The first article in the Linux Foundationals series. It traces a Fedora system from the UEFI handoff through shim and Secure Boot, MOK enrollment with mokutil, GRUB2 and Boot Loader Specification entries, the dracut initramfs and switch_root, all the way to systemd as PID 1. Then it covers units, dependencies versus ordering, targets, and how to measure and fix a slow boot with systemd-analyze.