computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, ...

, the System Management BIOS (SMBIOS) specification defines

data structure In computer science, a data structure is a data organization, management, and storage format that is usually chosen for efficient access to data. More precisely, a data structure is a collection of data values, the relationships among them, ...

s (and access methods) that can be used to read management information produced by the

BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the b ...

of a

computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These prog ...

. This eliminates the need for the

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

to probe hardware directly to discover what devices are present in the computer. The SMBIOS specification is produced by the

Distributed Management Task Force Distributed Management Task Force (DMTF) is a 501(c)(6) nonprofit industry standards organization that creates open manageability standards spanning diverse emerging and traditional IT infrastructures including cloud, virtualization, network, s ...

(DMTF), a non-profit

standards development organization A standards organization, standards body, standards developing organization (SDO), or standards setting organization (SSO) is an organization whose primary function is developing, coordinating, promulgating, revising, amending, reissuing, interpr ...

. The DMTF estimates that two billion client and server systems implement SMBIOS. The DMTF released the version 3.6.0 of the specification on June 20, 2022. SMBIOS was originally known as Desktop Management BIOS (DMIBIOS), since it interacted with the

Desktop Management Interface The Desktop Management Interface (DMI) generates a standard framework for managing and tracking components in a desktop, notebook or server computer, by abstracting these components from the software that manages them. The development of DMI, 2. ...

(DMI).

History

Version 1 of the Desktop Management BIOS (DMIBIOS) specification was produced by

Phoenix Technologies Phoenix Technologies Ltd is an American company that designs, develops and supports core system software for personal computers and other computing devices. The company's products commonly referred to as BIOS (Basic Input/Output System) or firm ...

in or before 1996. Version 2.0 of the Desktop Management BIOS specification was released on March 6, 1996 by

American Megatrends AMI (American Megatrends International LLC, formerly American Megatrends Inc.) is an international hardware and software company, specializing in PC hardware and firmware. The company was founded in 1985 by Pat Sarma and Subramonian Shankar. I ...

(AMI),

Award Software Award Software International Inc. was a BIOS manufacturer founded in 1983, by Rene Vishney and Bob Stillman in San Jose, California. In 1984 the company moved its international headquarters to Los Gatos, California, United States. History In 1 ...

Dell Dell is an American based technology company. It develops, sells, repairs, and supports computers and related products and services. Dell is owned by its parent company, Dell Technologies. Dell sells personal computers (PCs), servers, data ...

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 ser ...

, Phoenix Technologies, and

SystemSoft Corporation Insyde Software () is a company that specializes in UEFI system firmware and engineering support services, primarily for OEM and ODM computer and component device manufacturers. They are listed on the Gre Tai Market of Taiwan and headquartered i ...

. It introduced 16-bit plug-and-play functions used to access the structures from Windows 95. The last version to be published directly by vendors was 2.3 on August 12, 1998. The authors were American Megatrends, Award Software,

Compaq Compaq Computer Corporation (sometimes abbreviated to CQ prior to a 2007 rebranding) was an American information technology company founded in 1982 that developed, sold, and supported computers and related products and services. Compaq produced ...

, Dell,

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...

, Intel, International Business Machines (IBM), Phoenix Technologies, and SystemSoft Corporation. Circa 1999, the

(DMTF) took ownership of the specification. The first version published by the DMTF was 2.3.1 on March 16, 1999. At approximately the same time

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washi ...

started to require that OEMs and BIOS vendors support the interface/data-set in order to have Microsoft

certification Certification is the provision by an independent body of written assurance (a certificate) that the product, service or system in question meets specific requirements. It is the formal attestation or confirmation of certain characteristics of a ...

. Version 3.0.0, introduced in February 2015, added a 64-bit entry point, which can coexist with the previously defined 32-bit entry point. Version 3.4.0 was released in August 2020. Version 3.5.0 was released in September 2021. Version 3.6.0 was released in June 2022.

