CHDK is only for a narrow range of Canon P&S Cameras... Some very smart person looked at a firmware upgrade for one of the Canon P&S cameras, reverse engineered the code, and then figured out how to write new software (CHDK) for Canon's internal firmware and hardware.
That person (or small group), made their first efforts "Open Source" and now quite a few people have grabbed hold of that and are now collaboratively improving the base code and adding (called porting) more Canon P&S models by the month.
There is a small thread in the CHDK forum where some folks are trying to do the same for the Canon DSLRs now--but they still have quite a bit of work ahead.
This same effort may be possible for brands/models of cameras--but it is a new project that would have to start from ground zero and probably would not use any code from CHDK.
And this is beyond the scope of the CHDK forum and would not be supported here (guessing with that last statement--I am not anybody special here--just trying to help answer questions in "payment" for the great work done by the others here).
-Bill
