[syslinux] why is "tsize" required?

[Scott Bertilson]

  Perhaps a stupid question, but I've read through the
changelog and the e-mail archive and can find no answer.
I'm wondering why "tsize" is a necessity.  Seems like
the TFTP protocol correctly handles EOF.  Does the code
need to know in advance how large the file is going to
be?
  If it just happens to have been written this way,
would you be open to a change which eliminates the
requirement?
				Thanks, Scott