OpenBoot 2.x Command Reference Manual

Common Failures

This section describes some common failures and how you can fix them.

Blank Screen - No Output

Problem: Your system screen is blank and does not show any output.

Here are possible causes for this problem:

Hardware has failed.

Refer to your system documentation.

Keyboard is not attached.

If the keyboard is not plugged in, the output goes to TTYA instead. To fix this problem, power the system down, plug the keyboard in, and power on again.

Monitor is not turned on or plugged in.

Check the power cable on the monitor. Make sure the monitor cable is plugged into the system frame buffer; then turn the monitor on.

output-device is set to TTYA or TTYB.

This means the NVRAM parameter output-device is set to ttya or ttyb instead of being set to screen. You can do one of the following:

Power the system down. Then turn it on, and immediately press Stop-N. This sets all NVRAM parameters to their default values. As a result, the output-device parameter is set to screen. Be warned that all previous non-default settings are reset to their default values as well. You must restore them as needed.

Connect a terminal to TTYA and reset the system. After getting to the ok prompt on the terminal, type: screen output to send output to the frame buffer. Use setenv to change the default display device, if needed.

System has multiple frame buffers.

If your system has several plugged-in frame buffers, or it has one built-in frame buffer and one or more plugged in, then it is possible that the wrong frame buffer is being used as the console device. See "Setting the Console to a Specific Monitor".

System Boots From the Wrong Device

Problem: Your system is supposed to boot from the disk; instead, it boots from the net.

There are two possible causes for this:

The diag-switch? NVRAM parameter is inadvertently set to true.

Interrupt the booting process with Stop-A. Type the following commands at the ok prompt:

ok setenv diag-switch? false 
ok boot

The system should now start booting from the disk.

The boot-device NVRAM parameter is set to net instead of disk.

Interrupt the booting process with Stop-A. Type the following commands at the ok prompt:

ok setenv boot-device disk 
ok boot

Note that the preceding commands cause the system to boot from the disk defined as disk (target 3) in the device aliases list. If you want to boot from disk1 (target 1), disk2 (target 2), or disk3 (target 3), set boot-device accordingly.

Problem: Your system is booting from a disk instead of from the net.

boot-device is not set to net.

Interrupt the booting process with Stop-A. Type the following commands at the ok prompt:

ok setenv boot-device net 
ok boot

Problem: Your system is booting from the wrong disk. (For example, you have more than one disk in your system. You want the system to boot from disk2, but the system is booting from disk1 instead.)

boot-device is not set to the correct disk.

Interrupt the booting process with Stop-A. Type the following commands at the ok prompt:

ok setenv boot-device disk2 
ok boot

System Will Not Boot From Ethernet

Problem: Your system fails to boot from the net.

The problem could be one of the following:

NIS maps are out of date.

Report the problem to your system administrator.

Ethernet cable is not plugged in.

Plug in the ethernet cable. The system should continue with the booting process.

Server is not responding: no carrier messages.

Report the problem to your system administrator.

tpe-link-test is disabled.

Refer to the troubleshooting information in your system documentation. (Note: systems that do not have Twisted Pair Ethernet will not have the tpe-link-test parameter.)

System Will Not Boot From Disk

Problem: You are booting from a disk and the system fails with the message:The file just loaded does not appear to be executable.

The boot block is missing or corrupted.

Install a new boot block.

Problem: You are booting from a disk and the system fails with the message: Can't open boot device.

The disk may be powered down (especially if it is an external disk).

Turn on power to the disk, and make sure the SCSI cable is connected to the disk and the system.

SCSI Problems

Problem: Your system has more than one disk installed, and you get SCSI-related errors.

Your system might have duplicate SCSI target number settings.

Try the following procedure:

Unplug all but one of the disks.

At the ok prompt, type:
```
ok probe-scsi-all 
```
Note the target number and its corresponding unit number.

Plug in another disk and perform step b again.

If you get an error, change the target number of this disk to be one of the unused target numbers.

Repeat steps b, c, and d until all the disks are plugged back in.

Setting the Console to a Specific Monitor

Problem: You have more than one monitor attached to the system, and the console is not set to an intended monitor.

If you have more than one monitor attached to the system, the OpenBoot firmware always assigns the console to the frame buffer specified by the output-device NVRAM parameter. The default value of output-device is screen, which is an alias for the first frame buffer that the firmware finds in the system.

A common way to change this default is to change output-device to the appropriate frame buffer:

ok nvalias myscreen /obio/cgfourteen
ok setenv output-device myscreen 
ok reset

Another way of setting the console to a specific monitor is to change the sbus-probe-list NVRAM parameter.

ok show sbus-probe-list     (
Display the current and default values)
sbus-probe-list f0123 f0123     (Your system may have
a different number of SBus slots)
ok

If the frame buffer that you are choosing as the console is in slot 2, change sbus-probe-list to probe slot 2 first:

ok setenv sbus-probe-list 23f01
ok reset