Qualcomm Interview Experience | Off-Campus 2021

Qualcomm Hyderabad Off-Campus Hiring for Driver Developer

Round 1: Basic round

Time: 1 hr

• What are structure and union, why is union preferred over structure in embedded systems.
• Structure padding concept

size of below structure
struct st
{
  short int   s;
  char        c;
  int         i;
} st_var;

• https://www.geeksforgeeks.org/structure-member-alignment-padding-and-data-packing/
• Storage class
• Memory layout
• Compiler phase
• How to check overflow in addition program of two numbers
• https://www.geeksforgeeks.org/check-for-integer-overflow/
• Write a program to rotated Linked list by K
• https://www.geeksforgeeks.org/problems/rotate-a-linked-list/1
• Rotation in a circular linked list program
• Resume based questions
• What are OS and kernel
• Write a program for array rotation
• https://www.geeksforgeeks.org/problems/rotate-array-by-n-elements/0

Round 2: Most of the questions related to OS only

Time: 1 hr

• What is the CPU scheduling algorithm, types
• PCB and process table, attribute of the process, process vs thread
• Dispatcher vs Scheduler.
• Which scheduling algorithm implemented in Linux
• Question-related GIT, Linux
• How booting happens in Linux, what is the init process in Linux?
• IPC, Mutex vs binary semaphore and which you will use
• Device driver, character driver
• Question-related to deadlock
• Virtual memory, segmentation, page table
• Input and output control in Linux

Round 3: Third round: 1.5 hrs

• Program to check overflow condition while adding two number
• Difference between 32bit and 64-bit processor
• Program to check 32bit or 64-bit processor
• https://www.quora.com/What-C-code-can-check-whether-the-OS-is-32-bit-or-64-bit
• Program array rotation by k
• Little endian vs big endian https://www.geeksforgeeks.org/little-and-big-endian-mystery/
• How to check little-endian and big-endian https://www.geeksforgeeks.org/little-and-big-endian-mystery/
• Resume based questions
• What is interrupt, types, interrupt life cycle, how it’s working in line https://linux-kernel-labs.github.io/refs/heads/master/lectures/interrupts.html
• What is CPU, the hierarchy of memory
• write one assembly language code and explain, How CPU executed any instructions with help of register, ALU, control signal,
• Behavior questions

Round 4: Time 1.5 hrs

• Note: first 30 min relates to the kernel and architecture of the system and two Hackerrank problems need to solve within the time limit.
• What kernel, how its works
• Process and threads, adv of threads
• Threads sharing the same address space
• User mode vs kernel mode
• Virtual memory
• If secondary memory is not available then virtual memory is required or not
• Device driver, character driver
• What API and its significance
• How users interacted with the kernel and vice versa step by step.
• How I/O call happened
• What is a system call
• What happened when the user requests any system call with respect to kernel
• Use of driver
• Role of CPU
• What happened when any process required memory access
• DMA concept
• Interprocess communication
• How to communicate to the driver
• More questions related to kernel, driver
• Memory leak, how to identified memory leak in system https://www.geeksforgeeks.org/what-is-memory-leak-how-can-we-avoid/
• Two Hackerrank programs First one is https://www.geeksforgeeks.org/delete-nodes-list-greater-x/ and the second one is https://www.geeksforgeeks.org/problems/decimal-equivalent-of-binary-linked-list/1
• Behavioral questions, culture fit questions

Verdict: Selected

Best of luck !!