I've created a custom board that can be programmed using any one of several programmers defined in programmers.txt. I would like the user to be able to choose which programmer to use via the "Tools->Programmer" menu options.
I tried using {protocol} and {upload.protocol} in platform.txt to pass the programmer to the upload tool, but neither seem to be defined when the Upload button is used to initiate the upload (they are defined if Upload using programmer is selected from the menu).