"A system call is an interface between a user-space application and a service that the kernel provides. Because the service is provided in the kernel, a direct call cannot be performed; instead, you must use a process of crossing the user-space/kernel boundary. The way you do this differs based on the particular architecture. For this reason, I'll stick to the most common architecture, i386.
"In this article, I explore the Linux SCI, demonstrate adding a system call to the 2.6.20 kernel, and then use this function from user-space..."
