Open Firmware (also,
OpenBoot) is a hardware-independent
firmware (
computer software which loads the
operating system), developed by Mitch Bradley at
Sun Microsystems, and used in post-
NuBus PowerPC-based
Apple Macintosh computers,
Sun Microsystems SPARC based workstations and servers,
IBM POWER systems,
Pegasos systems, and the laptop designed by
OLPC among others. It is available under a
BSD license.
[1] The proposed
Power Architecture Platform Reference will also be Open Firmware based. Open Firmware is accessed via a
Forth-based
shell interface and fulfills many of the same tasks as
BIOS does on
PC computers, although Open Firmware is considerably more powerful than BIOS. For example, due to the power of Forth (a high-level languge), it is possible to program Open Firmware to solve the
Tower of Hanoi problem.
[2]
Open Firmware (or "OF") was described by
IEEE standard
IEEE 1275-1994, which was not reaffirmed by the Open Firmware Working Group (OFWG) since 1998 and has therefore been officially withdrawn by IEEE. This means it is unavailable from the IEEE, but the last text is available from the Forth research project at the Institute of Computer Languages,
Vienna University of Technology in Austria.
Several commercial implementations of Open Firmware have been released to the Open Source community in 2006, including SUN OpenBOOT, Firmworks OpenFirmware and Codegen SmartFirmware. The source code is available from the
OpenBIOS project.
Advantages
Because the Open Firmware Forth code is compiled into
FCode (a bytecode) and not into the
machine language of any particular
computer architecture, Open Firmware code included in, say, an I/O card can be executed by any system that uses Open Firmware. In this way, an I/O card can provide boot-time
diagnostics, configuration code, and
device drivers that will be usable on any system running Open Firmware, allowing many of the same I/O cards to be used on Sun systems and Macintoshes.
Being based upon an interactive programming language, Open Firmware can be used to quickly test and bring up new hardware.
Access
On Sun systems, the Open Firmware interface is displayed on the console terminal before the bootstrapping of the system software. If a keyboard is connected, the main video display will be used as the console terminal and Open Firmware can be re-entered at any time by pressing
Stop-A (
L1-A) on the keyboard. If no keyboard is connected, then the first serial line on the system is usually used as the console and Open Firmware is re-entered by sending a "Break" on the serial line. While the system software is running, various Open Firmware settings can be read or written using the
eeprom command.
On a PowerPC-based
[3] Macintosh, the Open Firmware interface can be accessed by pressing the keys
Cmd-Option-O-F at startup. This functionality is generally only used by developers or troubleshooting I.T. personnel; for common users, the
Mac OS X operating system provides a high level
graphical user interface to change commonly used Open Firmware settings. For instance, it is possible to specify the
boot disk or
partition without directly using the Open Firmware interface. Other Open Firmware settings can be changed using the
nvram command while the system software is running.
On
Pegasos, simply press
Esc at startup.
On
IBM POWER systems, Open Firmware ("ok" prompt) can be accessed through the SMS Boot Menu. SMS Boot Menu can be accessed by pressing "1" or "F1" during the boot sequence, after hardware checking, and just before the OS boot.
See also
External links
Notes and references
firmware is a computer program that is embedded in a hardware device, for example a microcontroller. It can also be provided on flash ROMs or as a binary image file that can be uploaded onto existing hardware by a user.
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Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some task on a computer system. [1]
..... Click the link for more information.
An operating system (OS) is the software that manages the sharing of the resources of a computer. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the
..... Click the link for more information.
Sun Microsystems
Public (NASDAQ: JAVA )
Founded 1982
Headquarters Santa Clara, California, United States
Key people Scott McNealy, Chairman
Jonathan I.
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NuBus is a 32-bit parallel computer bus, originally developed at MIT as a part of the NuMachine workstation project, and eventually used by Apple Computer, NeXT and Texas Instruments. It is no longer widely used outside of the embedded market.
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PowerPC is a RISC microprocessor architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM. Originally intended for personal computers, PowerPC CPUs have since become popular embedded and high-performance processors as well.
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Macintosh, commonly known as Mac, is a brand name which covers several lines of personal computers designed, developed, and marketed by Apple Inc. Named after the McIntosh variety of apple, the original Macintosh was released on January 24, 1984.
