C H A P T E R 3

Setting Configuration Variables

This chapter describes how to access and modify non-volatile RAM (NVRAM) configuration variables.

System configuration variables are stored in the system NVRAM . These variables determine the start-up machine configuration and related communication characteristics. You can modify the values of the configuration variables, and any changes you make remain in effect even after a power cycle. Configuration variables should be adjusted cautiously.

The procedures described in this chapter assume that the user interface is active. See Chapter 1 for information about entering the user interface.

lists a typical set of NVRAM configuration variables defined by IEEE Standard 1275-1994 .

TABLE 3-1 Standard Configuration Variables

Variable	Typical Default	Description
auto-boot?	true	If true, boot automatically after power on or reset.
boot-command	boot	Command that is executed if auto-boot? is true.
boot-device	disk net	Device from which to boot.
boot-file	empty string	Arguments passed to booted program.
diag-device	net	Diagnostic boot source device.
diag-file	empty string	Arguments passed to booted program in diagnostic mode.
diag-switch?	false	If true, run in diagnostic mode.
fcode-debug?	false	If true, include name fields for plug-in device FCodes.
input-device	keyboard	Console input device (usually keyboard , ttya , or ttyb ).
nvramrc	empty	Contents of NVRAMRC .
oem-banner	empty string	Custom OEM banner (enabled by oem-banner? true ).
oem-banner?	false	If true, use custom OEM banner.
oem-logo	no default	Byte array custom OEM logo (enabled by oem-logo? true ). Displayed in hexadecimal.
oem-logo?	false	If true, use custom OEM logo (else, use Sun logo).
output-device	screen	Console output device (usually screen , ttya , or ttyb ).
screen-#columns	80	Number of on-screen columns (characters/line).
screen-#rows	34	Number of on-screen rows (lines).
security-#badlogins	no default	Number of incorrect security password attempts.
security-mode	none	Firmware security level (options: none , command , or full ).
security-password	no default	Firmware security password (never displayed).
use-nvramrc?	false	If true, execute commands in NVRAMRC during system start-up.

An dditional configuration variable is defined by the SBus binding to IEEE Standard 1275-1994 . The variable is shown in .

TABLE 3-2 SBus Configuration Variable

Variable	Typical Default	Description
sbus-probe-list	0123	Which SBus slots to probe and in what order.

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Note - Different OpenBoot implementations may use different defaults and/or different configuration variables.

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Displaying and Changing Variable Settings

NVRAM configuration variables can be viewed and changed using the commands listed in .

TABLE 3-3 Viewing or Changing Configuration Variables

Command	Description
printenv	Display current variables and current default values. printenv variable shows the current value of the named variable.
setenv variable value	Set variable to the given decimal or text value . (Changes are permanent, but often take effect only after a reset.)
set-default variable	Reset the value of variable to the factory default.
set-defaults	Reset variable values to the factory defaults.
password	Set security-password

The following pages show how these commands can be used.

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Note - Solaris provides the eeprom utility for modifying OpenBoot configuration variables.

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To display a list of the current variable settings on your system, type:

In the displayed, formatted list of the current settings, numeric variables are often shown in decimal.

To change a variable setting, type:

variable-name is the name of the variable. value is a numeric value or text string appropriate to the named variable. A numeric value is interpreted as a decimal number, unless preceded by 0x , which is the qualifier for a hexadecimal number.

For example, to set the auto-boot? variable to false , type:

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Note - Many variable changes do not affect the operation of the firmware until the next power cycle or system reset at which time the firmware uses the variable's new value.

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You can reset one or most of the variables to the original defaults using the set-default variable and set-defaults commands.

For example, to reset the auto-boot? variable to its default setting (true), type:

To reset most variables to their default settings, type:

On SPARC systems, it is possible to reset the NVRAM variables to their default settings by holding down Stop-N while the machine is powering up. When issuing this command, hold down Stop-N immediately after turning on the power to the SPARC system, and keep it pressed for a few seconds or until you see the banner (if the display is available). This is a good technique to force a SPARC compatible machine's NVRAM variables to a known condition.

