What is Linux kernel source?

What is Linux kernel source?

The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was conceived and created in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU operating system, which was created as a free replacement for UNIX.

What is kernel compilation in Linux?

Linux kernel is the life force of all Linux family of operating systems including Ubuntu, CentOS, and Fedora. For most part, you don’t need to compile the kernel, as it is installed by default when you install the OS. To enable support for a new hardware that is not currently supported by the default kernel.

Should I compile my own kernel?

Compiling your own kernel allows you to participate in the kernel development process, whether that is simple stuff such as supplying PCI/USB device IDs for an existing driver that may make a newer device work for you, to getting deeply involved in the fray of core kernel development.

What does it mean when a driver is in kernel mode?

All code that runs in kernel mode shares a single virtual address space. This means that a kernel-mode driver is not isolated from other drivers and the operating system itself. If a kernel-mode driver accidentally writes to the wrong virtual address, data that belongs to the operating system or another driver could be compromised.

When does the processor switch between kernel and user mode?

The processor switches between the two modes depending on what type of code is running on the processor. Applications run in user mode, and core operating system components run in kernel mode. While many drivers run in kernel mode, some drivers may run in user mode.

Which is the default kernel in CentOS 7?

On my fresh CentOS 7 install it defaults to 5. Also if on RedHat you’re installing new kernel from RPM package you should use rpm -ivh, not rpm -Uvh: the former will keep the older kernel in place while the later will replace it. Debian keeps old kernels but don’t automatically removes them.