The modern OS is a complex structure comprised of millions of lines of code. Not all information is released, and is this core components, or everything including additional apps that have been included?

Mac OS X Tiger (10.4) ~ 84 Million Lines of Code

Windows Vista (2009) ~50 Million Lines of Code

Debian 7.0 (2012) ~419 Million Lines of Code

The kernel of an OS is the minimal set of functions necessary to manage the system resources safely and efficiently. The kernel provides the most essential of services for the OS.

The CPU is divided into two sets: privileged and non-privileged. A privileged instruction performs critical operations. Only the OS kernel is allowed to execute privileged instructions.

A system call is a request from an application for an OS service. 

The OS structure was originally found on Access 2 Learn

Assistant Professor

Walter Wimberly is an Assistant Professor at a regional college in Tennessee, teaching Computer Science in the Software Engineering track. He works as a student advisor, oversees curriculum changes, develops new courses, and manages the advisory panel.
Walter taught full time for about 7 years, before going back into “industry” as a full stack Software Developer for a dozen years. There he focused on web based projects coding in JavaScript/jQuery and utilizing the Bootstrap CSS Framework on the front-end, and coding in PHP, ASP/ASP.Net, SQL on the back-end.

Since he loves teaching, he taught as an adjunct web and digital media classes for eight (8) years, while working in industry, and has since returned to teaching full time.

He has been married for over 25 years, and is father to several special needs boys. As such, he is working on some projects to help others who have special needs to be self-sufficient, and support the care givers of those with special needs. Check out his Autism blog for more info.

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