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Setting Security Variables

The NVRAM system security variables are:

• security-mode

• security-password

• security-#badlogins

security-mode can restrict the set of operations that users are allowed to perform from the User Interface. The three security modes, and their available commands, are listed in the following table in the order of most to least secure.

TABLE 3-4 Commands Available for security-mode Settings

Mode	Commands
full	All commands except for go require the password.
command	All commands except for boot and go require the password.
none	No password required (default).

Command Security

With security-mode set to command :

• A password is not required if you type the boot command by itself. However, if you use the boot command with an argument , a password is required.

• The go command never asks for a password.

• A password is required to execute any other command.

Examples are shown in the following screen.

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Caution - It is important to remember your security password and to set the security password before setting the security mode. If you forget this password, you cannot use your system; you must call your vendor's customer support service to make your machine bootable again.

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To set the security password and command security mode, type the following at the ok prompt:

The security password you assign must be between zero and eight characters. Any characters after the eighth are ignored. You do not have to reset the system; the security feature takes effect as soon as you type the command.

If you enter an incorrect security password, there will be a delay of about 10 seconds before the next boot prompt appears. The number of times that an incorrect security password is typed is stored in the security-#badlogins variable.

Full Security

The full security mode is the most restrictive. With security-mode set to full :

• A password is required any time you execute the boot command.

• The go command never asks for a password.

• A password is required to execute any other command.

Here are some examples.

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Caution - It is important to remember your security password and to set the security password before setting the security mode.. If you forget this password, you cannot use your system; you must call your vendor's customer support service to make your machine bootable again.

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To set the security password and full security, type the following at the ok prompt:

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Changing the Power-on Banner

The banner configuration variables are:

• oem-banner

• oem-banner?

• oem-logo

• oem-logo?

To view the power-on banner, type:

The banner for your system may be different.

The banner consists of two parts: the text field and the logo (over serial ports, only the text field is displayed). You can replace the existing text field with a custom text message using the oem-banner and oem-banner? configuration variables.

To insert a custom text field in the power-on banner, type:

The system displays the banner with your new message, as shown in the preceding screen.

The graphic logo is handled differently. oem-logo is a 512-byte array, containing a total of 4096 bits arranged in a 64 x 64 array. Each bit controls one pixel. The most significant bit (MSB) of the first byte controls the upper-left corner pixel. The next bit controls the pixel to the right of it, and so on.

To create a new logo, first create a Forth array containing the correct data; then copy this array into oem-logo . The array is then installed in oem-logo with $setenv . The example below fills the top half of oem-logo with an ascending pattern.

To restore the system's original power-on banner, set the oem-logo? and oem-banner? variables to false .

Because the oem-logo array is so large, printenv displays approximately the first 8 bytes (in hexadecimal). To display the entire array, use the phrase oem-logo dump . The oem-logo array is not erased by set-defaults , since it might be difficult to restore the data. However, oem-logo? is set to false when set-defaults executes, so the custom logo is no longer displayed.

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Note - Some systems do not support the oem-logo feature.

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Input and Output Control

The console is used as the primary means of communication between OpenBoot and the user. The console consists of an input device, used for receiving information supplied by the user, and an output device, used for sending information to the user. Typically, the console is either the combination of a text/graphics display device and a keyboard or an ASCII terminal connected to a serial port.

The configuration variables related to the control of the console are:

• input-device

• output-device

• screen-#columns

• screen-#rows

You can use these variables to assign the power-on defaults for the console. These values do not take effect until after the next power cycle or system reset.

Selecting Input and Output Device Options

The input-device and output-device variables control the firmware's selection of input and output devices after a power-on reset. The default input-device value is keyboard and the default output-device value is screen . The values of input-device and output-device must be device specifiers. The aliases keyboard and screen are often used as the values of these variables.

