Bootstrap: To start a computer by loading its OPERATING SYSTEM from disk storage into memory. The name alludes to the seeming absurdity of trying to lift oneself off the floor by pulling on one’s own bootstraps – since it is the operating system that enables a computer to read disks, then loading itself from disk would seem to be a similar impossibility. This paradox is resolved by the presence of a small program called the BOOTSTRAP LOADER, which resides permanently in the computer (stored in a ROM chip) and contains just sufficient code to read the rest of the operating system from disk. This process is informally called ‘booting’ or ‘booting up’ the computer.
The term was first used in computing to describe the process whereby a loader program, whose job it is to get other pieces of software into a machine, is itself loaded. This task was made possible by a very simple loader, wired into the hardware, that was just adequate to load a more extensive loader program, which then loaded everything else.
Bootstrapping commonly used now to denote bringing a computer to an operational state-that is, a state in which it accepts user commands-from either an un-powered state, or a powered but unresponsive state.
Booting a pc, for example, from an un-powered state-a cold boot-is initiated simply by switching the PC on-a one-touch operation that initiates a great deal of hardware testing and loading of software. Booting from a powered state-a warm boot-is usually initiated by pressing one or more keys or a button on the computer casing. It is normally done only to recover from a condition in which the computer is not behaving properly, for example, a “frozen” screen and unresponsive keyboard. A warm boot is also called a reboot or restart.
Bootstrap Loader: More formally called an Initial Program Loader (IPL), a small section of executable code, permanently stored in a ROM chip within the computer, whose sole function is to load into memory from DISK just that small part of a computer’s OPERATING SYSTEM needed to load the remainder of the operating system.