Apart from on IA64, UEFI was pretty invisible in the open source community up until the point where Microsoft announced their plans/requirements for mandating UEFI Secure Boot. While BIOS was outliving its usefulness on x86, even those hardware vendors that shifted to using UEFI "under the hood" provided BIOS emulation for backward compatibility.

This has now changed/is now changing. Some x86 systems are already shipping without legacy mode, and AArch64 (or arm64, depending on your water supply) servers will be shipping with UEFI firmware next year.

So, since the community cannot ignore UEFI, this presentation hopes to clarify the various aspects of UEFI - helping everyone hate the bit they should be hating for the right reasons, rather than bundling it all together :)

This is an updated/evolved version of the talk that was given at the 2013 UK mini Debconf.