alustusohjelmia

Alustusohjelmia, often translated as bootloaders or startup programs, are essential pieces of software that manage the process of initiating a computer system. Their primary function is to load the operating system into the computer's memory after the initial power-on sequence. This process begins with the basic input/output system (BIOS) or unified extensible firmware interface (UEFI), which performs a power-on self-test (POST) to check hardware components. Once POST is complete, the BIOS/UEFI locates and executes the bootloader.

The bootloader then takes over, presenting options if multiple operating systems are installed or directly initiating the boot process for the default OS. It loads the necessary kernel and other critical system files from storage into RAM. Without a bootloader, the operating system would remain inaccessible, rendering the computer inoperable. Common examples of bootloaders include GRUB (GRand Unified Bootloader) for Linux systems and the Windows Boot Manager for Microsoft operating systems. These programs are critical for system startup and can be configured to offer advanced features like dual-booting or system recovery.