Replying to question sent in PM.
i have successfuly disassembled the firmware dump but i dont know how to search for the right names for the functions.
Generally speaking, you won't have names. The exception is "event procedures" which are function that are exported to the firmwares own scripting system. CHDK uses some of these, and you can sometimes also use them as landmarks to find other code. To find eventprocs, you find the string name, and then find references to the name that are also associated with a reference to a code pointer. Often there are tables in the firmware of a pointer to the name and a pointer to the function.
For stuff that doesn't have names, you have to find other landmarks in the code. These can be other strings, like log messages or task names or calls to functions that you've already identified by other means.
Since srsa has created a working digic 6 port, your best approach is probably to work form that. First you have to understand the general organization and the startup process (this begins in the cameras loader subdirectory). After that, to find specific functions you can look at the disassembly of his firmware and then try to find the equivalents in your firmware.
This is going to require a fair bit of reverse engineering knowledge, there is no way around it. You can teach yourself what you need to know, but it will not be an easy project. You will definitely need to learn thumb2 assembler.