IFI_Loader protocol?

[Shinigami2057]

Hi all, I have a few questions for the programmers from AdamBots or anyone else who knows anything about the IFI_Loader protocol, especially in regards to the ifipictools program. I'm sorry this post is so long, but

I am in the process of writing a portable program loader specifically for the FRC. I've written the Intel HEX file reader and I know how I'm going to go about working with input and output from the serial port, but I have really no idea what I'm sending to the FRC's program port. I was originally just going to extend ifipictools, since it has an open license, but upon looking at the code, I have absolutely no idea what's going on, as nothing in the code lends to figuring what exactly it DOES.


Basically, all I really get out of it (based on the variable names in the program, since there are no useful comments) is that to load the program, you have to:
1) Send version information to the PIC.
2) Send a "base read" command to the PIC.
3) Send two commands that erase whatever is currently in flash program memory.
4) "Splice" blocks of memory read from the HEX file into a command that tells the PIC to write that block to whatever address.
5) Close and reopen the connection to the controller
6) Send the reset command to the controller.
And in between reads and writes to /dev/sttywhatever you need to wait a few milliseconds to let the FRC write to the user PIC18 before sending more data.

Could anyone involved in the project please help me understand what exactly is going on in that code sequence? Did you get help from IFI or did you just try to pick apart the data going between the FRC and IFI_Loader by monitoring the serial port? Any help would be GREATLY appreciated.

All the work I'm doing on this project will be released under the GPL and will hopefully be cross-platform, so that any team can use our program loader, whether they're using Linux, Solaris, OSX, Windows, or whatever. Attached is the latest version of ifi-pictools and what I've got for the HEX reader right now, which is mostly useless by itself.

Harry