SRM firmware

Last updated
A screenshot of SRM loading aboot (a Linux bootloader) SRM loading aboot.png
A screenshot of SRM loading aboot (a Linux bootloader)

The SRM firmware (also called the SRM console) is the boot firmware written by Digital Equipment Corporation (DEC) for computer systems based on the DEC Alpha microprocessor. SRM are the initials of (Alpha) System Reference Manual, the publication detailing the Alpha AXP architecture and which specified various features of the SRM firmware.

The SRM console was initially designed to boot DEC's OSF/1 AXP (later called Digital UNIX and finally Tru64 UNIX) and OpenVMS operating systems, although various other operating systems (such as Linux, NetBSD, OpenBSD, and FreeBSD, for example) were also written to boot from the SRM console. The third proprietary operating system published for the Alpha AXP architecture – Microsoft Windows NT – did not boot from SRM; instead, Windows booted from the ARC (multi platform "Advanced RISC Computing") boot firmware. (ARC is also known as AlphaBIOS.)

On many Alpha computer systems – for example, the Digital Personal Workstation – both SRM and ARC could be loaded onto the EEPROM which held the boot firmware. However, on some smaller systems (or large systems which were never intended to boot Windows), only one of the two boot firmware variants could fit onto the EEPROM at one time. For example, the flash EEPROM of certain models of the DEC Multia, which was a small, personal Alpha AXP workstation designed to run Windows NT, was only large enough to hold a single firmware.

The SRM console is capable of display on either a graphical adapter (such as a PCI VGA card) or, if no graphical console and/or local keyboard is detected, on a serial connection to a VT100-compatible terminal. In this way the SRM console is similar to the Open Firmware used in SPARC and Apple PowerMac computers, for example.

Upon system initialization, an Alpha AXP computer set to boot from the SRM console displays a short report of the software version of the firmware, and presents the "three chevron prompt" consisting of three greater-than signs:

Digital Personal WorkStation 433au Console V7.2-1 Mar  6 2000 14:47:02 >>>

Several commands are available by typing them at the prompt, and a list of possible commands is available by entering the command help or man at the prompt. Various system variables for establishing automatic boot settings, parameter strings to be passed to an operating system and the like may also be set from the SRM prompt. The SRM firmware contains drivers for booting from boot media including SCSI hard disks and CD-ROM drives attached to a supported SCSI adapter, various IDE ATA and ATAPI devices, and network booting via BOOTP or DHCP is possible with supported network adapters.

When an appropriate disk boot device is available, the SRM console locates and loads the target primary bootstrap image using information written in the target disk boot block; in logical block zero. The boot block contains the disk location and block size of the target primary bootstrap image file, and SRM will load that into memory and will then transfer control to it.

Related Research Articles

<span class="mw-page-title-main">BIOS</span> Firmware for hardware initialization and OS runtime services

In computing, BIOS is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process. The BIOS firmware comes pre-installed on an IBM PC or IBM PC compatible's system board and exists in some UEFI-based systems too as a compatibly support module to maintain compatibility operating systems that do not support UEFI native operation. The name originates from the Basic Input/Output System used in the CP/M operating system in 1975. The BIOS originally proprietary to the IBM PC has been reverse engineered by some companies looking to create compatible systems. The interface of that original system serves as a de facto standard.

<span class="mw-page-title-main">DEC Alpha</span> 64-bit RISC instruction set architecture

Alpha is a 64-bit reduced instruction set computer (RISC) instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). Alpha was designed to replace 32-bit VAX complex instruction set computers (CISC) and to be a highly competitive RISC processor for Unix workstations and similar markets.

<span class="mw-page-title-main">Tru64 UNIX</span> Computer operating system

Tru64 UNIX is a discontinued 64-bit UNIX operating system for the Alpha instruction set architecture (ISA), currently owned by Hewlett-Packard (HP). Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation (DEC), where it was known as Digital UNIX.

<span class="mw-page-title-main">Booting</span> Process of starting a computer

In computing, booting is the process of starting a computer as initiated via hardware such as a button or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so some process must load software into memory before it can be executed. This may be done by hardware or firmware in the CPU, or by a separate processor in the computer system.

<span class="mw-page-title-main">Ultrix</span> Series of discontinued Unix operating systems by DEC

Ultrix is the brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX, MicroVAX and DECstations.

<span class="mw-page-title-main">DECstation</span> DEC brand of computers

The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a range of PC compatibles. The MIPS-based workstations ran ULTRIX, a DEC-proprietary version of UNIX, and early releases of OSF/1.

<span class="mw-page-title-main">RISC iX</span> Discontinued Unix operating system

RISC iX is a discontinued Unix operating system designed to run on a series of workstations based on the Acorn Archimedes microcomputer. Heavily based on 4.3BSD, it was initially completed in 1988, a year after Arthur but before RISC OS. It was introduced in the ARM2-based R140 workstation in 1989, followed up by the ARM3-based R200-series workstations in 1990.

