Microkernel

A microkernel or microkernel called an operating system kernel. The microkernel features as opposed to a monolithic kernel only basic features - usually only functions for memory and process management, as well as basic functions for synchronization and communication. All other functions are stored as separate processes (server) that communicate with the querying programs (client), or as a library, which is included by the querying programs, implemented in user mode.

Micronucleus are particularly suitable for implementing distributed operating systems since the operating system components can be outsourced.

Development

Due to the poor performance of some earlier implementations micronuclei have the reputation of being rather slow and confusing.

However, there are now kernel, the (sometimes with loss of portability ) provide high data throughput by minimizing other functionality, but also by strong optimization and so gaining interest. So L4 works only with ten commands.

On the PowerPC architecture extremely powerful micronuclei are feasible, since the context switch can be performed much faster than on older architectures such as x86.

Benefits

Disadvantages

Known micronuclei

  • Do GNU Mach
  • Fiasco
  • L4Ka :: Pistachio
  • L4Ka :: Hazelnut

Operating systems that are based on micronuclei

  • AmigaOS
  • Amoeba
  • ChorusOS
  • GNU / Hurd
  • L4Linux
  • Minix
  • MkLinux
  • MorphOS
  • PC / GEOS
  • PikeOS
  • QNX Neutrino
  • Singularity
  • Symbian OS
  • Symobi ( uses the Sphere micronucleus )
  • Tru64 UNIX
  • ThreadX

Windows NT is, even if this is often falsely claimed no microkernel system. It belongs to the group of hybrid kernel. Andrew S. Tanenbaum writes: "Windows NT 3.1 was a half-hearted attempt at a microkernel system, but it was not done correctly, and the performance was not good enough on the hardware of the early 1990s, so gave you the idea for a while. "

Also, the Darwin kernel in Mac OS X is a hybrid kernel.

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