Why do kernels work

Kernel - what it does, how it works, and its types

The question of how it works is answered with a counter-question: What is a kernel not? The kernel is not a processor core, but the Operating system kernel. A kernel is also not an API or a framework.

Instead, you can Multi-kernel operating systems use different cores of a multi-core processor like a network of independent CPUs. How it works? Due to the special structure of the kernel, which is composed of a number of different components:

  • Because its lowest layer is close to the machine, it can communicate directly with the hardware, the processor and the memory. The functions of the kernel differ along the five layers, from process management to device manager. The top layer, on the other hand, has no machine access, but creates the transition to the software.
  • Application programs run on the operating system separately from the kernel and only use its functions. Communication between the program and hardware would not be possible without the kernel.
  • Several processes can run at the same time via a multitasking kernel. Basically, however, only one process can be processed by a CPU - unless there is a multi-core system. The scheduler takes care of the fast process change, which ultimately feels like multitasking.

From the components, the four functions of the kernel derive:

  1. Memory management: Controls how much memory is used where.
  2. Process management: Determines which processes the CPU can use when and for how long.
  3. Device driver: Mediated between hardware and processes.
  4. System call and security: Receives service requests from the processes.

When properly implemented, the functions of a kernel remain invisible to users. He works in his own world, the Kernel space. Files, programs, games, browsers - in short, everything the user sees can be found in the Userspace instead of. The interaction of both worlds runs through one System call interface, the SCI.