Real-Time Operating System or RTOS technology is an on-demand and instant processing system that comes with multiple features. It helps developers get real-time processing for multiple tasks to be processed in a single core. If you want to pass the RTOS interview, we provide the essential questions and short answers in this article.
Many embedded developers and high-tech companies take advantage of real-time operating systems, and in case you want to pass the challenging interview, you should have experience in RTOS development. The embedded development job position basically needs practical work experience, and this is simple to pass the RTOS interview questions for those who have tried such systems before.
Tips to pass the challenging interview
If I were you, I would try to arrange a list of RTOS interview questions in an Excel file and provide short answers for each of them. This way, you have access to questions rapidly, and fortunately, you can review them using a mobile device.
Generally, the RTOS interview starts with basic questions about the concept of using real-time operating systems and continues with more experimental use cases of these software systems. Consequently, you need to keep up with your work experience and the skills you have learned during your studies.
Preparing for different question types proves your success in this stage to get your desired job position. If you want a simple and convenient interview, there is a need to read about diverse topics and know all the various questions that are likely to appear in this section.
You can regularly review the RTOS interview questions list using your mobile device to ensure you can bring the challenging topics down. The most important point is that you should present your practical skills during the interview for getting the job.
List of RTOS interview questions
Below is the list of RTOS interview questions, and it starts with the initial concepts of using real-time operating systems. As you go further in this section, there are more detailed topics that need specific work experience to answer correctly.
You should be precise and comprehensive in answering the RTOS interview questions as the recruiters want to understand your knowledge and skills completely. Giving the exact answer for the topics proves you have enough knowledge regarding the different concepts of real-time operating systems.
- What is RTOS?
- What is the difference between real-time operating systems and other approaches?
- What does kernel mean?
- Explain multitasking in operating systems.
- Explain stack overflow.
- What is a core dump?
- What is the purpose of using virtual memory?
- What is a time-sharing operating system?
- Explain volatile keywords and usage.
- How do you explain ISR?
- What is a thread?
What is RTOS?
Real-time systems are used to process many events simultaneously where numerous inputs from external sources are coming. These inputs must be processed in a short dedicated time within a deadline, and the system is rapidly switching between multiple tasks to respond to all of them.
The main application of Real-time operating is in robotics, embedded systems, control systems, and flight control, where there is a need for an instant and deterministic response for multiple inputs.
What is the difference between real-time operating systems and other approaches?
The general-purpose operating system can process multiple tasks simultaneously, but there is a big problem with these systems. Sometimes, we need a rapid response to inputs that are supposed to be high priorities.
Suppose you need a deterministic and rapid response in electric cars to pop out the airbags. In these cases, the OS may delay the execution of high-priority processes and would not respond at the right time. So, RTOS comes to schedule procedures to prioritize the critical inputs.
What does kernel mean?
The kernel is an imperative part of an operating system, and it manages other parts. It is supposed to be the core part of the OS, and we call it the main conductor of applications and data processing.
This component is responsible for process management, memory management, I/O control, and device management.
Explain the multi-tasking in operating systems.
At the same time, you need to process multiple tasks in the computer system or CPU. This is when the multi-tasking idea comes in, and this idea is the main part of the RTOS approach.
In the real world, the processor does the multi-tasking procedure by shifting between tasks with minimal intervals.
Explain stack overflow
Stack overflow is a runtime error when excessive memory is used on stack calls. This memory is limited in the program memory, and if exceeded, there is an error. So, the error can be caused if there is not enough memory for a program.
What is a core dump?
A core dump is a file that holds the essential information of crashes. This is the important solution to identify problems of applications when they crash, and in terms of unexpected terminations in processes, you can examine them to find out the problems.
Actual developers can use core dumps to spot the program issues.
What is the purpose of using virtual memory?
Virtual memory is an integral part of most operating systems that allows the user to run more applications than nominal considerations. This is a simulated file called page file or swap file, and it simulates RAM by using hardware storage.
What is a time-sharing operating system?
Time sharing operating system uses CPU scheduling to deliver dedicated operating time to each user in the system. This term also is called a multi-tasking system that allows multiple users with dedicated terminals to use the OS.
The most popular time-sharing operating systems are Windows, Macintosh, Linux, Android, and Apple iOS.
Explain volatile keywords and usage
The volatile qualifier addresses the variables that can be changed at any time. The volatile keywords are generally used when we work with GPIO or interrupts. These variables tell the compiler that our variables can be changed in other ways, such as I/O mapped memory location. If we don’t use the volatile keywords, the compiler may render the codes incorrectly during optimizations.
How do you explain ISR?
ISR or Interrupt Service Routine is a process that is performed with an interrupt request. You can request for pausing the coding process and running a specific line of code as a priority.
After the ISR is complete, the code can be resumed from the dedicated line of code. The ISR software process is the imperative part of RTOS, and it is used to respond to particular inputs and run the priorities during the process.
There are two main types of interrupts that are used in embedded systems or operating systems: Hardware and software interrupt. Hardware interrupts are triggered using an external component such as a button, and it informs the processor to stop the whole process and respond to the input.
A software interrupt is triggered if a condition in the code line reaches the desired result.
What is an ELF?
Executable and Linkable Format is a standard of executables, shareable libraries, and core dumps in embedded systems and OS. These files are in binary formats and are usually outputs of compiler or linker.
These files are important for programming and understanding the problems. If you have the right tool to examine and analyze them, you can use the ELF files to better understand the issues and code problems.
Conclusion
RTOS interview questions are based on hardware and software utilization, and you should have tried different embedded tools to pass the interview section. The success to overcome this section depends on reviewing different question types, and the best method is to give short and comprehensive answers. The RTOS interview questions are the basic topics of hardware and software implementations, and they continue with more specific approaches of using the software and hardware tools.
Frequently Asked Questions
How to pass the RTOS interview questions?
As an electronics and embedded developer, you should have used different tools and software procedures during your studies and work experience. Your work experience helps you answer the questions well and pass the section. The important point is to focus on giving exact and short answers.
How much time does it take from the beginning of RTOS interview questions to the end?
The interview time depends on the number of questions and the interviewer. If the job position is a junior-level job, you may have a simple interview.
How important is the RTOS interview questions part?
The interview section is the essential part of getting your job, and in many cases, you can not start your work without passing the questions.
What should be the answers to get the best result?
This depends on the question itself. If the interviewer wants detailed answers, you should give all the details. But, sticking to the exact topics is the crucial point generally.
What are the main topics that are likely to appear for the RTOS interview questions?
The main topics are hardware implementations, use cases, software issues, programming tools, and software testing regarding real time operating systems.
