On Sat, Oct 7, 2017 at 3:46 PM, Didier Kryn <kryn@???> wrote:

>     Then maybe I misunderstood the reason for EFI.

UEFI is a huge step forward in pretty much all areas and makes booting
both simpler and more powerful.

Grub on BIOS basically works like this: the one MBR is read by BIOS
and executed (512 bytes!). That contains code to chain load some more
code (usually from a fixed set of sectors on disk!). That is phase 1
of the boot loader. That has enough smarts to find a hard-coded
partition and read phase 2 from there. Phase 2 will then load a ton of
modules and some configuration files and do the actual work.

With UEFI the firmware just loads a efi binary with everything:-) MUCH simpler.

UEFI has a couple more features:

* UEFI allows for better hardware support (graphical login at full
resolution, mouse support, RAID drivers, etc.)
* UEFI allows for more security with secure boot. E.g. my thinkpad
*only* boots things that I have signed with my key.
* UEFI allows for different OSes living next to each other peacefully,
without the constant fight over who writes the MBR and with that
defines the boot loader.

Best Regards,
Tobias