Bootstrapping

• Recovery boot to a shell
• Steps in the boot process
• Userland

BIOS/UEFI

• Movement from old BIOS to UEFI

GRUB

• GRUB 1 versus GRUB 2
• Older: LILO still in some use

USERLAND

• Systemd
• Older init scripts

Reboots and shutdown

• Poweroff
• Shutdown (possibly very polite)
• Halt
• Reboot