Previous company experience and all technical stuff on Embedded system, C programming, domain knowledge.

Phone call interview: Whats static data type? volatile data type? what is structure ? Union ? Memory address space structure. processes ? Threads ? Inter-thread communication. Inter-process communication. Interrupts. system call. stack region. where does the global variables get stored ? what is mutex? Deadlock ? Atomic operation ? Questions related to DDR2: how to identify read and write waveforms how did you code for center aligned strobe while writing data ? blocking and non blocking (verilog) How latches are generated? Why do we need synchronization between controller and SDRAM? and how did you achieve it ? Onsite: First round was scripting. He had brought some codes and he asked me the operation. Then he showed me one file content and asked to fetch line data having "#define" at the start of line. What is deadlock ? second round was memory structure? How dats gets stored in memory. Bit-level C programming. Third round : He asked me global and local variables scope related questions by showing some codes. Then type casting related questions/coding. Fourth round was longer. we went to cafeteria and brought food in room only. They dint even let me eat. I dint even finish half from my plate. They kept asking me questions for next 4 rounds. This round was on DDR and bit level C programming. How to design number divide by 5 operation in Hardware ? Fifth round was on Data structure. Sixth round was on Verification and C++. What is formal verification ? Random constraints ? Assertions ? design Malloc function. I was not at all prepared for Verification. This was the reason for my rejection though I was good in all other rounds. Seventh round was on Computer Architecture. Pipeline, virtual memory, cache. ideally what should be the block size ?