The Advanced Computing Environment (ACE) was defined by an industry consortium in the early 1990s to be the next generation commodity computing platform, the successor to personal computers based on Intel's 32-bit instruction set architecture. The effort found little support in the market and dissolved due to infighting within the group and a lack of sales.

The MIPS Magnum was a line of computer workstations designed by MIPS Computer Systems, Inc. and based on the MIPS series of RISC microprocessors. The first Magnum was released in March, 1990, and production of various models continued until 1993 when SGI bought MIPS Technologies. SGI cancelled the MIPS Magnum line to promote their own workstations including the entry-level SGI Indy.

The NEC RISCstation was a line of computer workstations made by NEC in the mid-1990s, based on MIPS RISC microprocessors and designed to run Microsoft Windows NT. A series of nearly identical machines were also sold by NEC in headless configuration as the RISCserver series, and were intended for use as Windows NT workgroup servers.

Advanced RISC Computing (ARC) is a specification promulgated by a defunct consortium of computer manufacturers, setting forth a standard MIPS RISC-based computer hardware and firmware environment. The firmware is also known as AlphaBIOS.

The Multia, later re-branded the Universal Desktop Box, was a line of desktop computers introduced by Digital Equipment Corporation on 7 November 1994. The line is notable in that units were offered with either an Alpha AXP or Intel Pentium processor as the CPU, and most hardware other than the backplane and CPU were interchangeable. Both the Alpha and Intel versions were intended to run Windows NT.

ntdetect.com is a component of Microsoft Windows NT-based operating systems that operate on the x86 architecture. It is used during the Windows NT startup process, and is responsible for detecting basic hardware that will be required to start the operating system.

In BSD-derived computer operating systems and in related operating systems such as SunOS, a disklabel is a record stored on a data storage device such as a hard disk that contains information about the location of the partitions on the disk. Disklabels were introduced in the 4.3BSD-Tahoe release. Disklabels are usually edited using the disklabel utility. In later versions of FreeBSD, this was renamed as bsdlabel.

<span class="mw-page-title-main">AlphaStation</span>

AlphaStation is the name given to a series of computer workstations, produced from 1994 onwards by Digital Equipment Corporation, and later by Compaq and HP. As the name suggests, the AlphaStations were based on the DEC Alpha 64-bit microprocessor. Supported operating systems for AlphaStations comprise Tru64 UNIX, OpenVMS and Windows NT. Most of these workstations can also run various versions of Linux and BSD operating systems.

<span class="mw-page-title-main">DEC 3000 AXP</span>

DEC 3000 AXP was the name given to a series of computer workstations and servers, produced from 1992 to around 1995 by Digital Equipment Corporation. The DEC 3000 AXP series formed part of the first generation of computer systems based on the 64-bit Alpha AXP architecture. Supported operating systems for the DEC 3000 AXP series were DEC OSF/1 AXP and OpenVMS AXP.

PALcode is the name used by DEC in the Alpha instruction set architecture (ISA) for a set of functions in the System Reference Manual (SRM) or AlphaBIOS firmware, providing a hardware abstraction layer for system software, covering features such as cache management, translation lookaside buffer (TLB) miss handling, interrupt handling, and exception handling. It evolved from a feature of the DEC PRISM architecture named Epicode.

The DECpc AXP 150, code-named Jensen, is an entry-level workstation developed and manufactured by Digital Equipment Corporation. Introduced on 25 May 1993, the DECpc AXP 150 was the first Alpha-based system to support the Windows NT operating system and the basis for the DEC 2000 AXP entry-level servers. It was discontinued on 28 February 1994, succeeded by the entry-level Multia and the entry-level and mid-range models of the AlphaStation family. The charter for the development and production of the DEC 2000 AXP was held by Digital's Entry Level Solutions Business, based in Ayr, Scotland.

The DEC 7000 AXP and DEC 10000 AXP are a series of high-end multiprocessor server computers developed and manufactured by Digital Equipment Corporation, introduced on 10 November 1992. These systems formed part of the first generation of systems based on the 64-bit Alpha AXP architecture and at the time of introduction, ran Digital's OpenVMS AXP operating system, with DEC OSF/1 AXP available in March 1993. They were designed in parallel with the VAX 7000 and VAX 10000 minicomputers, and are identical except for the processor module(s) and supported bus interfaces. A field upgrade from a VAX 7000/10000 to a DEC 7000/10000 AXP was possible by means of swapping the processor boards.

The Digital Personal Workstation, code named "sports car", is a family of entry-level to mid-range workstation computers developed and manufactured by Digital Equipment Corporation (DEC). These workstations are based on the DEC Alpha and Intel Pentium Pro or Pentium II microprocessors. Members of this family can run the Digital UNIX, OpenVMS, and Windows NT operating systems. The i-Series, based on Pentium Pro, was introduced first, on September 23, 1996.