As simple as possible! Thank you! I'll write it on wiki;)
Ok, but should there be a PS.FI2 file? I didn't get it. I copied this file from autobuild and now I'm not sure wheter I have native functions enabled or not...
The FI2 is only generated if you have the FI2 keys configured.
PS.FI2 and DISKBOOT.BIN are two complete, independent CHDK binaries. You use one or the other, and and whichever one you aren't using has no effect on CHDK functionality.
PS.FI2 is used when you load manually with "firmware update"
DISKBOOT.BIN is used when you load with a bootable SD card.