Parameter Passing

This chapter, explains how the avr-gcc compiler suite uses the available registers in the ATmega328P and the precautions that your Assembly code must take if it uses any of the registers itself. We also look at the different ways in which parameters are passed from C\(++\) to your Assembly code; as well as an in depth discussion of the stack frame pointer, as documented in the avr-gcc documentation; and discover exactly how useful it is, or is not, in our Assembly functions.