The NVRAM utility provides another method of configuring a subset of terminal parameters and provides access to some parameters that are not available through other configuration methods. The utility also allows you to set security levels for the optional security keyboard.

This section describes how to use the NVRAM utility and lists the contents of NVRAM.

Starting the NVRAM Utility

To start the NVRAM utility, type:

> nv 
NVRAM Utility 
C [add] - change location add
D - display contents
Q - return to monitor
L - load defaults
R - reload NVRAM values
S - save new values
->>

Type NVRAM utility commands after the ->> prompt, and follow all commands with a carriage return.

NVRAM Utility Commands

Table 11-6 lists NVRAM utility commands, options, syntax, and functions.

NVRAM commands modify a copy of NVRAM residing in RAM. The NVRAM utility does not write changes to NVRAM until you use the s (save) command.

Table 11-6 General-Purpose NVRAM Utility (nv) Commands

Sample NVRAM Utility Sessions

The following examples show how to use the NVRAM utility. In the NVRAM utility, you enter new values in hexadecimal notation. The symbols used in the examples are:

>	The prompt generated by the Boot Monitor
->>	The NVRAM utility prompt
xx	The previous values stored in NVRAM

Changing Contents Byte by Byte

In the following example of how to change NVRAM contents, the terminal's Ethernet address is re-entered after having been accidentally erased. The Ethernet address is 00 00 A7 10 24 14.

>  nv
NVRAM Utility
C [add] - change location add
D - display contents
Q - return to monitor
L - load defaults 
R - reload NVRAM values
S - save new values
->>  l 
->>  c 04 
004: xx ?  00
005: xx ?  00
006: xx ?  A7
007: xx ?  10
008: xx ?  24 
009: xx ?  14
00A: xx ?  q 
->>  s
Are you sure ?  y 
->>  q
>  rs  

1. Start the NVRAM utility and type c 04 to start changing the Ethernet address (the Ethernet address starts at location 0x4).
   

2. Type the first pair of numbers of the Ethernet address and press Return.
   

3. In the same way, type the remaining pairs. At the prompt 009: xx ? you have typed the entire Ethernet address and you can type q to stop entering numbers.
   

4. Type s to save, and y after the question, Are you sure?
   

5. Type q to end the NVRAM utility session and resume using the Boot Monitor utility.
   

6. You can reboot the terminal by typing the rs (reset) command.
   

In the following example, the first bit in byte 0x35 is changed. This bit enables the display of the NCD logo at boot time and is set to 1 by default.

>  nv
NVRAM Utility
C [add] - change location add
D - display contents
Q - return to monitor
L - load defaults
R - reload NVRAM values
S - save new values
->>  l
->>  c 35
035: 8A ?  0A
036: A0 ?  q
->>  s
Are you sure ?  y
->>  q
>  rs

1. Start the NVRAM utility and type c 35 to start changing byte 0x35.
   

2. Compute the new value of the byte in binary and then convert it to hexadecimal. Assuming the other bits have their default values, the new value of the byte is 00001010, or 0A in hexadecimal. Enter the new value.
   

3. At the next ? prompt, type q to stop entering numbers.
   

4. Type s to save, and y after the question, Are you sure?
   

5. Type q to end the NVRAM utility session and resume using the Boot Monitor utility.
   

6. You can reboot the terminal by typing the rs (reset) command.
   

Table 11-7 lists the locations, descriptions, and permitted values for parameters stored in the shared portion of version 4 of the NVRAM layout, which is the current version. The corresponding remote configuration parameters (if any) are also listed.

NVRAM is divided into shared and server-only portions. The shared portion of NVRAM includes data used internally by the Boot Monitor and parameters set by both the Boot Monitor and the X server (that is X server defaults or the changes you make using the X server configuration methods described in Chapter 6, Terminal Configuration Methods). The server-only portion is used by X server configuration methods to write parameters that can be saved in NVRAM.

You should not attempt to change data set automatically by the Boot Monitor. You can change other parameters; see the following cautionary note.

If a remote configuration parameter is listed in the description column, you can set the parameter using the NVRAM utility or X server configuration utilities. A subset of the booting parameters can also be set using the Boot Monitor Setup menus described in "Using Boot Monitor Setup Menus to Configure Terminals".

CAUTION:

Do not change the contents of NVRAM using the NVRAM utility unless you know how your changes will affect the terminal. Incorrect NVRAM settings can seriously impair the terminal's operation. Do not change settings in reserved areas or parameters set automatically by the Boot Monitor.

Table 11-7 Shared NVRAM Version 4