OS Police. Kernel is the entire operating system. I mean the code that contains the main code and functionality. Usually because of what
Resource allocation
(CPU, Memory, IO, Device can be effectively used between processes)
Process Management
Process creation and uploading. Next process management
Memory Management
Main memory (RAM) for processes. To manage Virtual Memory (Secondary storage hard disk).
IO/Device Management
For IO devices, I do the monitoring and calling through the device driver.
Inter Process Communication
In Multi Programming systems, processes can be prevented from deadlock and starvation. That’s why I had to make contact with them. They usually do TCP/IP networking and pipes.
Scheduling
I use many processes at the same time. One turn after another. Scheduling is about who will take turns and how much time will be given to run.
System call and Interrupt Handling
System call is an API provided by the OS, for example file read, but a certain programming language reads a file, but then the OS police from the library. I have to call the file read API call. This is called a system call. Interrupt is an IO device. When tasks are completed or an event occurs, for example, 7 keys are pressed from the keyboard, then how does the OS communicate? Hey, I have received a key. That’s why I want to interrupt. Called like interrupt.
Security or Protection Management
This is from one process to another. Address space (the memory area in the main memory + virtual memory occupied by the file) is maintained by access control and fault control so as not to interfere.
There are three types of kernels.
Monolithic Kernel
The kernel functions that he just mentioned work in a single program, a single module, and a single address space. The good thing is that when all the functions are communicated, it is a single process, so communication takes from the same memory address space, so IPC is not needed. Time is fast. Device drivers are included once, so it’s quick to use the hardware. If the device is supported by the kernel, there is no need to include the device driver. The bad thing is that if one module fails, the entire kernel will crash. Large memory footprint. All together. Linux, BSDs (FreeBSD, OpenBSD, NetBSD), Solaris, OS-9, AIX, HP-UX, DOS, Microsoft Windows (95,98,Me), OpenVMS, XTS-400.
Micro Kernel
He just divided the kernel functions into modules and used separate address space. I mean file management is a process and scheduler is a process. The process communication file. IPC is required. The good thing is that even if a module fails, the kernel will not crash. It is flexible. Low installation footprint. Minix uses the micro kernel.
Hybrid
I used the combination above. Later windows use hybrid.