Unified Extensible Firmware Interface

Is a set of specification & Software platform that is used to boot and interface with an Operating System

Secure Boot

• Is a method to check whether a bootloader is digitally signed.
• Boot Order Lock also lock book order and shim selection

USB Key preparation

• In Rufus, prepare a non-bootable MBR FAT32 key
• Then copy the required files, for example from Clonezilla

UEFI Shell

• Works similarly to a bash shell
• The bootloader is searching for /EFI/BOOT/bootx64.efi by default ^333cb0

Commands

• map to show the mapping table
• cd /EFI/BOOT/ to browse to path
• bcfg boot add 1 bootx64.efi "OSname" to add an entry
  • 1 being the priority

Recover from a bad boot

• You are greeted with the UEFI Shell, so try to find the loader:
• The mapping table will give you all devices that EFI see, like FS0: or HD0b:
• Browse to the bootloader
  • FS0:
  • cd EFI\debian
  • grubx64.efi