The document discusses microkernels in operating systems, highlighting their architecture, advantages, and disadvantages. Microkernels streamline the OS by removing non-essential components, enhancing modularity and security while posing challenges like increased resource usage and complexity. They are particularly useful in systems prioritizing scalability and security, as seen in platforms like Apple's macOS and iOS.

1. Name: Sampad Kar
Student Code: BWU/BTA/22/225
Course Name: Operating Systems
Course Code: PCC-CSM401
Group: D
Session: 2023-24

2. Microkernel
in
Operating
Systems

3. ● Introduction to Kernel
● What is a Microkernel?
● Microkernel Architecture
● Advantages of Microkernel
● Disadvantages of Microkernel
● Microkernel vs Monolithic Kernel
● Use Cases
● References
Agenda

4. ● A kernel is the core component of an
operating system. It plays a crucial role in
managing computer operations and
hardware.
● The kernel acts as a bridge between user
applications and the low-level data
processing performed by hardware.
● When an operating system is loaded, the
kernel is the first component to load into
memory and remains there until the system
shuts down. It handles tasks such as disk
management, task management, and memory
management.
Introduction to Kernel

5. 01
02
What is a Microkernel?
This method structures the operating system by
removing all nonessential components from the
kernel and implementing them as system and
user-level programs. The result is a smaller
kernel.
.
The primary idea behind a microkernel is to
provide only the essential services needed for
inter-process communication, memory
management, and basic hardware abstraction.

6. 01
02
Microkernel Architecture
The switch between User Mode and Kernel Mode is
done through system calls. The mode bit of kernel-
mode is 0, while the mode bit of user-mode is 1.
In a microkernel architecture, user-level processes run
until they need kernel-level services, initiating a system
call. The CPU switches to kernel mode, transferring
control to the microkernel. Here, the microkernel
executes the requested operation, which may involve
managing hardware or coordinating inter-process communication. After completion, the CPU transitions
back to user mode, allowing the user-level process to continue. Context switching involves saving and
restoring process state, ensuring seamless execution. This design enhances modularity and security, as
system-level services operate independently, minimizing the kernel's size and reducing the risk of critical
failures.

7. 01
02
03
Modularity:
The modular approach makes it
easier to maintain, extend, and
debug the system..
Advantages of Microkernel
Security:
Services run in user space, isolating
them from the core kernel, which
helps prevent security breaches from
affecting critical system functions..
Reliability:
Because microkernels have a small and
well-defined core, Faults in peripheral
components can be isolated and managed
without affecting the entire system.

8. 01
02
03
Increased System Resource Usage:
Microkernels may require more
System resources compared to
monolithic kernels due to the
overhead associated with
Managing separate processes and
IPC mechanisms.
Disadvantages of Microkernel
Performance Overhead:
Context switches between user and
kernel space, as well as message
Passing between components,
can introduce latency and
reduce overall system
performance.
Complexity of Implementation:
Designing and implementing a
microkernel-based operating system is
often more complex than developing a
monolithic kernel.

9. Monolithic Vs Microkernel

10. 01
02
Use Cases
The microkernel is specially useful in systems where
modularity, scalability and security plays an important
role.
Apple’s MacOS, iOS, iPadOS are based on microkernel

11. References
• https://www.javatpoint.com/microkernel-in-operating-
system#:~:text=Microkernels%20are%20secure%20since%20only,so%20it%20may%
20perform%20better.
• https://en.wikipedia.org/wiki/Microkernel
• https://www.geeksforgeeks.org/microkernel-in-operating-systems/

12. Thank You