Big Sur and Monterey allow kernel extensions with limitations, particularly on M1 models. Full details, including how to control them.
kernelcache
How the kernel relies on its extensions to make your Mac work, and has highest privilege for stability and security. How this must change for Apple Silicon.
Stepping through key points in the log as Mojave 10.14 starts up. Most of the key waypoints are similar to those in High Sierra.
Adds details of the sequence of screens displayed at each stage, to help diagnose boot problems.
Single-diagram summary of how a modern Mac starts up in macOS 10.12 or 10.13, from pressing the Power button to running the kernel.
How macOS gets to load a hefty kernel and over 300 extensions so quickly: it cheats with a pre-linked kernelcache. And why you don’t see extensions loading in the log.
The Eclectic Light Company 