boot

boot v.,n.  [techspeak; from `by one's bootstraps'] To
   load and initialize the operating system on a machine.  This usage
   is no longer jargon (having passed into techspeak) but has given
   rise to some derivatives that are still jargon.

   The derivative `reboot' implies that the machine hasn't been down
   for long, or that the boot is a {bounce} (sense 4) intended to
   clear some state of {wedgitude}.  This is sometimes used of
   human thought processes, as in the following exchange: "You've
   lost me."  "OK, reboot.  Here's the theory...."

   This term is also found in the variants `cold boot' (from
   power-off condition) and `warm boot' (with the CPU and all
   devices already powered up, as after a hardware reset or software
   crash).

   Another variant: `soft boot', reinitialization of only part of a
   system, under control of other software still running: "If
   you're running the {mess-dos} emulator, control-alt-insert will
   cause a soft-boot of the emulator, while leaving the rest of the
   system running."

   Opposed to this there is `hard boot', which connotes hostility
   towards or frustration with the machine being booted: "I'll have
   to hard-boot this losing Sun."  "I recommend booting it
   hard."  One often hard-boots by performing a {power cycle}.

   Historical note: this term derives from `bootstrap loader', a short
   program that was read in from cards or paper tape, or toggled in
   from the front panel switches.  This program was always very short
   (great efforts were expended on making it short in order to
   minimize the labor and chance of error involved in toggling it in),
   but was just smart enough to read in a slightly more complex
   program (usually from a card or paper tape reader), to which it
   handed control; this program in turn was smart enough to 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 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.