Arm Systems Architecture Engineer interview questions

The interview is a 1 hour panel interview with 3 ppl taking it. There were quite a few experienced guy on the Panel. They started out strong without any formalities or asking me to introduce myself. The interview was a deep dive into all the concepts of Computer Architecture. So basics and advance level of Comp Arch should be strong enough to answer. Then you would have 2 coding questions in the end. 1) The first coding question was something related to OS, which I didnt even understand while they explained it orally to me and I falied to do it. 2) The second one was a string rotation question, which was easy and I did it. But I was not prepared well on Comp Arch so I failed to clear it. but now it seems like an easy interview that could have been cleared.