Microkernel
lastmod 2018-08-17created 2015-01-281 edits
In computer science, a microkernel is a kernel that provides the mechanisms needed to implement an operating system. These mechanisms include low-level address space management, thread management, and inter-process communication (IPC). If the hardware provides multiple rings or CPU modes, the microkernel is the only software that runs at the most privileged level (generally called supervisor or kernel mode). Traditional operating system functions such as device drivers, protocol stacks, and file systems are removed from the microkernel and run in user space. In terms of source code size, microkernels generally tend to have 10,000 lines of code or fewer. MINIX, for example, has 4,000 lines of code.
Microkernels were developed in the 1980s as the computing world changed and problems arose in adapting existing mono-kernels to these new systems.