Since replacing Open Firmware in 2006, EFI firmware has undergone major change. Now only installed as part of a macOS install or update, here’s its story.
firmware
Upgrading to Monterey is simple for the great majority of users. But what can you do if you can’t get it to install? Here are plenty of options.
Going from 11.0 to 11.6 required over 50 GB of updates for an M1 Mac. Has Monterey tamed the beast, and reduced them? And which Macs will be supported by macOS 13?
Once the kernel takes over from iBoot, there’s a lot of hardware to get running before the SSV can be properly validation, and kernel extensions loaded.
Sometimes known as iBoot1 and iBoot2, they start work with the LocalPolicy for the intended boot volume, validating its vital components.
Understanding each of the four stages in the Secure Booting of an M1 Mac. These are summarised in diagram available here.
There’s a fundamental difference in the way that Intel and M1 Macs store and load their ‘firmware’, which enables the M1 Mac to load and run difference versions of iBoot.
This article has now been extensively corrected and modified.
For those who want macOS updates promptly, SilentKnight can be a help. But don’t use it to download and install an update.
Improved reporting of firmware, Gatekeeper, and clearer documentation are the main improvements.
The Eclectic Light Company 