1) Screening round with Hiring Manager Hiring manager will share the Job requirement of the role and skills sets. Questions were asked about project done in past. 2) First Technical Round : a) Write C program to Detect i2c slave address of a sensor (Without i2c-detect) b) Reserve 1 Mbyte of kernel memory for your driver (Similar to PSTORE) c) Reverse bits in a number d) Is bit set, set bit, Reset bit e) Major and minor number required to implement i2c slave driver for 3 sensors connected on same bus. 2) Second Technical Round : a) What happens when i2c driver using same interrupt request line and interrupt received from one slave device only b) Implement driver and HAL ( in user space ) to get sensor data from two different sensor drivers asynchronously c) Difference between spinlock and mutex d) What happens when i2c sensor generating sensor data with 10Hz frequency but as per client speed is not same from user prospective e) Implement driver which accumulating sensor data as per set sampling time and sharing latest data with user space based on request f) Which is better level triggered or edge triggered g) Explain Linux kernel for input/output subsystem h) Write macro to set all number bits for a given number 3) 3rd Technical Round a) Explain work-queues b) Explain interrupts c) Explain watchdog d) Kernel memory allocation techniques e) How you can reserve kernel memory f) Why cache invalidation g) What is iommu h) Types of DMA memory allocation techniques - With cache and without i) How you debug kernel memory leaks j) Kernel configuration macro used to detect memory leaks k) Remove given pointer in Singly list ( Head not given ) l) Detect loop in singly linked list 4) 4th Round a) C program and find error. (You can not change base address of an array) b) Why volatile c) What happens to system when booted and first instructions gets executed.( from TLB miss prospective) d) What is the job of memory management hw unit e) What are different ways to optimize memory usage f) Linux power optimization techniques g) Boot time optimization h) Memory usage optimization techniques