First round consisted of basic C questions like what are volatile variables, extern key-word, scope of global vs extern variables, etc. Then there were some questions on data structures (primarily linked lists, like write a function to add a new head node), followed by a brain teaser. The second round of interview was with the hiring manager. It was relatively very casual compared to the first round. We just discussed about what all projects are being done at EchoStar, what will my role as an SW Intern be, etc.