ONLY work for beta versions. As I noted above you can’t downgrade from a 10.15.6 version of BridgeOS to say a 10.15.3 version. With that said I would love to be able to downgrade to a previous version. If it’s your job to test OS Updates, once you update one test T2 Mac it’s done. It will not perform the BridgeOS update again until the next update. I really like that Apple let’s us downgrade from a beta version of BridgeOS, the more ways for customers to fix their devices the better! A big hat tip goes out to Mr. Macintosh reader thomas089 for first testing this and commenting in my main article!