Kernel RTOS Development Interview Questions

If you're looking for Kernel RTOS Development Interview Questions & Answers for Experienced or Freshers, you are in the right place. There are a lot of opportunities from many reputed companies in the world. According to research on Kernel, RTOS Development's average salary ranges from $73,000 to $134,000.

So, You still have the opportunity to move ahead in your career in Kernel RTOS Development. Mindmajix offers Advanced Kernel RTOS Development Interview Questions 2024 that helps you in cracking your interview & acquire your dream career as Kernel RTOS Developer.

Top 10 Kernel RTOS Development Interview Questions

1. In RTOS having 1okbytes of memory and your program for asking for 5kbytes and you got the null error
2. What is the need of creating 4GB of pages in Linux?
3. What are the rules you follow when you are writing a critical section of code?
4. What are the advantages and disadvantages of winCE compared to GPOS?
5. Why MFC is not Supporting Smartphones, This is also winCE mobile then why?
6. What is the difference between winCE4.0 and winCE5.0 Is there any specialty?
7. What are the levels in winCE architecture?
8. What are the SDKs developed by winCE?
9. What is the difference between normal OS and winCE OS?
10. What is CE Stands in winCCE?

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Best RTOS Interview questions

1. In RTOS having 1okbytes of memory and your program for asking for 5kbytes and you got the null error? why does it behave like this?

RTOS might be having 10k memory, might not have fragmentation problem, and the largest hole available to the user might be lesser than 5k, this condition might be one of the reasons for the NULL error.

2. What is the need of creating 4GB of pages in Linux?

Well, the simple answer is it can address so much of memory with available 32 address lines. 2 ^ 32 = 4 GB.

3. What are the rules you follow when you are writing a critical section of code?

1. Use Atomic Instructions
2. Remember to enable interrupts
3. Make the critical section code as small as possible. (Prefer no more than 20 instructions)
4. Prefer not to call other functions from the critical if u r calling, see that there is no critical section in the other function too. A critical section is bounded by Disable Interrupt and Enable Interrupt.

Check the example below.

fnA()

{
/* Critical Section Start */
Disable_Interrupt();
Some Instructions A ….
Call FnB();
/* do Something B */
Some Instructions B ….
/* Critical Section End */
}

fnB()
{
/* Critical Section Start */
Disable_Interrupt();
Some Instructions .. 
Enable_Interrupts();
/* Critical Section End */
}

Now the Enable_Interrupts in fnB() will enable the interrupts and hence “Some Instructions B ..” in fnA()  which should have been in the critical section will no more be in the critical section because the interrupts are already enabled!!
Please check if this condition is handled by the Enable and  Disable functions. If you want suggestions on how to solve  this problem, do revert back

4. What are the advantages and disadvantages of winCE compared to GPOS?

Advantages:

1. Supports various types of processor platforms
2. Possible to Customize the Kernel and can reduce its size (up to ~300KB kernel size)
3. Especially for the embedded device platforms

Disadvantages:

1. Process limits, max. 32 process at a time in WinCE 5.0
2. Limited space allocation for each process, 32MB/each process

5. Why MFC is not Supporting Smartphones, This is also winCE mobile then why?

Well, there is nothing to related limited H/w I believe, Because MFC is just a collection of classes designed using the Windows APIs, to provide ease of use.  So the proper answer may Be… To design any application on mobile. We have very limited APIs which users can directly use. Generally in an Embedded system (even in Soft RTOS also ), if the application design using less ( comfort )layer like MFC ( and others if it is there :) ), then your application would be more efficient. That’s why even in today’s era… The application written in Assembly is the most efficient application than others.

6. What is the difference between winCE4.0 and winCE5.0 Is there any specialty?

Speciality in the sense …

1. number of processes supported by wince 5.0 is more  than wince 4.0
2. memory mapping might be varying.

7.  What are the levels in winCE architecture?

There are four levels in Win CE architecture.

They are 

1. Hardware layer
2. OEM layer
3. OS layer
4. Application layer

8.  What are the SDKs developed by winCE?

MSFT standard SDK’s are,

1. Windows Mobile for Smartphone = Windows Mobile Standard.
2. Windows Mobile for Pocket PC = Windows Mobile Classic.
3. Windows Mobile for Pocket PC Phone Edition = Windows Mobile Professional.

9. What is the difference between normal OS and winCE OS?

Normal OS wince 

drivers run under Userspace(part of device manager)

kernel space

cannot be customized for embedded application

for embedded applications like mobile phones, thin client…

(exception Linux)

kernel – monolithic kernel- microkernel

10. What is CE Stands in winCCE?

In the name “Windows CE,” the letters “CE” is not an  abbreviation for anything, but rather they imply a number  of the precepts around which Windows CE is designed,  including “Compact,” Connectable,”  Compatible,” “Companion,” and “Efficient.”