When the system is reset, the named device becomes the initial firmware console input or output device. (If you want to temporarily change the input or output device, use the input or output commands described in Chapter 4 )

To set ttya as the initial console input device, type:

If you select keyboard for input-device , and the device is not plugged in, input is accepted from a fallback device (typically ttya ) after the next power cycle or system reset. If you select screen for output-device , but no frame buffer is available, output is sent to the fall-back device after the next power cycle or system reset.

To specify an SBus frame buffer as the default output device (especially if there are multiple frame buffers in the system), type:

Serial Port Characteristics

The following values represent the typical range of communications characteristics for serial ports:

• baud = 110, 300, 1200, 2400, 4800, 9600, 19200, or 38400 bits/second

• #bits = 5, 6, 7, or 8 (data bits)

• parity = n (none), e (even), or o (odd), parity bit

• #stop = 1 (1), . (1.5), or 2 (2) stop bits

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Note - rts/cts and xon/xoff handshaking are not implemented on some systems. When a selected protocol is not implemented, the handshake variable is accepted but ignored; no messages are displayed.

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Selecting Boot Options

You can use the following configuration variable to determine whether or not the system will boot automatically after a power cycle or system reset.

• auto-boot?

If auto-boot? is true and if OpenBoot is not in diagnostic mode, the system boots automatically after a power-cycle or system reset using the boot-device and boot-file values.

These variables can also be used during manual booting to select the boot device and the program to be booted. For example, to specify default booting from the network server, type:

Changes to boot-file and boot-device take effect the next time that boot is executed.

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Controlling Power-on Self-Test (POST)

The Power-on Testing variables are:

• diag-switch?

• diag-device

• diag-file

• diag-level

Setting diag-switch? to true causes the function diagnostic-mode? to return true . When diagnostic-mode? returns true , the system:

• Performs more thorough self tests during any subsequent power-on or system reset process.

• May display additional status messages (the details are implementation dependent).

• Uses different configuration variables for booting. (For more details on the effects on the boot process, see Chapter 2 )

Most systems have a factory default of false for the diag-switch? variable. To set diag-switch? to true , type:

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Note - Some systems have a hardware diagnostic switch that also cause diagnostic-mode? to return true. Such systems run the full tests at power-on and system reset if either the hardware switch is set or diag-switch? is true.

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Note - Some implementations enable you to force diag-switch? to true by using an implementation-dependent key sequence during power-on. Check your system's documentation for details, or see Appendix C."

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To set diag-switch? to false , type:

When not in diagnostic mode, the system does not announce the diagnostic tests as they are performed (unless a test fails) and may perform fewer tests.

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Using nvramrc

The nvramrc configuration variable whose contents are called the script , can be used to store user-defined commands executed during start-up.

Typically, nvramrc is used by a device driver to save start-up configuration variables, to patch device driver code, or to define installation-specific device configuration and device aliases. It can also be used for bug patches or for user-installed extensions. Commands are stored in ASCII, just as the user would type them at the console.

If the use-nvramrc? configuration variable is true , the script is evaluated during the OpenBoot start-up sequence as shown:

• Perform power-on self-test (POST)

• Perform system initialization

• Evaluate the script (if use-nvramrc? is true)

• Execute probe-all (evaluate FCode)

• Execute install-console

• Execute banner

• Execute secondary diagnostics

• Perform default boot (if auto-boot? is true)

It is sometimes desirable to modify the sequence probe-all install-console banner . For example, commands that modify the characteristics of plug-in display devices may need to be executed after the plug-in devices have been probed, but before the console device has been selected. Such commands would need to be executed between probe-all and install-console . Commands that display output on the console would need to be placed after install-console or banner .

