Using the Boot PROM

Using the Boot PROM
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System administrators typically use the PROM level to boot a system. You need to change the default boot device to do the following:

Add a new drive to the system either permanently or temporarily
Change the network boot strategy
Temporarily boot a stand-alone system from the network

For a complete list of PROM commands, see monitor ( 1M ) or eeprom ( 1M ) .

How to Find the PROM Revision Number for a System

Display a system's PROM revision number by using the banner command.
```
ok banner
Sun Ultra 5/10 UPA/PCI (UltraSPARC-IIi 333MHz), No Keyboard
OpenBoot 3.15, 128 MB memory installed, Serial #number.
Ethernet address number, Host ID: number.
```
Hardware configuration information, including the revision number of the PROM, is displayed. In this example, the PROM revision number is 3.15.

How to Identify Devices on a System

You might need to identify the devices on the system to determine what are the appropriate devices to boot from.

Before you can safely use the probe commands to determine what devices are attached to the system, you need to do the following:

Change the PROM auto-boot? parameter to false.
```
ok setenv auto-boot? false
```
Issue the reset-all command to clear system registers.
```
ok reset-all
```

You can view the probe commands that are available on your system by using the sifting probe command:

ok sifting probe

If you run the probe commands without clearing the system registers, the following message is displayed:

ok probe-scsi
This command may hang the system if a Stop-A or halt command
has been executed.  Please type reset-all to reset the system 
before executing this command. 
Do you wish to continue? (y/n) n

Identify the devices on the system.
```
ok probe-
device
```
(Optional) If you want the system to reboot after a power failure or after using the reset command, then reset the auto-boot? parameter to true.
```
ok setenv auto-boot? true
auto-boot? =          true
```
Boot the system back to multiuser mode.
```
ok reset
```

Example 10.1. Identifying the Devices on a System

The following example shows how to identify the devices connected to an Ultra™ 10 system.

ok setenv auto-boot? false
auto-boot? =          false
ok reset-all
Resetting ... 

Sun Ultra 5/10 UPA/PCI (UltraSPARC-IIi 333MHz), No Keyboard
OpenBoot 3.15, 128 MB memory installed, Serial #10933339.
Ethernet address 8:0:20:a6:d4:5b, Host ID: 80a6d45b.

ok probe-ide
  Device 0  ( Primary Master ) 
          ATA Model: ST34321A                                

  Device 1  ( Primary Slave ) 
         Not Present

  Device 2  ( Secondary Master ) 
         Removable ATAPI Model: CRD-8322B                               

  Device 3  ( Secondary Slave ) 
         Not Present

ok setenv auto-boot? true
auto-boot? =          true

Alternatively, you can use the devalias command to identify the device aliases and the associated paths of devices that might be connected to the system. For example:

ok devalias
screen                   /pci@1f,0/pci@1,1/SUNW,m64B@2
net                      /pci@1f,0/pci@1,1/network@1,1
cdrom                    /pci@1f,0/pci@1,1/ide@3/cdrom@2,0:f
disk                     /pci@1f,0/pci@1,1/ide@3/disk@0,0
disk3                    /pci@1f,0/pci@1,1/ide@3/disk@3,0
disk2                    /pci@1f,0/pci@1,1/ide@3/disk@2,0
disk1                    /pci@1f,0/pci@1,1/ide@3/disk@1,0
disk0                    /pci@1f,0/pci@1,1/ide@3/disk@0,0
ide                      /pci@1f,0/pci@1,1/ide@3
floppy                   /pci@1f,0/pci@1,1/ebus@1/fdthree
ttyb                     /pci@1f,0/pci@1,1/ebus@1/se:b
ttya                     /pci@1f,0/pci@1,1/ebus@1/se:a
keyboard!                /pci@1f,0/pci@1,1/ebus@1/su@14,3083f8:forcemode
keyboard                 /pci@1f,0/pci@1,1/ebus@1/su@14,3083f8
mouse                    /pci@1f,0/pci@1,1/ebus@1/su@14,3062f8
name                     aliases

How to Change the Default Boot Device

You might need to identify the devices on the system before you can change the default boot device to some other device. For information on identifying devices on the system, see How to Identify Devices on a System.

Become superuser or assume an equivalent role.

Roles contain authorizations and privileged commands. For more information about roles, see Configuring RBAC (Task Map) in System Administration Guide: Security Services .
Change to run level 0.
```
# init 0
```
The ok PROM prompt is displayed. For more information, see the init ( 1M ) man page.
Change the value of the boot-device parameter.
```
ok setenv boot-device device[n]
```
boot-device

Identifies the parameter for setting the device from which to boot.

device[n]

Identifies the boot-device value such as a disk or the network. The n can be specified as the disk number.

Use one of the probe commands if you need help identifying the disk number.
Verify that the default boot device has been changed.
```
ok printenv boot-device
```
Save the new boot-device value.
```
ok reset
```
The new boot-device value is written to the PROM.

Example 10.2. Changing the Default Boot Device

In this example, the default boot device is set to disk.

# init 0
# 
INIT: New run level: 0
.
.
.
The system is down.
syncing file systems... done
Program terminated
ok setenv boot-device disk
boot-device =         disk
ok printenv boot-device
boot-device           disk                    disk
ok reset
Sun Ultra 5/10 UPA/PCI (UltraSPARC-IIi 333MHz), No Keyboard
OpenBoot 3.15, 128 MB memory installed, Serial #number.
Ethernet address number, Host ID: number.

Boot device: disk  File and args:
SunOS Release 5.9 Version 64-bit
.
.
.
pluto console login:

In this example, the default boot device is set to the network.

# init 0
# 
INIT: New run level: 0
.
.
.
The system is down.
syncing file systems... done
Program terminated
ok setenv boot-device net
boot-device =         net
ok printenv boot-device
boot-device           net                    disk
ok reset
Sun Ultra 5/10 UPA/PCI (UltraSPARC-IIi 333MHz), No Keyboard
OpenBoot 3.15, 128 MB memory installed, Serial #number.
Ethernet address number, Host ID: number.



Boot device: net  File and args:
.
.
.
pluto console login:

How to Reset the System

Run the reset command from the ok prompt.

ok reset

This self-test program, which runs diagnostic tests on the hardware, is executed. Then, the system is rebooted.