You can now upgrade or downgrade BridgeOS with an IPSW file and Apple Configurator 2!
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 T2 BridgeOS with an IPSW file and Apple Configurator 2 (for up to one week after the release of a new macOS update)
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.
Dragging BridgeOS IPSW file over to Apple Configurator 2
The Restore/Revive menu after dragging the BridgeOS IPSW file over to Apple Configurator 2.
Restore or Revive menu for BridgeOS
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.
This is the message that you get when you attempt to install an unsigned version of BridgeOS.
macOS Big Sur 11.4 (20F71) is now available for all users!
UPDATED 05/27/21
Apple just dropped the new macOS Big Sur 11.4 Update (on a Monday???). The 11.4 update was released only a month after 11.3 Let’s jump in and find out what’s new!
The 11.4 update also patches the screen shot vulnerability CVE-2021-30713.
The detection team noted that once installed on the victim’s system, XCSSET was using this bypass specifically for the purpose of taking screenshots of the user’s desktop without requiring additional permissions.
jamf.com
Jamf security researchers found the vulnerability and detailed it in the article below.
The macOS Big Sur 11.3 (20E232) update is now available for all users!
UPDATED 04/29/21
Apple just released macOS Big Sur 11.3 just one week after Apple’s “Spring Loaded” event. This is the one of the longest beta cycles that we’ve seen. The release had 8 beta and one Release Candidate Update. We have a brand new 24″ iMac with 7 different colors! The previous 11.2 update was released a over 2 and a half months ago.
Apple’s “Spring Loaded” Event Notes:
iMac!!! 24″
New iPad Pro with M1 Processor & ThunderBolt
New Magic keyboard with Touch ID
AirTags introduced
Apple TV 4k with A12 & Remote
11.3 Big Sur & Safari version 14.1 (one week later)
The new Let’s jump in and find out what’s new in the macOS Big Sur 11.3 Update!
macOS Big Sur 11.3 Patch Notes Summary
53 – Security Fixes
29 – New Features
13 – Enterprise Changes/Fixes
7 – Resolved Issues
Mr. Macintosh macOS Big Sur 11.3 quick 5 min video on all the new features.
My macOS Big Sur 11.3 everything new in 5 min video! Stay tuned to my normal DEEP DIVE video!
My 2nd video that is more of a discussion and deep dive into the 11.3 update.
Mr. Macintosh 11.3 Update Deep Dive Video.
Table of Contents
1. Apple Links
2. Mr. Macintosh articles of interest for Apple Silicon & macOS Big Sur
3. Apple Articles of interest related to the macOS Big Sur 11.3 Update
4. Undocumented macOS Big SUr 11.3 Update changes & fixes
5. Previous Big Sur 11 Beta and Final Releases
6. macOS Big Sur 11 Standalone Pkg downloads no longer available.
7. macOS Big Sur 11.3 Full Installer.app
8. macOS Big Sur Update sizes for Intel and M1
9. Apple Silicon M1 Firmware Update
10. Intel T2 BridgeOS Update
11. Apple Silicon IPSW Restore file Update
12. Safari 14.1 Update
13. What’s new for enterprise in macOS Big Sur 11.3
14. Security Content of macOS Big Sur 11.3
15. macOS Big Sur 11.3 (20E232) Release Notes / Patch Notes / Changes
Click “Continue Reading” for the rest of the article.
How to remove the firmware password on 2011-2020 Macs + New way for 2018-2020 T2 Macs!
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?
The macOS Big Sur 11.2 (20D64) update is now available for all users!
MacOS Big Sur 11.2 was released on February 1st, 2021. The 11.2 update is the 2nd major update for Big Sur. This release had 5 beta updates, which is a record for small point releases. The 11.2 update was released one week behind the iOS 14.4 update.
UPDATE: 02/02
This version is the same BuildVersion as 11.2 Beta RC3 = (20D64)
If you installed macOS Big Sur 11.2 RC 3 (20D64) you have the production version of macOS and you do not need to update.
