I'm new to the ECU (or chip) tune concept, and I try to understand what is going on there.
I understand the concept and the goal, but I'm having difficulties to understand what is actually going on there.
From what I understand the process for tuning is:
- Download ECU firmware from the car.
- Modify some constant values (in the map).
- Write the modified ECU back to the car.
However, I can't understand what is the format of the downloaded ECU - is it just a regular firmware? I found many websites like this which offer to download ECU files, but I couldn't recognize the format - it doesn't look to me like any firmware, and I couldn't identify any CPU architecture on all the files I tried. In addition, the size of the files is almost always 512KB, 1024KB or 2048KB which is not very typical to firmware.
When downloading files from those sites I see that many of them referenced as ori (original?), some of them as map and some of them as bdm. (Needless to say, there is not much information about the formats in the sites..). What do these types mean?
If I want to reverse engineer the firmware of the ECU - are those the files that I should look at?