Two rounds of phone screenings, followed by on-site interviews. The on-site interview process consisted of a an intro by the HR, followed by technical interviews by engineers and managers. You are expected to be an expert C programmer (you should know difference between static and non-static objects, stack and heap allocation, things like "volatile"), and an expert in firmware and device drivers. Storage experience (SCSI, RAID) helps.

what is Volatile memory- what is Non volatile memory- ex: ROM, Flash memeory, hard disk OS Concepts Context switching Preemptive scheduling Digital Designing concepts- How you will turn NAND into inverter What_is_the_difference_between_malloc_and_calloc Inline functions . Difference b/w structures and unions Where are the local, global, static, auto, register, extern, const, volatile variables are stored?

Initially it was a telephonic interview. I was contacted two weeks after the first interview for an onsite. The telephonic interview consisted of questions from C. Pointers, arrays and structures and bit manipulation. After that was an onsite interview, It was a really long process. Started at 9:30 am and finished at 5:30 in the evening. It was a lot more in detail. Pointers, arrays, structures, unions. Bit manipulation, assembly language, embedded and real time systems were part of the interview.