Information Technology Reference
In-Depth Information
Introduction
This chapter addresses topics related to booting and shutting down the sys-
tem. The first section covers key aspects of the system firmware on Sun
SPARC platforms. The boot process is discussed next. The third section
describes system run levels, the services available at the different run levels,
and how to move between the run levels (including shutdown). Also includ-
ed is a description of how to add a custom service at a selected run level.
The Boot PROM Firmware (OpenBoot)
The boot Programmable Read-Only Memory (PROM) of a system is used
to store the firmware that is executed immediately after the system hardware
finishes the Power On Self Test (POST). This firmware is called OpenBoot
and is the standard firmware for Sun systems.
OpenBoot is used to boot the operating system, run diagnostics, modify
boot-related parameters stored in nonvolatile RAM (NVRAM), and provide
a Forth interpreter.
Currently, three versions of OpenBoot are supported: version 2.x, version
3.x, and version 4.x. OpenBoot 2.x was introduced with SPARCstation 2 and
SPARCStation IPX systems. OpenBoot 3.x and 4.x are enhanced versions of
OpenBoot 2.x and are based on IEEE Standard 1275-1994, Standard for
Boot Firmware. OpenBoot 3.x and 4.x are used on Sun Ultra series and
newer SPARC platforms.
OpenBoot provides a command-line interface for the system console. The
command-line interface has two modes:
Restricted Monitor
—Allows the administrator to boot the operating
system, continue a suspended operation, or start the Forth Monitor. The
prompt for the Restricted Monitor is the greater than (
>
)
symbol.
➤
Forth Monitor
—Allows the administrator to boot the operating system,
run diagnostics, and modify system configuration parameters. The
prompt for the Forth Monitor is the word
ok
and is typically referred to
as the
OpenBoot prompt
.
➤
System-configuration parameters are stored in the system NVRAM. These
parameters determine the initial configuration and related communication
characteristics of the system and retain their value even if the power to the
system is shut off. The value of these parameters can be viewed and modified
using the OpenBoot commands.
