The Minix operating system has kernel code and data, but also a number of operating system processes it calls server processes which have their own memory and code, but don't have direct access to the kernel data/code.

Two Minix server processes

• Process Manager
• FileSystem

The server processes execute in user mode.

Kernel code does the critical steps for system calls; that is, the steps that require kernel mode privilege.

Some parts of a system call may be handled by one or more of the operating server processes.

Sounds complicated!