Then you should get an extra menu option at the bottom of your menu (in Play mode only) that says Firm Update, and when you select that the CHDK should boot up. The other way is manual boot (also known as firm update) where your camera will start up with only the original Canon menus. One way is autoboot, where it will boot up automatically whenever you turn on the camera. There are two possible ways to use the CHDK on the camera. 5.1.2.1 Remove the Flags Using the Terminal.5.1 You may have issues with permissions.4.4 How to Copy Script Files Without Errors.3.4.1 What if nothing is available for my camera?.3 How to Install CHDK on a SD Card Using a Macintosh.1 A guide to installing and using CHDK with your Mac.