The SMBIOS table consists of an entry point (two types are defined, 32-bit and 64-bit), and a variable number of structures that describe platform components and features. These structures are occasionally referred to as "tables" or "records" in third-party documentation.

Structure types

As of version 3.3.0, the SMBIOS specification defines the following structure types:

Accessing SMBIOS data

The EFI configuration table (EFI_CONFIGURATION_TABLE) contains entries pointing to the SMBIOS 2 and/or SMBIOS 3 tables. There are several ways to access the data, depending on the platform and operating system.

From UEFI

In the UEFI Shell, the command can retrieve and display the SMBIOS data. One can often enter the UEFI shell by entering the system firmware settings, and then selecting the shell as a boot option (as opposed to a DVD drive or hard drive).

From Unix

For

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whi ...

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

, etc., the

dmidecode dmidecode is a free userspace command-line utility for Linux that can parse the SMBIOS data. The name dmidecode is derived from Desktop Management Interface, a related standard with which dmidecode originally interfaced. SMBIOS was originally n ...

utility can be used.

From Windows

specifies WMI as the preferred mechanism for accessing SMBIOS information from

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...

. On Windows systems that support it (XP and later), some SMBIOS information can be viewed with either the

WMIC WMIC (660 AM) is a full service radio station licensed to Sandusky, Michigan at 660 kHz on the AM dial, with an power output of 1,000 watts. WMIC covers Sanilac County, Michigan and The Thumb area of Michigan. The station is owned by San ...

utility with 'BIOS'/'MEMORYCHIP'/'BASEBOARD' and similar parameters, or by looking in the Windows Registry under HKLM\HARDWARE\DESCRIPTION\System. Various software utilities can retrieve raw SMBIOS data, including FirmwareTablesView and

AIDA64 AIDA64 is a system information, diagnostics, and auditing application developed by FinalWire Ltd (a Hungarian company) that runs on Windows, Android, iOS, Windows Phone, Tizen, ChromeOS and Sailfish OS operating systems. It displays detailed in ...

Generating SMBIOS data

Table and structure creation is normally up to the system firmware/BIOS. The

UEFI Platform Initialization The Platform Initialization Specification (PI Specification) is a specification published by the Unified EFI Forum that describes the internal interfaces between different parts of computer platform firmware. This allows for more interoperabili ...

(PI) specification includes an SMBIOS protocol (EFI_SMBIOS_PROTOCOL) that allows components to submit SMBIOS structures for inclusion, and enables the producer to create the SMBIOS table for a platform.

Platform virtualization software Platform virtualization software, specifically emulators and hypervisors, are software packages that emulate the whole physical computer machine, often providing multiple virtual machines on one physical platform. The table below compares basic i ...

can also generate SMBIOS tables for use inside VMs, for instance

QEMU QEMU is a free and open-source emulator (Quick EMUlator). It emulates the machine's central processing unit, processor through dynamic binary translation and provides a set of different hardware and device models for the machine, enabling it t ...

. If the SMBIOS data is not generated and filled correctly then the machine may behave unexpectedly. For example, a

Mini PC A nettop (or miniature PC, Mini PC or Smart Micro PC) is a small-sized, inexpensive, low-power, legacy-free desktop computer designed for basic tasks such as web browsing, accessing web-based applications, document processing, and audio/video ...

that advertises ''Chassis Information , Type = Tablet'' may behave unexpectedly using Linux. A desktop manager like

GNOME A gnome is a mythological creature and diminutive spirit in Renaissance magic and alchemy, first introduced by Paracelsus in the 16th century and later adopted by more recent authors including those of modern fantasy literature. Its characte ...

will attempt to monitor a non-existent battery and shut down the screen and network interfaces when the missing battery drops below a threshold. Additionally, if the ''Chassis Information , Manufacturer'' is not filled in correctly then work-arounds for the incorrect ''Type = Tablet'' problem cannot be applied.

References

External links

*
SMBIOS Demystified
August 1, 2006, by Kiran Sanjeeva {{DMTF Standards DMTF standards BIOS Computer hardware standards