Thanks rcp for the detailed response. Meanwhile, I changed to "nano" and the code was reduced to 30.4 kB. But I can't identify, in the properties, as a Debug build. For example, there's no something like -DEBUG symbol in preprocessor.

Also, as you suggested, I've built a Release version based on Debug. But it seems to have the same properties as Debug and the same generated code size (just the name was changed to "Release"). Some additional suggestion?