Modify an example from Atmels application note 2565 to a make/gcc based toolchain.
Atmels application note AN_2565 describes the usage of the two wire interface (TWI) to implement the function of a i²c slave device, including some basic example code. This examples have suitable configurations for the IDEs Atmel Studio and IAR.
To use it as a starting point for a project some work has to be done for building with a linux make/gcc toolchain.
The code is taken from the subdirectory Standard/Atmel Studio/TWI_Slave and inititally imported as it is.