In this section, we will see the macOS system initialization process, including all the stages, and what happens at each stage of this process. We will also look at a few other important processes, such as logging out, shutting down, and restarting.
The initialization stages can be distinguished as two larger processes, each with their own smaller stages:
- The primary system stages
- The user session stages
Let's take a look at the initialization stages in more detail, including what happens at each stage in terms of visual and audible cues (including colors, icons, and sounds).
Primary system initialization stages
There are four system initialization stages in macOS, and these occur in the following order:
- Power-on or BootROM firmware
- Booter
- Kernel
- System launchd
Let's take a look at each of these in turn.
Power-on or BootROM firmware
This is the power-on stage during which the system hardware is initialized by the BootROM firmware...
