When a user program accesses system calls, it does so in kernel mode, not user mode.
This speeds up the boot process by taking advantage of a new kernel mode setting feature.
How can I change from one kernel mode to another?
Step three: the write system call causes a context switch from user mode to kernel mode.
Some of the programs that operate in kernel mode include interrupt handlers and kernel processes.
In a microkernel, only a few crucial functions, such as managing how memory and processor time are divided among applications and communications between software processes, run in kernel mode.
The send socket call causes a context switch from user mode to kernel mode.
A set of kernel mode procedures that executes as the result of a page fault. The pager and the image activator provide the operating system's memory management functions.
