On 08/10/17 12:47 PM, D. Hugh Redelmeier via talk wrote:

There are two ways of booting a PC.

- old-style Master Boot Record: the BIOS loads the first sector of the
  drive and then jumps to it, in 8086 mode.  Everything that happens
  from there depends on the contents of the disk, not the firmware.
  (Except that the BIOS supports 8086-mode calls into the BIOS
  routines.)

- new-style UEFI booting.  The firmware *does* understand the
  partitioning and certain filesystems, enabling it to load and run
  64-bit programs, and those programs can use the UEFI-defined
  routines provided by the firmware.  Those programs reside in an EFI
  System Partition

Most motherboards sold as components (as opposed to coming within a
computer) support both these days.

Slightly off-topic, Dave Taht pointed me to the NERF project
https://schd.ws/hosted_files/ossna2017/91/Linuxcon%202017%20NERF.pdf

It's purpose is to avoid attack vectors using EFI, the management engine and system management mode.

If you can boot from MBR, do.

--dave

-- 
David Collier-Brown,         | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
davecb@spamcop.net           |                      -- Mark Twain