Comment 37 for bug 1466150

@Georg Sauthoff wrote:

> Can you name _one_ UEFI implementation that actually does write to an ESP?

Offhand, I don't know of an EFI that will write to the ESP automatically; HOWEVER, there are cases when it can happen because of user actions and/or EFI applications' operation. For instance:

* The EFI shell includes multiple commands that can write to the
  ESP when the user executes them -- file copies, file renames,
  a built-in text editor, etc.
* The rEFInd boot manager includes options to store rEFInd-specific
  variables on the ESP, as well as to create screen shots. The older
  rEFIt can also create screen shots.
* There's a whole Python implementation for EFI, so in theory,
  users could run Python scripts that write to the EFI.

Assuming that the user knows enough to not do these things seems like an unwise assumption, IMHO.