Sun Microsystems Netra T2000 - OpenBoot PROM; OpenBoot PROM Overview

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CHAPTER
3
OpenBoot PROM
This chapter describes the function, methods of obtaining, and configuration of the
OpenBoot PROM. Topics include:
■ “OpenBoot PROM Overview” on page 27
■ “Before You Obtain the ok Prompt” on page 28
■ “Obtaining the ok Prompt” on page 28
■ “OpenBoot PROM Configuration Variables” on page 31
■ “OpenBoot Emergency Procedures” on page 33
OpenBoot PROM Overview
The OpenBoot PROM is the low-level firmware that enables the server to boot into
the Solaris Operating System. Once running Solaris, the OpenBoot PROM releases
control of the server to the Solaris OS. Under certain conditions, the OpenBoot
PROM will regain control of the server. A list of scenarios under which OpenBoot
firmware control can occur follows:
■ When you deliberately place the system under firmware control in order to
execute firmware-based commands. This situation most often concerns you as an
administrator, since there will be times when you need to obtain the ok prompt.
■ By default, before the operating system is installed the system comes up under
OpenBoot firmware control.
■ When the auto-boot? OpenBoot variable is set to false, the system boots to
the ok prompt.
■ When the operating system is halted, the system transitions to run level 0 in an
orderly way.
■ When the operating system crashes, the system reverts to OpenBoot firmware
control.