Apple Firmware Engineer interview questions

One phone call with HR, one phone call with the group manager. The first day of interviews included two interviews back-to-back of an hour long each one. They first one mainly focused on technical questions and the second was balanced between technical questions and previous experience discussion. The first interviewer was really pleasant, the second one was just awful - he was not nice at all. He wasn't open for discussion, and cut me all through our discussions when I was explaining things.