NVIDIA Senior Systems Software Engineer interview questions

Round 3: What is NVMe BAR address? Explain the process of bootloading? Explain the architecture of a generic flash controller. Consider NVMe front end and a Flash back end. Discuss various design considerations. Why are NVMe submission and receival queues needed? Explain inter process communication (IPC) and the need for it. Round 4: Declare: Pointer to an integer Array of pointers Pointer to an array Function pointers Array of function pointers Puzzle: Let’s say there is a 6x6 matrix shelves. Can you place 14 bottles in these shelves in such a way that every row and every column will have even number of bottles? There are two 32 bit numbers A & B. Write a macro to mask n bits (towards the right) of position p bit of A to B. Let’s say you are the person in charge for booting the system and getting up and running. Your source code in eMMC drive has to come to RAM and then the reset vector trigger should start the main code. But unfortunately booting failed. How will you debug, what are the steps you are going to take? Assume you have a eMMC coming from the customer company. You have the privilege to ask questions to the customer company, what do you ask them if you have to? Round 5: What is the role of ADC? Let’s say I have an SPI bus and I connected ADC to it which reads analog and gives digital in the uP scope. How will you design your sampling system. Explain different signals you have analyzed using digital signal analyzers. When did you go to analog oscilloscopes in your career? Can you design the concept of a C++ functionality of a fraction class in C. The design should be able to maintain numerator and denominator private but exposing the function to print the fraction, modify the fraction. This should cover public & private variables, functions. [Hint: Static] Round 6: There are 3 bags with 2 balls in each bag. The balls in 3 bags are WW, WB, BB respectively. If I pick a ball from a bag and find that the ball is W, what is the probability that the next ball I pick from the same bag is also W? I have a structure, Struct data{ U32 data; Struct data next; }; I have a memory where my data is being written. How will you detect if some other process has come and corrupted your data. [Hint: What is that you add to the structure to achieve this goal?] Round 7: I have a single linked list. I want to delete a node. I am giving you the node address. How will you do it in O(1) time complexity? Write a C code to find the number of 1s in a given number? Can you optimize it? Let’s say you are capturing images at 30 frames per second on a host CPU. You are given a discrete GPU to process these images. You have a DMA to transfer the images from the CPU RAM to GPU. How are you going to design this system? Can you explain the cache algorithms? Priority inversion with an example of 3 threads?