Modifying the CHDK Sources

Requirements

If you want to modify the existing CHDK sources to build your own version, you need:

• Knowledge of the programming language C. (online tutorials and resources)
• A simple text editor to modify the source code or an advanced texteditor with syntax highlighting (for example Notepad++) or a C development environment.
• The source code (How to get it).
• Instructions how to compile the CHDK, which can be found here: Linux, Windows and Mac OS X.
• A SVN-client may be useful if you want to participate in the CHDK development or if you want to keep your own version always up-to-date (see here).

Procedure

The procedure itself is pretty straightforward: Try to figure out what the source code does, apply modifications as you see fit, compile it and test it on your camera.

Don't be afraid to change anything! From a safety point of view you can modify any files. There is no code in the sources which allows to update (rewrite) the original firmware (read here). So, the worst thing which can happen is just that the new code wont work. If that happens, turn off the cam or remove the batteries, and everything should be fine again.

Source Guide

The Source Code on SVN Trak.

• trunk - This is probably the one you are using on your camera and which you want to modify. this is the MAIN CHDK tree
  • bin - Binaries. Normally empty. You will find your binaries here after compiling the source.
  • core - The core of the CHDK. If you like to add something or modify the existing functionality, this is probably the only folder you need to look into. (Maybe also 'lib' and 'include'.)
  • doc - Documentations. Not necessarily needed for compiling your own version.
  • fonts - Fonts. Not needed for compiling your own version.
  • include - Header files. Also see 'core'.
  • lib - Libraries: some math and standard C functions, uBASIC, fonts, other "separate" stuff. Also see 'core'.
  • loader - Initial code ran by camera. Sets up various things. No need to modify anything here (except perhaps if you want to port the CHDK onto a new camera model).
  • platform - Camera-/Firmware-dependent code. You only need to modify anything here if you want to add new references to functions of the original firmware.
  • platform/general - Camera-/Firmware-independent code. You only need to modify anything here if you want to add new references to functions of the original firmware.
  • script - Example scripts. Not needed for compiling your own version.
  • tools - Tools to make life easier :). You only need to modify anything here if you want to add new references to functions of the original firmware.

• branches - There are few branches in there worth mentioning:

Note: most of these branches are abandoned and discontinued now. Use the Trunk branch. Read more about it here.

• dataghost - DataGhost's experimental branch with LOTS of nice things he found out (mainly about the s5is) - see here
• grand - grAnds original branch
• juciphox - a quite new branch created by Jucifer and PhyrePhoX which then later was merged into the main CHDK
• old-trunk - well, the old trunk - before the merging of JuciPhoX
• vitalyb - backup of the original branch by the founder of CHDK - vitalyb

Links

• Adding support of a new camera
• List of Propertycases
• List of Params