The Kernel is the core of an operating system (OS). Linux Kernel is already three decades old and closes to 30 million code lines. Right now, it’s running on desktops, laptops, tablets, routers, servers, smartphones, lots of Internet of Things, and the most powerful computers in the world.
To talk about the Linux Kernel can go very long. Let’s check exactly what you need to know about it.
What is the Linux Kernel?
It is the most important component of the Linux OS. It is in charge of memory, peripheral devices, and central processing unit (CPU). Through the Linux Kernel (interface), communication between hardware and its processes is possible and efficient in terms of resources use. Linux Kernel is mostly written in C, a very popular programming language.
Kernel is a modern English word for “cyrnel”, which means seed. It seems it took this name to make a botanical reference meaning the seed from which everything else grows. In any case, this gives a clear image to understand that the Kernel inside Linux OS is the one controlling many functions in plenty of devices (hardware).
Linux Kernel is a monolithic one. In other words, it is a Kernel that includes memory, interprocess communication (IPC), CPU, file system management, system server calls, and device drivers. The best possible tools for communicating with hardware and execute simultaneous tasks. Due to this, processes work with fast speed.
A disadvantage of monolithic Kernel is that if one of its functions fails, all the system does it.
What are the Kernel mode and user mode?
The code the system executes has two modes for being run on CPUs: Kernel mode and user mode. With the first, all the code running has hardware’s unlimited access. But with the second, access is limited to the CPU and memory to the System Call Interface (SCI).
There is a division between Kernel and userspace also in the case of memory, building containers, security, etc. It helps to protect the system. If there is a failure on a user mode’s process, it won’t be so harmful since the Kernel can recover it. But if there’s a failure on a Kernel mode’s process, a situation can drive the complete system to crash.
Users can get privileges for accessing the Kernel space but just through some strict permissions in order to keep the security of this sensitive space.
Where is the Linux Kernel located?
Think about the Linux OS as a three-layer system: hardware, Linux Kernel, user processes.
- Hardware refers to a physical machine with RAM memory, input/output devices (graphics, networking, storage), and CPU, that basically reads and writes on the memory.
- Linux Kernel comes in between hardware and user processes. And it’s the software that lives in the memory and gives orders to the CPU to accomplish tasks.
- User processes. Programs run by users and managed by the Kernel.
What are the Linux Kernel’s main functions?
Being the core of the Linux OS, it has a lot of jobs, but we can review it in four main responsibilities.
- It provides device drivers for working as a breach or an interpreter between hardware and processes.
- It manages processes. Linux Kernel defines the processes that can use the CPU, the exact moment, and the amount of time for doing it.
- It administrates memory. Linux Kernel permanently follows up what is stored, where, and the amount of memory used for those tasks.
- It receives and services requests from the system and security processes.
Knowing a bit the power and capabilities of the Linux Kernel, it’s easier to understand its global popularity. Besides, being open-source, possibilities get multiply for users to modify it as they please. Try yourself and let your creativity be thrilled to bits!