In the German forum we currently discuss the addition of an ATmega169 based board. I'm just wondering where to find documentation about the related files, what to change etc.
Some specific questions:
How does the compiler find the files related to a controller, related to a board?
How are controllers and variations handled? (The 169 differs from the 169AP...).
Where are the interrupt vectors defined (array, names)?
Where are the register names/addresses defined?
Value of LED_BUILTIN for no such LED?
And finally where to send the changes and added files, for addition to the IDE distribution?