Testing System Hardware

The test command is used to test specific hardware devices, such as the loopback network device. This device could be tested by using the following command:

 ok test net Internal Loopback test - (OK) External Loopback test - (OK) 

This indicates that the loopback device is operating correctly. Alternatively, the watch-clock command is used to test the clock device:

 ok watch-clock Watching the 'seconds' register of the real time clock chip.  It should be ticking once a second.  Type any key to stop. 1 2 3 

Tip  

Timing results can be cross-checked against a reliable timing device for accuracy.

If the system is meant to boot across the network, but a boot attempt does not succeed, it is possible to test network connectivity using the watch-net program. This determines whether or not the system s primary network interface is able to read packets from the network it is connected to. The output from the watch-net program looks like this:

 Internal Loopback test - succeeded External Loopback test - succeeded Looking for Ethernet packets. '.' is a good packet. 'X' is a bad packet. Type any key to stop ......X.........XXXX......XX............ 

In this case, a number of packets are marked as bad, even though the system has been connected successfully to the network.

In addition to the watch-net command, the OpenBoot monitor can perform a number of other diagnostic tests. For example, all of the SCSI devices attached to the system can be detected by using the probe-scsi command. The probe-scsi command displays all of the SCSI devices attached to the system. The output of probe-scsi looks like this:

 ok probe-scsi Target 1 Unit 0 Disk SUN0104 Copyright (C) 1995 Sun Microsystems All rights reserved Target 1 Unit 0 Disk SUN0207 Copyright (C) 1995 Sun Microsystems All rights reserved 

Here, we can see that two SCSI disks have been detected. If any other disks or SCSI devices were attached to the chain, they have not been detected, indicating a misconfiguration or hardware error.

Tip  

If you are using a PCI system, then SCSI devices may or may not appear.