Users of Canon's camcorders have asked for tools like chdk. There is some work happening on various models.
“There's an official firmware update available which updates version 126.96.36.199 to 188.8.131.52, and you...HF10/100 Firmware Analysis
“Is there yet or going to be a version of CHDK for the Canon FS100? It would make my day if there...CHDK for Canon FS100
“This HDV camcorder was released in January 2007, and has become a very popular tool for indie...HV20
“Canon has released an update to version 184.108.40.206. Where and how to get the firmware and a serial...HV30 Firmware Analysis
“HD camcorder based on the HV20, the HV30 offers some physical body improvements as well as a new...HV30