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Open Firmware, or OpenBoot in Sun Microsystems parlance, is a standard defining the interfaces of a computer firmware system, formerly endorsed by the Institute of Electrical and Electronics Engineers (IEEE). It originated at Sun, and has been used by Sun, Apple, IBM, ARM〔(Building Open Firmware for ARM )〕 and most other non-x86 PCI chipset vendors. Open Firmware allows the system to load platform-independent drivers directly from the PCI card, improving compatibility. Open Firmware may be accessed through its Forth language shell interface. It achieves essentially the same functionality as the later EFI standard initiated at Intel, with lower overhead . Open Firmware is 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which was not reaffirmed by the Open Firmware Working Group (OFWG) since 1998 and has therefore been officially withdrawn by IEEE. 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. Sun's implementation is available under a BSD license.〔(【引用サイトリンク】url=http://www.openfirmware.info/Welcome_to_OpenBIOS )〕 == Advantages == Open Firmware Forth Code may be compiled into FCode, a bytecode which is independent of computer architecture details such as the instruction set and memory hierarchy. A PCI card may include a program, compiled to FCode, which runs on any Open Firmware system. In this way, it can provide platform-independent boot-time diagnostics, configuration code, and device drivers. FCode is also very compact, so that a disk driver may require only one or two kilobytes. Therefore, many of the same I/O cards can be used on Sun systems and Macintoshes that used Open Firmware. FCode implements ANS Forth and a subset of the Open Firmware library. Open Firmware furthermore defines a standard way to describe the hardware of a system. This helps the operating system to better understand its host computer, relying less on user configuration and hardware polling. Being based upon an interactive programming language, Open Firmware can be used to efficiently test and bring up new hardware. It allows drivers to be written and tested interactively. Operational video and mouse drivers are the only prerequisite for a graphical interface suitable for end-user diagnostics. Indeed, Apple shipped such a diagnostic "operating system" in many Power Macintoshes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Open Firmware」の詳細全文を読む スポンサード リンク
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