Kjerneladning

Kjerneladning is a Danish term used to describe the process by which an operating system kernel is loaded into memory during boot and prepared to manage hardware and run initial services. It encompasses the sequence from initial bootstrapping to the handover to user-space.

The process typically involves several stages. A bootloader, such as GRUB in Linux or the Windows Boot Manager in Windows, loads a compressed kernel image into RAM and transfers control to the kernel. The kernel then decompresses the image, initializes essential subsystems (memory management, scheduler, interrupt handling), and initializes drivers for hardware. If present, an initial ramdisk or initramfs provides a temporary root filesystem that helps the kernel start up. Once the root filesystem is mounted, the kernel starts the initial user-space program (for example systemd, init, or a similar init system), which continues the boot process.

Dynamic aspects of kjerneladning include the loading of kernel modules after the core boot. The module system allows additional drivers and features to be brought online without rebooting, using tools such as modprobe to load or remove modules as needed.

Platform differences exist in how kjerneladning is implemented. Linux typically uses a bootloader to load a kernel image like vmlinuz and an initramfs; Windows follows a different boot chain centered around the NT kernel; embedded systems may use simplified boot sequences with compact kernel images.

Security considerations are important during kjerneladning. Secure Boot can verify kernel signatures to prevent tampering, and kernel lockdown or module signing policies can restrict loading unauthorized code during boot or runtime.

In summary, kjerneladning refers to the critical boot-time transition where the kernel is brought into operation and handed control to initialize the system.