What is BridgeOS
BridgeOS is a special operating system that runs on auxiliary chip T1 or T2 in some MacBooks, iMacs and Mac mini (roughly 2016-2020).
This chip has its own ARM processor and a separate system that works next to macOS.
What BridgeOS is for:
- Managed by Mac security features - e.g. Touch ID, Secure Enclave, data encryption, access authentication.
- Provided by Secure Boot and macOS integrity check.
- Managed by built-in camera, microphone and sensors.
- Enables communication between the main macOS and the T2 chip.
Simply put:
➡️ BridgeOS is the “little system inside the Mac” that watches over security and hardware.
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How to update BridgeOS
BridgeOS is does not update independently –
is updated automatically with macOS.
Procedure:
- Open → System Settings → General → Software Update.
- If a new version of macOS is available, run the update.
- The installation also updates T2 chip firmware, and therefore BridgeOS.
Do not perform any manual installation of BridgeOS!
Manual interventions (e.g. via DFU mode) are only for service or firmware repair using Apple Configurator 2.
Restore BridgeOS (if the Mac won't start)
If a Mac with a T2 chip doesn't boot (black screen, flashing LED, non-functioning Touch ID), BridgeOS may be corrupted.
In this case, it is possible:
- use Apple Configurator 2 from another Mac,
- connect a problem Mac via USB-C,
- and make revive or restore firmware.
