The User Interface

You can enter the OpenBoot environment in the following ways:

• By halting the operating system.

• By using the Stop-A key sequence from the keyboard. (This abruptly breaks execution of the operating system and should be used with caution.)

• By power-cycling the system. (If your system is configured to boot automatically, you can enter the OpenBoot environment by pressing Stop-A after the display console banner appears but before the system starts booting the operating system. If automatic booting is not enabled, the system will enter the OpenBoot environment on its own instead of booting the operating system.)

• When the system hardware detects an error from which it cannot recover. (This is known as a Watchdog Reset.)

The OpenBoot firmware provides three external interfaces: an interface for the operating system or other standalone programs, an interface for expansion bus plug-in boards (for example, SBus), and a command line interface for the user at the system console. This manual describes the third of these interfaces: the system console command line interface.

The command line interface has two modes:

• The Restricted Monitor

• The Forth Monitor

The Restricted Monitor

The Restricted Monitor provides a simple set of commands to initiate booting of the system, resume system execution, or enter the Forth Monitor. The Restricted Monitor is also used to implement system security. (See Chapter 3, Setting Configuration Parameters, for information on system security.)

The Restricted Monitor prompt is >. When you enter the Restricted Monitor, the following screen is displayed:

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Type b (boot), c (continue), or n (new command mode)
> 

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The Restricted Monitor commands are summarized in the following table.

Table 1-1 Restricted Monitor Commands

Command	Description
b [specifiers]	Boot the operating system.
c	Resume the execution of a halted program.
n	Enter the Forth Monitor.

The Forth Monitor

The Restricted Monitor functions b (for booting the system) and c (for resuming execution of a halted program) are available as the boot (see Chapter 2, Booting and Testing Your System) and go (see Chapter 5, Loading and Executing Programs) commands, respectively, in the Forth Monitor.

The Forth Monitor is an interactive command interpreter that gives you access to an extensive set of functions for hardware and software development, fault isolation, and debugging. A variety of system users, from end-users to system administrators to system developers, can use these functions.

The Forth Monitor prompt is ok. When you enter the Forth Monitor, the following screen is displayed:

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Type help for more information
ok 

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The Default Mode

The default mode in early OpenBoot systems is the Restricted Monitor. This was done mainly to provide a default look and feel similar to pre-OpenBoot systems.

The SPARCserver(TM) 690 system was the first to have the Forth Monitor as the default mode. All systems introduced thereafter also default to this mode. For such systems, the Restricted Monitor's only real function is to support system security. (Chapter 3, Setting Configuration Parameters, discusses system security.)

If you want to leave the Forth Monitor and get into the Restricted Monitor, type:

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ok old-mode 

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