Computing Dictionary
bootstrap loader definition
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.
(2005-04-12)
