bootstrap loader


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bootstrap loader

[′büt‚strap ′lōd·ər]
(computer science)
A very short program loading routine, used for loading other loaders in a computer; often implemented in a read-only memory.

bootstrap loader

(operating system)
A short program loaded from non-volatile storage and used to bootstrap a computer.

On early computers great efforts were expended on making the bootstrap loader short, in order to make it easy to toggle in via the front panel switches. It was just clever enough to read in a slightly more complex program (usually from punched cards or paper tape), to which it handed control. This program in turn read the application or operating system from a magnetic tape drive or disk drive. Thus, in successive steps, the computer "pulled itself up by its bootstraps" to a useful operating state.

Nowadays the bootstrap loader is usually found in ROM or EPROM, and reads the first stage in from a fixed location on the disk, called the "boot block". When this program gains control, it is powerful enough to load the actual OS and hand control over to it. A diskless workstation can use bootp to load its OS from the network.
References in periodicals archive ?
If the programs are not found on drive A, the bootstrap loader then resumes its search by looking for the programs in one specific location on drive C.
PSD Allows Code To Be Downloaded From Any Channel - Infineon's C167CR MCU comes with a bootstrap loader that, if invoked during power-up, loads 16 instructions into the MCU's SRAM via the on-chip UART.
The boot code has to be programmed into the memory using a standard EPROM programmer or is available as a fixed ROM bootstrap loader on the MCU.