Full installer released – 12.22GB
Waiting to see if CVE-2021-3156 sudo buffer overflow sudo privilege escalation affects the macOS version of sudo 1.8.31. (11.2 still includes sudo 1.8.31)
NOTE for the next version of Xcode – “Xcode 12.5 Beta requires a Mac running macOS Big Sur 11 or later.”
SoftRAID – macOS Big Sur 11.2 update does not allow the SoftRAID driver to load
Safari 14.0.3 was just released at 5:30 PM CST for Catalina and Mojave (it’s included in the 11.2 update)
macOS Big Sur 11.2 Patch Notes Summary
0 – New Features
5 – Resolved Issues
6 – Enterprise Changes
Click “Continue Reading” for the rest of the article.
Security Updates 2020-001 for Catalina & 2020-007 Mojave
Security Updates 2020-001 for macOS Catalina (19H114) & 2020-007 Mojave (18G7016) & Safari 14.0.2 are now Available.
Apple has released Security Updates 2020-001 (Catalina) and 2020-007 (Mojave). MacOS High Sierra is now officially unsupported by Apple. The 2020-006 Security Update was High Sierra’s final update. Mojave has taken its place as the 3rd supported version of macOS behind Catalina.
Since this security update is Catalina’s first it was named 2020-001. Mojave has had 7 Security Updates so the version is 2020-007. Next year they will both be named 2021-001.
Mr.Macintosh 2020-001, 2020-007 & Safari 14.0.2 Security Update video
Mojave however still does! The 2020-007 security update creates a snapshot and does NOT purge previous snapshots.
I really wish Apple could get this feature working again.
The Safari 14.0.1 upload issue is not fixed in 14.0.2.
A simple example of this is using Gmail in Safari. If you update to Safari 14.0.1 or 14.0.2 you will be unable to attach anything to an email The only work around right now is to use Chrome or Firefox.
New workaround = drag and drop the file into the window.
Install Process Fixed!
With the release of 2020-006, Apple has changed things up. In the past you could have the base version of Mojave, 18G103 for example and the latest security update would show as available and you could update right to it. With 2020-006 you will need to be on 2020-005 first before you can update to 2020-006! This is a huge pain if you have systems that are behind in build versions.
Example.
If you have a fresh build of macOS Mojave 10.14.6 (18G103) and you want to get to 2020-006.
1. Install Security Update 2020-005 first.
2. After installing 2020-005, you will now see 2020-006 available for instal in software update.
With the release of the new 2020-001 and 2020-007 Security Updates, Apple now lets you jump straight to the latest update.
Updated Fixed Example
If you have a fresh build of macOS Mojave 10.14.6 (18G103) and you want to get to 2020-007.
Install 2020-007 = Done
Testing the Security Update Install Process
After all the problems of the 2020-005 Security Update for Mojave caused, I wanted to again make sure everything was ok with 2020-001 & 2020-007. I’ve installed both the 2020-007 and Safari 14.0.2 updates and have not found any issues. You can safely install both of them together.
Click “Continue Reading” to read the rest of the article.
Today Apple released macOS Big Sur 11.1 (20C69) to the public.
MacOS Big Sur 11.1 was released on December 14th, 2020. The 11.1 update is the first major update for Big Sur. The release comes a few days after Big Sur 11.1 beta RC and is the same build number. Big Sur 11.1 also brings support for AirPods Max, Apple’s new over-ear headphones. New Features added to the following apps Apple TV, Apple News, App Store, iPhone Apps on M1 Macs, Photos and Safari.
UPDATE: 12/15 – 11:30AM
This version is the same BuildVersion as 11.1 Beta RC = (20C69)
softareupdate –fetch-full-installer is fixed! (Was broke in 11.0.1)
2013 & 2014 MacBook Pro 13″ Bricking issue looks to be fixed in 11.1! The BoardID for this model was added back to the full installer.
