Vincent has a new blog post, with some history of UEFI and recent security conference interactions, and includes a snippet of some old EFI code from Ken Reneris!
(I used to work with Ken. He is amazingly proficient coder. When he went on vacation to get married, we replaced his keyboard driver such that the ‘;’ key would replace the ‘:’ key randomly. (Back then drivers weren’t signed and a lot easier to replace.) His response was to rewire the person’s mouse so that it would work upside down/backwards.)