Qualcomm interview questions

applied online and got an email from the HR then from the staff Engineer (interviewer) directly. a phone interview which takes around 50 min. Questions: some points from my resume that are related to embedded systems programming, then he goes to basic C/C++ questions. static variable, function , volatile, heap/stack mem. RTOS. he gave me a one line code and ask me where it will fail or any possible crash . don't remember exactly but the point is so u understand pointers well? then he asked me to write a code to calculate n factorial recursively and enter numbers in sorted order using linked list using C. very professional positive guy. but i was not prepared well. so didn't make it. now i got another interview for Software test engineer after 3 months. passed one phone interview, this time the questions r not that technical.