BridgeOS

BridgeOS is an operating system developed by Apple Inc. for use in its T2 security chip, which is embedded in various Apple devices. The operating system is based on watchOS, and it manages many of the core and security functions of Apple's modern hardware.

Overview

BridgeOS is a derivative of watchOS, which itself is a version of iOS designed for Apple's Apple Watch. The operating system is designed to run on Apple's custom T2 security chip, which is a System on a Chip (SoC) that integrates several components, including the Secure Enclave and an ARM-based processor.

The T2 chip, and by extension BridgeOS, is responsible for a variety of functions on Apple devices. These include the secure boot process, encryption for the built-in SSD, and the processing of the image signal from the FaceTime camera. It also handles audio processing and controls the "Hey Siri" functionality.

Security

One of the primary roles of BridgeOS is to provide security features for Apple devices. The T2 chip's Secure Enclave, which runs BridgeOS, is a hardware-based key manager that's isolated from the main processor to provide an extra layer of security. It's used for secure boot, SSD encryption, and Touch ID data.

The secure boot feature ensures that only trusted software loads at startup. It uses cryptographic verification to check the integrity of the operating system and the boot loader. If the checks fail, the system enters recovery mode.

Compatibility

BridgeOS is compatible with several Apple devices that include the T2 chip. These devices include certain models of the MacBook Pro, MacBook Air, Mac Mini, and iMac Pro. The T2 chip, and therefore BridgeOS, is not user-accessible, and its firmware can only be updated through macOS.

See also

• Apple-designed processors
• Macintosh operating systems
• Secure boot