Sun Microsystems SPARCstation 4 110 Service Manual page 29

Note – At any point during the high-level OBP execution, you can abort the OBP
sequence and access the FORTH Monitor by pressing the Stop and "a" keys
simultaneously.
NVRAM Parameters Used During POST and Boot Sequence
TABLE 2-1
NVRAM Parameter
selftest-#megs
Default = 1
diag-switch?
Default = false
auto-boot?
Default = true
At the FORTH Monitor prompt, you can direct the system to boot the operating
system from a location that you specify, or you can execute a variety of additional
FORTH-based tests. See the OpenBoot Command Reference for a complete description
of the FORTH Monitor.
Description
This parameter determines how many megabytes of
memory to test during high-level OBP testing if diag-
switch? is concurrently set to false. The minimum is
zero; the maximum is the amount actually installed in the
system. The default is a 1-megabyte test.
When set to true, this parameter forces the system to test
automatically all available memory. It also enables
diagnostic message output to serial port A. If a properly
configured terminal or "tip window" is connected,
diagnostic progress can be monitored through serial port A.
When auto-boot? is set to true and diag-switch? is set
to false, diag-switch? forces the system to boot from the
device and file specified in boot-dev and boot-file.
If auto-boot? is set to true and diag-switch? is set to
true, the system boots the operating system from the
device and file specified in the diag-device and diag-
file NVRAM parameter fields. When set to false, this
will suppress the boot sequence. The system halts with the
ok prompt.
Chapter 2 Troubleshooting Overview 2-5