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

, the System Management BIOS (SMBIOS) specification defines

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

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 a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...

of a

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

. This eliminates the need for the

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

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. SMBIOS was originally known as Desktop Management BIOS (DMIBIOS), since it interacted with the Desktop Management Interface (DMI). The DMTF released the version 3.7.1 of the specification on May 24, 2024.

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 fir ...

in or before 1996. Version 2.0 of the Desktop Management BIOS specification was released on March 6, 1996 by American Megatrends (AMI), Award Software,

Dell Dell Inc. is an American technology company that develops, sells, repairs, and supports personal computers (PCs), Server (computing), servers, data storage devices, network switches, software, computer peripherals including printers and webcam ...

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

, Phoenix Technologies, and SystemSoft Corporation. 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 was an American information technology, information technology company founded in 1982 that developed, sold, and supported computers and related products and services. Compaq produced some of the first IBM PC compati ...

, Dell,

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company. It was founded by Bill Hewlett and David Packard in 1939 in a one-car garage in Palo Alto, California ...

, Intel,

International Business Machines International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

(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 corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

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

certification Certification is part of testing, inspection and certification and 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 attestatio ...

. 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. Version 3.7.0 was released in July 2023.

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 ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

FreeBSD FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...

, etc., the dmidecode utility can be used.

From Windows

specifies WMI as the preferred mechanism for accessing SMBIOS information from

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

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

Generating SMBIOS data

Table and structure creation is normally up to the system firmware/BIOS. The UEFI Platform Initialization (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 can also generate SMBIOS tables for use inside VMs, for instance

QEMU The Quick Emulator (QEMU) is a free and open-source emulator that uses dynamic binary translation to emulate a computer's processor; that is, it translates the emulated binary codes to an equivalent binary format which is executed by the mach ...

. If the SMBIOS data is not generated and filled correctly then the machine may behave unexpectedly. For example, a Mini PC that advertises ''Chassis Information , Type = Tablet'' may behave unexpectedly using Linux. A desktop manager like GNOME 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