OpenBoot 3.x Command Reference Manual

Emergency Procedures

Some OpenBoot systems provide the capability of commanding OpenBoot by means of depressing a combination of keys on the system's keyboard (i.e. a "keyboard chord").

Table C-1 describes the keyboard chords provided by SPARC-compatible systems. When issuing any of these commands, hold down the keys immediately after turning on the power to the SPARC system, and keep them pressed for a few seconds until the keyboard LEDs flash.

Table C-1 SPARC-Compatible System Keyboard Chords




Bypass POST. This command does not depend on security-mode. (Note: some systems bypass POST as a default; in such cases, use Stop-D to start POST.)




Enter diagnostic mode (set diag-switch? to true).


Enter Forth on TTYA instead of probing. Use fexit to continue with the initialization sequence. Useful if hardware is broken.


Reset NVRAM contents to default values. 

Note -

These commands are disabled if the PROM security is on. Also, if your system has full security enabled, you cannot apply any of the suggested commands unless you have the password to get to the ok prompt.