This is accomplished by creating a custom script which contains either banner or suppress-banner since the sequence probe-all install-console banner is not executed if either banner or suppress-banner is executed from the script. This allows the use of probe-all , install-console and banner inside the script, possibly interspersed with other commands, without having those commands re-executed after the script finishes.

Most User Interface commands can be used in the script. The following cannot:

• boot

• go

• nvedit

• password

• reset-all

• setenv security-mode

Editing the Contents of the Script

The script editor, nvedit , lets you create and modify the script using the commands listed in .

TABLE 3-5 Commands Affecting NVRAMAC

Command	Description
nvalias alias device-path	Stores the command "devalias alias device-path" in the script. The alias persists until either nvunalias or set-defaults is executed.
$nvalias	Performs the same function as nvalias except that it takes its arguments, name-string and device-string , from the stack.
nvedit	Enters the script editor. If data remains in the temporary buffer from a previous nvedit session, resumes editing those previous contents. If not, reads the contents of nvramrc into the temporary buffer and begins editing it.
nvquit	Discards the contents of the temporary buffer, without writing it to nvramrc . Prompts for confirmation.
nvrecover	Recovers the contents of nvramrc if they have been lost as a result of the execution of set-defaults ; then enters the editor as with nvedit . nvrecover fails if nvedit is executed between the time that the nvramrc contents were lost and the time that nvrecover is executed.
nvrun	Executes the contents of the temporary buffer.
nvstore	Copies the contents of the temporary buffer to nvramrc ; discards the contents of the temporary buffer.
nvunalias alias	Deletes the specified alias from nvramrc .
$nvunalias	Performs the same function as nvunalias except that it takes its argument, name-string , from the stack.

The editing commands shown in are used in the script editor.

TABLE 3-6 Script Editor Keystroke Commands

Keystroke	Description
Control-B	Moves backward one character.
Escape B	Moves backward one word.
Control-F	Moves forward one character.
Escape F	Moves forward one word.
Control-A	Moves backward to beginning of the line.
Control-E	Moves forward to end of the line.
Control-N	Moves to the next line of the script editing buffer.
Control-P	Moves to the previous line of the script editing buffer.
Return (Enter)	Inserts a new line at the cursor position and advances to the next line.
Control-O	Inserts a newline at the cursor position and stays on the current line.
Control-K	Erases from the cursor position to the end of the line, storing the erased characters in a save buffer. If at the end of a line, joins the next line to the current line (i.e. deletes the newline).
Delete	Erases the previous character.
Backspace	Erases the previous character.
Control-H	Erases the previous character.
Escape H	Erases from beginning of word to just before the cursor, storing erased characters in a save buffer.
Control-W	Erases from beginning of word to just before the cursor, storing erased characters in a save buffer.
Control-D	Erases the next character.
Escape D	Erases from the cursor to the end of the word, storing the erased characters in a save buffer.
Control-U	Erases the entire line, storing the erased characters in a save buffer.
Control-Y	Inserts the contents of the save buffer before the cursor.
Control-Q	Quotes the next character (i.e. allows you to insert control characters).
Control-R	Retypes the line.
Control-L	Displays the entire contents of the editing buffer.
Control-C	Exits the script editor, returning to the OpenBoot command interpreter. The temporary buffer is preserved, but is not written back to the script. (Use nvstore afterwards to write it back.)

Activating the Script

Use the following steps to create and activate the script:

At the ok prompt, type nvedit.

Edit the script using editor commands.

Type Control-C to get out of the editor and back to the ok prompt.

If you have not yet typed nvstore to save your changes, you may type nvrun to execute the contents of the temporary edit buffer.

1. Type nvstore to save your changes.

2. Enable the interpretation of the script by typing:

3. Type reset-all to reset the system and execute the script, or type:

to execute the contents directly.

The following example shows you how to create a simple colon definition in the script.

Notice the nvedit line number prompts (0:, 1:, 2:, 3:) in the above example. These prompts are system-dependent.