Arm Systems Engineer interview questions

Since it was a campus placement, there was a lot of waiting between interviews as usual. I had to wait for 5 hours for my first interview. I had applied for SW role. 6 people from ARM came to take interviews on offline mode. Out of them, only 1 is in SW dept, others in HW. The rest of the SW interviews were taken online by people in ARM office. My interview was somehow taken by a HW person. Eve after mentioning my SW orientation, he still continued, and went on asking very difficult questions like archx64, 84 system architectures, which i have no background of. Did not clear round 1