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Sun Microsystems
Public (NASDAQ: JAVA )
Founded 1982
Headquarters Santa Clara, California, United States
Key people Scott McNealy, Chairman
Jonathan I.
..... Click the link for more information.
SPARC (Scalable Processor ARChitecture) is a RISC microprocessor instruction set architecture originally designed in 1985 by Sun Microsystems.
SPARC is a registered trademark of SPARC International, Inc.
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International Business Machines Corporation
Public (NYSE: IBM )
Founded 1889, incorporated 1911
Headquarters Armonk, New York, USA
Key people Samuel J.
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POWER is a RISC instruction set architecture designed by IBM. The name is a backronym for Performance Optimization With Enhanced RISC.
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- The present article is about the Pegasos computer platform. Pegasos may also refer to the horse Pegasus from Greek mythology.
Pegasos..... Click the link for more information. One Laptop per Child
Formation January 2005
Type Non-profit
Headquarters Delaware
Location Boston
Chairman Nicholas Negroponte
Key people Mary Lou Jepsen, Walter Bender, Jim Gettys, Seymour Papert, Alan Kay
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"New" BSD License
Author: Regents of the University of California
Version: N/A
Copyright on the license: Public Domain
Publication date: ?
OSI approved: Yes
Debian approved: Yes
Free Software: Yes
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Power Architecture Platform Reference (PAPR) is an initiative from Power.org to make a new open computing platform based on Power Architecture technology. It follows two previous attempts, PReP and CHRP in the 1990's.
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Forth
Paradigm: Procedural, stack-oriented
Appeared in: 1970s
Designed by: Charles H. Moore
Typing discipline: typeless
Major implementations: Forth, Inc.
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command line interpreter (also command line shell, command language interpreter) is a computer program that reads lines of text entered by a user and interprets them in the context of a given operating system or programming language.
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Bios or
BIOS may refer to:
- Life (in Greek, βίος/Bios)
- Biographies, a genre of literature/media based on accounts of people's lives
..... Click the link for more information. personal computer (PC) is a computer whose original sales price, size, and capabilities make it useful for individuals.
It is unknown who coined the phrase with the intent of a small affordable computing device but John W.
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Tower of Hanoi puzzle for T(4,3).]]
The Tower of Hanoi or Towers of Hanoi is a mathematical game or puzzle. It consists of three pegs, and a number of disks of different sizes which can slide onto any peg.
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Institute of Electrical and Electronics Engineers
Type Professional Organization
Founded January 1, 1963
Origins Merger of the American Institute of Electrical Engineers and the Institute of Radio Engineers
Key people Leah H.
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Vienna University of Technology is one of the major universities in Vienna, the capital of Austria. Founded in 1815 as the "Imperial-Royal Polytechnic Institute" (k. k.
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OpenBIOS is a project aiming to provide free and open source implementations of Open Firmware. It is also the name of such an implementation.
Most of the implementations provide by OpenBIOS rely on an additional lower-level firmware for hardware initialization, such as
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FCode is a Forth programming language dialect compliant with ANS Forth. It is of interest mainly for its use in Open Firmware. It can exist in two forms; source code and a compiled version, known as bytecode.
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Machine code or machine language is a system of instructions and data directly executed by a computer's central processing unit. Machine code is the lowest-level of abstraction for representing a computer program.
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computer architecture is the conceptual design and fundamental operational structure of a computer system. It is a blueprint and functional description of requirements (especially speeds and interconnections) and design implementations for the various parts of a computer —
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In general, diagnosis (plural diagnoses) has two distinct dictionary definitions. The first definition is "the recognition of a disease or condition by its outward signs and symptoms", while the second definition is "the analysis of the underlying physiological/biochemical
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A device driver, or software driver is a computer program allowing higher-level computer programs to interact with a computer hardware device.
A driver typically communicates with the device through the computer bus or communications subsystem to which the hardware is
..... Click the link for more information.
Mac OS X (IPA: /mæk.oʊ.ɛs.tɛn/) is a line of graphical operating systems developed, marketed, and sold by Apple Inc., the latest of which is pre-loaded on all currently shipping Macintosh computers.
..... Click the link for more information.
An operating system (OS) is the software that manages the sharing of the resources of a computer. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the
..... Click the link for more information.