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by Jason Snell & Dan Moren

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By Jason Snell

Macs with Apple silicon will get new, refined boot and recovery mode

Note: This story has not been updated since 2020.

Doing unusual things at Mac startup has long required remembering keyboard shortcuts. Is it Command-Control-P-R or Command-Option-P-R that zaps the PRAM? Is that still even a thing? Is it Command-S for Recovery Mode—or wait, that’s Single User Mode, it’s Command-R for Recovery mode, Command-T for Target Disk Mode, Option to choose a startup disk.

With the advent of Macs running Apple-designed processors, things will get a whole lot simpler. As described Wednesday in the WWDC session Explore the New System Architecture of Apple Silicon Macs, these new Macs will only require you to remember a single button: Power. (On laptops, that’ll be the Touch ID button. On desktops, presumably it’s the physical power button.)

Holding down that button at startup will bring up an entirely new macOS Recovery options screen. From here you’ll be able to fix a broken Mac boot drive, alter security settings, share your Mac’s disk with another computer, choose a startup disk, and pretty much everything else you used to have to remember keyboard shortcuts to do.

Now that Apple is holding all the cards, the company has built a new boot process, based on iOS’s existing secure boot process, but modified to support those features that Mac users expect, such as different macOS boot drives, multiple versions of the operating system, and macOS Recovery itself.

On these new Macs, Target Disk Mode will be retired in favor of Mac Sharing Mode. Rather than turning your Mac into a disk, the new Mac Sharing Mode will turn your Mac into an SMB file server. As with most of the features of Mac Recovery, you’ll need to authenticate yourself before turning on Mac Sharing Mode.

These Macs will also have a little more granularity when it comes to boot security. Each startup volume can be set to a different security mode, either full security (which is the default) or reduced security. This means that external disks will be able to be booted from without downgrading security.

In reduced security mode, you can boot any supported version of macOS, even if Apple’s no longer signing it. And if an app or accessory you rely on uses a third-party kernel extension to enable functionality, you’ll need to use this mode.

For a while now, Macs have been able to recover from disasters by booting to the hidden System Recovery partition. When even that partition is gone, Intel Macs fall back to Internet Recovery. Macs with Apple-built processors will have access to different hidden area, System Recovery, which offers a very minimal version of macOS that will allow you to reinstall both macOS Recovery and macOS itself. (If System Recovery is also unavailable, it’ll be time to attach the Mac to another device running the Apple Configurator app to bring it back to life.)

Once the booting is complete, there’s also a new login window that’s more capable, because the system can fully boot before the user even presents their login credentials. It includes built-in support for smartcard authentication and supports VoiceOver as well.

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