Welcome to Chucky

Firmware updates made child's play!

Welcome to the chucky project. The goal of the project is to make firmware updates of small devices faster by the idea that the update will probably contain mostly the same content as the previous version. The idea for this was taken from the casync program. casync might not be fit for microcontrollers where chucky is intended for microcontrollers!

Structure

• chucky is the program that slices the firmware image in seperate chunks
• tiffany is an implementation of the update algorithm in C which can be run on a microcontroller.

Usage

To compare two firmware files, use the compare command like this:

python chucky.py compare ../demos/pybv10-20170611-v1.9.1.dfu ../demos/pybv10-20170823-v1.9.2.dfu

This example command compares two micropython releases from https://micropython.org/download/

Build status

Ideas

• hash calculation on target is not required, since we keep the table with old hashes
• TBD: use leb128 to store integers to save space?

Credits

• The whole idea began when attending the FOSDEM 2018 talk of Lennart Poettering: https://www.youtube.com/watch?v=Hfmpaymmpa8

  https://fosdem.org/2018/schedule/event/distributing_os_images_with_casync/