[Logo of Sun Microsystems]

How to Get to an OK prompt on a SPARC

Abstract:

From the beginning of reasonable UNIX Workstation Time, the Workstation typically had a physical hardware layer, a firmware layer, and an OS layer. The Firmware layer used by UNIX workstations was Open-Sourced by Sun Microsystems as OpenBoot, given to the market for vendors like IBM, Apple, etc. The FORTH based environment was called OpenFirmware by the IEEE. One such feature is to boot the operating system directly, from a pre-selected disk, in a pre-selected order. When booting from a different boot environment, like a USB stick, this can be stopped. All of this can be achieved from the OpenBoot "OK" prompt.

[Sun Microsystems Type 5 Keyboard, courtesy Deskthority]

From a Physical Console

If you are lucky enough to have a real SUN Keyboard, Video Monitor, and Mouse (KVM), breaking out to OpenBoot is easily achieved by using the following key sequence "[L1] [A]". The "[L1]" key may be labeled "Stop" on some newer keyboards, but the position is the same, so the simultaneous key sequence would be "[Stop][A]".

{0} ok

From an ILOM Console

If one is not lucky enough to have a physical console, it can be accomplished from an ILOM Console. 

T5120/user$ ssh root@SUNT4-2-ilom
Password:

Oracle(R) Integrated Lights Out Manager
Version 3.2.6.8 r128095
Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
Warning: HTTPS certificate is set to factory default.
Hostname: ORACLESP-1207BDY07F
-> 

Go Directly to OK from ILOM Console

If the system AutoBoot is not configured, the OK prompt will appear on a powered up chassis console

-> start /SP/console
Are you sure you want to start /SP/console (y/n)? y

{0} ok

Go to OK from ILOM Console & Booted OS

If the system AutoBoot is configured, the OS prompt will appear on a powered up chassis console

-> start /SP/console
Are you sure you want to start /SP/console (y/n)? y

 

sunt4-2 console login: root
password: ****

sunt4-2/root# cd / ; sync ; init 0

{0} ok

Go to OK from ILOM Console & Booted OS without root

If the system AutoBoot is configured, the OS prompt will appear on a powered up chassis console.
If there is no root password for the system and the intention is to perform a re-installation,
disable auto-boot from the ILOM and perform a reset.

-> start /SP/console
Are you sure you want to start /SP/console (y/n)? y

sunt4-2 console login: #.
Serial console stopped.

-> set /HOST/domain/control auto-boot=disable
Set 'auto-boot' to 'disable' [disabled]

-> show /HOST/domain/control

 /HOST/domain/control
    Targets:

    Properties:
        auto-boot = disabled
        boot_guests = enabled

    Commands:
        cd
        reset
        set
        show

-> reset /HOST/domain/control
Are you sure you want to reset /HOST/domain/control (y/n)? y
Performing reset on /HOST/domain/control

-> start /SP/console
Are you sure you want to start /SP/console (y/n)? y

Serial console started.  To stop, type #.

svc.startd: The system is down.
syncing file systems... done
NOTICE: Entering OpenBoot.
NOTICE: Fetching Guest MD from HV.
NOTICE: Starting additional cpus.
NOTICE: Initializing LDC services.
NOTICE: Probing PCI devices.
NOTICE: Finished PCI probing.

SPARC T4-2, No Keyboard
Copyright (c) 1998, 2018, Oracle and/or its affiliates. All rights reserved.
OpenBoot 4.38.16, 511.5000 GB memory available, Serial #99740538.
Ethernet address 0:21:28:f1:eb:7a, Host ID: 85f1eb7a.

{0} ok

Conclusions:

The SPARC Chassis, with various access methodologies, can achieve access to the OpenBoot / OpenFirmware prompt, for loading new operating systems, regardless of what was previously loaded on the chassis.