executing boot prom

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Executing Boot PROM. Commands. 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. - PowerPoint PPT Presentation


  • Commands**

  • Boot PROM FundamentalsAll Sun systems have resident boot PROM firmwareProvides basic hardware testing and initialization prior to bootingEnables to boot from wide range of devicesHas access to a standard set of generic device drivers**

  • Goal of the OpenBoot Architecture StandardGoal of IEEE standard for the OpenBoot Architecture Test and initialize system hardwareDetermine the systems hardware configurationBoot the Operating EnvironmentProvide an interactive interface for configuration, testing, and debuggingEnable the use of third-party devices**

  • Boot PROMEach system has a boot PROM chip1 Mbyte chip is typically located on the same board as the CPUBoot PROM chips are usually found in a pluggable socket on older systemsAs of 3.x PROM, they are permanently soldered to the main system board**

  • The Ultra workstations use a reprogrammable boot PROM called Flash PROM (FPROM)Desktop systems have a write-protect jumper


  • 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 programAlso provides a user interface and firmware utility commands, known as the FORTH command set**

  • Generations of Sun boot PROM1.x - The first boot PROM used on SPARC systems2.x - The first Openboot PROM3.x - The Openboot PROM with a flash update feature4.x - The Openboot PROM that supports the 64-bit UltraSPARC III processor5.x - Available on the Sun Enterprise 3500, 4500, 5500 & 6500 servers


  • To determine which version of OpenBoot PROM is running on the system# /usr/platform/uname -m/sbin/prtdiag -v**

  • NVRAMImportant hardware element Removable chip is often located on the main system boardContains EEPROMEEPROM stores user-configurable parameters that have been changed or customized from the boot PROMs default parameter settingsSingle lithium battery within the NVRAM module provides battery backup for the NVRAM and the clock**

  • NVRAM contains editable and noneditable areas.Non Editable areasThe Ethernet addressThe system host IDEditable areasThe time-of-day (TOD) clock valueThe configuration data describing system operating parametersA diagnostic mode switch that enables or disables POSTThe device name and the path to the default boot deviceA location for customized programming that is used during the boot process**

  • POSTWhen a systems power is turned on, a low-level POST is initiatedLow-level POST code is stored in the boot PROM and is designed to test the basic functions of the system hardware**

  • 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 CPUProbes bus devices, interprets their drivers, and builds a device treeInstalls the console**

  • After the boot PROM initializes the system, the banner displays on the system consoleThe system checks parameters stored in the boot PROM and NVRAM determine if and how to boot the OE**

  • Controlling the POST phaseStop-D key sequenceHold 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 OpenBoot PROM variable diag-switch? is set to true


  • Stop-N key sequenceHold down to set the NVRAM parameters to the default valuesCan release the keys on seeing the LEDs on the keyboard begins to flash


  • Stop-A key sequenceTo 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 OpenBoot PROMNot recommended unless there is absolutely no alternative


  • Disabling the Abort SequenceEdit the /etc/default/kbd fileRemove the comment from in front of KEYBOARD_ABORT=disableSave the file and execute the command kbd -iWhen the above steps are completed the system allows Stop-A key sequence only during the boot process**

  • Displaying POST to the Serial PortCan attach a terminal to the serial port of a system to capture a far greater amount of information from the POST outputWhen the power is turned on POST looks for a keyboard, if there is no keyboard present, POST diverts system output to serial port A**

  • POST runs more extensive tests when the system is in diagnostics mode with the PROM parameter diag-switch? set to trueBe sure to attach the correct type of null modem cable for your system type to serial port A**