Käynnistyslataajan

Käynnistyslataaja, often referred to as a bootloader, is a specialized piece of software responsible for initiating the operating system when a computer or other electronic device is powered on. Its primary function is to load the operating system kernel from storage into the computer's random-access memory (RAM) and then transfer control to the kernel, allowing the operating system to start up.

When a device is turned on, the firmware (like BIOS or UEFI on computers) performs initial hardware checks and then locates and executes the bootloader. The bootloader itself is typically stored in a non-volatile memory such as a hard drive, solid-state drive, or flash memory. It's a small program designed to be efficient and reliable, as its failure prevents the system from booting.

Different operating systems and hardware architectures may use different bootloaders. For example, on x86-based personal computers, GRUB (Grand Unified Bootloader) and LILO (LInux LOader) are common bootloaders for Linux systems, while Windows uses its own proprietary bootloader. Embedded systems often have simpler, custom-designed bootloaders tailored to their specific hardware and software requirements. The bootloader can also present options to the user, such as selecting which operating system to boot if multiple are installed.