GRUB is a portable, powerful bootloader. This version of GRUB is based on a
 cleaner design than its predecessors, and provides the following new features:
 .
  - Scripting in grub.cfg using BASH-like syntax.
  - Support for modern partition maps such as GPT.
  - Modular generation of grub.cfg via update-grub. Packages providing GRUB
    add-ons can plug in their own script rules and trigger updates by invoking
    update-grub.
 .
 This package contains GRUB modules that have been built for use with the
 EFI-AMD64 architecture, as used by Intel Macs (unless a BIOS interface has
 been activated). It can be installed in parallel with other flavours, but
 will not automatically install GRUB as the active boot loader nor
 automatically update grub.cfg on upgrade unless grub-efi-amd64 is also
 installed.