Embedded Interview Questions

Fri, 23 Jan 2026 19:53:00 +0000

Linux Theory

User space <-> Kernel space & Driver Interface

What communication method i use to communicating between User space to Kernel space.
How do the driver/device know which application is communicating with it.
write() api in user and kernel space, what are difference in arguments. From which header write() is included.
Explain ioctl calls and its handling in kernel and user space. What are the things application is dependent on to call a particular ioctl.
What is systemcall table

Device Tree & Platform

Why and How is Devise Tree used.
How is the device tree actually passed or accessed by the drivers.
How is the physical device be mapped to the driver device.
How is the platform bringup done? And what do we mean by platform devices.

Interrupts & Deferred Processing

How does interrupt is managed by the kernel? Describe each modules called which are done before calling isr and what are the propagation delay while interrupt is called.
How are interrupts managed by the kernel
What are arguments to a particular interrupt regestering function
Top half and bottom halfs, how are the complex isr managed.
Top halves and bottom halves

Memory Management & DMA

How kernel manages memory, like how malloc works
How is the TLD used to manage physical and virtual addresses? What exactly kernel does?
What is DMA and how does the driver handels it.
What is DMA and how it works?

Kernel Debugging & Virtual FS

How will you debug kernel crash or panic?
What is procfs and sysfs

Synchronization & Concurrency

Mutex semaphor explanation and difference
Race and deadlock conditions

Boot & Init

Linux boot process
What are init systems? Example systemd or any other init system

Misc Kernel / Language Concepts

Describe static and auto
What is volatile used for? Can const be volatile?
Write sudo code for character device driver

Embedded

Communication Protocols

I2C Start and stop bits, the data and clock config at start and stop
SPI lines

Programming Theory

Concurrency & OS Concepts

What is the difference between Mutex and SpinLock
What are mutex, threads, spinlocks

Data Structures

LinkList
Data Structures: Stack, Queues, Heap

C Language & Memory Model

C Concepts: BSS, Data Segment, ReadOnly segment.
Diff between structure and union and their sizes
What is pass by value and pass by reference look like?
Calculate the no. of elements inside of array if the array pointer is passed to a function.

Function Pointers & Declarations

Write declaration of An array of 5 pointers to a fucction. These functions are taking int arg and return int

Program Execution & Memory Layout

What exactly happens, what would be loaded in memory and which segments

main(){printf("Hello World")};
cc main.c
./a.out

Data Structures & Algorithms (DSA)

Arrays & Searching

Get the highest and 2nd most highest number from unsorted array without sorting it. int arr[10] = {5, 10, 15, 3, 9, 21, 7, 12, 2, 16}
Write a program to search inside of the array in 0(n/2) time complexity. Get a number from user and count the no. of times that number is present inside the array.

Bit Manipulation

Convert 0x12345678 to 0x34127856 using bit operators
Write a macro to toggle a given bit
Get a number in hex and start and end range number from user. Write a function which sets the number from the start till the end bit. The program should be independent from the machine architecture.
Count no of set bits in a number

Linked List Problems

Reverse a link list
Solve the error occured(sig. fault) in the last question of 1st round.
Write a program to find middle point of a linked list

Implement Linklist, its structure size, padding, allocating and print list wrappers.

Memory Management

Assume you have a memory pool of 1G allocated using malloc(). Now, implement my_malloc() and my_free() which will operate on this 1G chunk of memory to service multiple threads in an application. Try to implement the APIs which can alloc/free in O(1) time complexity.

Multithreading

Write a program which has 2 threads, 1 will take input from the user and another thread will do some processing on that input.
Program to print from 0 to 100 sequentially using 2 threads, 1st thread will print only even values and 2nd thread will print only odd values.

Debugging & Miscellaneous

Implement sizeof operator
Write a program to print diamond pattern
Print all prime numbers between 1 to 10.
Follow up: Store the prime numbers in singly linked-list.

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Embedded Interview Questions

Linux Theory

User space <-> Kernel space & Driver Interface

Device Tree & Platform

Interrupts & Deferred Processing

Memory Management & DMA

Kernel Debugging & Virtual FS

Synchronization & Concurrency

Boot & Init

Misc Kernel / Language Concepts

Embedded

Communication Protocols

Programming Theory

Concurrency & OS Concepts

Data Structures

C Language & Memory Model

Function Pointers & Declarations

Program Execution & Memory Layout

Data Structures & Algorithms (DSA)

Arrays & Searching

Bit Manipulation

Linked List Problems

Memory Management

Multithreading

Debugging & Miscellaneous