Executing Boot PROM Commands 2232021 1 Boot PROM

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Executing Boot PROM Commands 2/23/2021 1

Executing Boot PROM Commands 2/23/2021 1

Boot PROM Fundamentals �All Sun systems have resident boot PROM firmware �Provides basic hardware

Boot PROM Fundamentals �All Sun systems have resident boot PROM firmware �Provides basic hardware testing and initialization prior to booting �Enables to boot from wide range of devices �Has access to a standard set of generic device drivers 2/23/2021 2

Goal of the Open. Boot Architecture Standard �Goal of IEEE standard for the Open.

Goal of the Open. Boot Architecture Standard �Goal of IEEE standard for the Open. Boot Architecture �Test and initialize system hardware �Determine the system’s hardware configuration �Boot the Operating Environment �Provide an interactive interface for configuration, testing, and debugging �Enable the use of third-party devices 2/23/2021 3

Boot PROM �Each system has a boot PROM chip � 1 Mbyte chip is

Boot PROM �Each system has a boot PROM chip � 1 Mbyte chip is typically located on the same board as the CPU �Boot PROM chips are usually found in a pluggable socket on older systems �As of 3. x PROM, they are permanently soldered to the main system board 2/23/2021 4

�The Ultra workstations use a reprogrammable boot PROM called Flash PROM (FPROM) �Desktop systems

�The Ultra workstations use a reprogrammable boot PROM called Flash PROM (FPROM) �Desktop systems have a write-protect jumper 2/23/2021 5

�The main functions of the boot PROM are to test the system hardware and

�The main functions of the boot PROM are to test the system hardware and to boot the OE. �The boot PROM firmware is referred to as the “monitor program” �Also provides a user interface and firmware utility commands, known as the FORTH command set 2/23/2021 6

Generations of Sun boot PROM � 1. x - The first boot PROM used

Generations of Sun boot PROM � 1. x - The first boot PROM used on SPARC systems � 2. x - The first Openboot PROM � 3. x - The Openboot PROM with a flash update feature � 4. x - The Openboot PROM that supports the 64 bit Ultra. SPARC III processor � 5. x - Available on the Sun Enterprise 3500, 4500, 5500 & 6500 servers 2/23/2021 7

�To determine which version of Open. Boot PROM is running on the system �“#

�To determine which version of Open. Boot PROM is running on the system �“# /usr/platform/’uname -m’/sbin/prtdiag -v” 2/23/2021 8

NVRAM �Important hardware element �Removable chip is often located on the main system board

NVRAM �Important hardware element �Removable chip is often located on the main system board �Contains EEPROM �EEPROM stores user-configurable parameters that have been changed or customized from the boot PROM’s default parameter settings �Single lithium battery within the NVRAM module provides battery backup for the NVRAM and the clock 2/23/2021 9

�NVRAM contains editable and noneditable areas. �Non Editable areas � The Ethernet address �

�NVRAM contains editable and noneditable areas. �Non Editable areas � The Ethernet address � The system host ID �Editable areas � The time-of-day (TOD) clock value � The configuration data describing system operating parameters � A diagnostic mode switch that enables or disables POST � The device name and the path to the default boot device � A location for customized programming that is used during the boot process 2/23/2021 10

POST �When a system’s power is turned on, a low-level POST is initiated �Low-level

POST �When a system’s power is turned on, a low-level POST is initiated �Low-level POST code is stored in the boot PROM and is designed to test the basic functions of the system hardware 2/23/2021 11

�On successful completion of the low-level POST phase, the boot PROM firmware takes the

�On successful completion of the low-level POST phase, the boot PROM firmware takes the control and performs the following initialization sequence: �Probes the memory and then CPU �Probes bus devices, interprets their drivers, and builds a device tree �Installs the console 2/23/2021 12

�After the boot PROM initializes the system, the banner displays on the system console

�After the boot PROM initializes the system, the banner displays on the system console �The system checks parameters stored in the boot PROM and NVRAM determine if and how to boot the OE 2/23/2021 13

Controlling the POST phase �Stop-D key sequence �Hold down the Stop and D keys

Controlling the POST phase �Stop-D key sequence �Hold down the Stop and D keys simultaneously while system power is turned on, and the firmware automatically switches to diagnostic mode. �This mode runs extensive POST diagnostics on the system hardware. �The Open. Boot PROM variable “diag-switch? ” is set to “true” 2/23/2021 14

�Stop-N key sequence �Hold down to set the NVRAM parameters to the default values

�Stop-N key sequence �Hold down to set the NVRAM parameters to the default values �Can release the keys on seeing the LEDs on the keyboard begins to flash 2/23/2021 15

�Stop-A key sequence �To interrupt any program that is running at the time these

�Stop-A key sequence �To interrupt any program that is running at the time these keys are pressed and to put the system into the command entry mode for the Open. Boot PROM �Not recommended unless there is absolutely no alternative 2/23/2021 16

Disabling the Abort Sequence �Edit the “/etc/default/kbd” file �Remove the comment from in front

Disabling the Abort Sequence �Edit the “/etc/default/kbd” file �Remove the comment from in front of “KEYBOARD_ABORT=disable” �Save the file and execute the command “kbd -i” �When the above steps are completed the system allows Stop-A key sequence only during the boot process 2/23/2021 17

Displaying POST to the Serial Port �Can attach a terminal to the serial port

Displaying POST to the Serial Port �Can attach a terminal to the serial port of a system to capture a far greater amount of information from the POST output �When the power is turned on POST looks for a keyboard, if there is no keyboard present, POST diverts system output to serial port A 2/23/2021 18

�POST runs more extensive tests when the system is in diagnostics mode with the

�POST runs more extensive tests when the system is in diagnostics mode with the PROM parameter “diagswitch? ” set to “true” �Be sure to attach the correct type of null modem cable for your system type to serial port A 2/23/2021 19