dmidecode

Dmidecode reports information about your system's hardware as described in your system BIOS according to the SMBIOS/DMI standard (see a sample output). This information typically includes system manufacturer, model name, serial number, BIOS version, asset tag as well as a lot of other details of varying level of interest and reliability depending on the manufacturer. This will often include usage status for the CPU sockets, expansion slots (e.g. AGP, PCI, ISA) and memory module slots, and the list of I/O ports (e.g. serial, parallel, USB).

Part of the dmidecode code can be found in the Linux kernel, where DMI data is used to enable or disable specific portions of code depending on the specific hardware. Thus, one use of dmidecode is for kernel developers to detect system "signatures" and add them to the kernel source code when needed.

Beware that DMI data have proven to be too unreliable to be blindly trusted. Dmidecode does not scan your hardware, it only reports what the BIOS told it to.

Dmidecode was first written by Alan Cox and is now being further developed and maintained by Jean Delvare. It is released under the General Public License (GPL). For more details, you should have a look at the AUTHORS and LICENSE files that come with the source code.

Three additional tools come with dmidecode:

• biosdecode prints all BIOS related information it can find (see a sample output);
• ownership retrieves the "ownership tag" that can be set on Compaq computers;
• vpddecode prints the "vital product data" information that can be found in almost all IBM computers (see a sample output).

Some documentation files are distributed with the source code:

• CHANGELOG, a list of the changes made to dmidecode
• README, which contains general information
• Manual pages.

Dmidecode is featured in the following articles:

• Differentiating between Similar Machines for Imaging
  Article by Luc Van de Velde, published on Novell Cool Solutions website.
• dmidecode: What's it good for?
  Article by Joe Barr, published on Newsforge.
• Scripting with dmidecode
  Article by Philip J. Hollenback, published on Newsforge.

Dmidecode is known to work on the following systems:

• Linux i386
• Linux x86_64
• Linux ia64
• FreeBSD i386
• FreeBSD x86_64
• NetBSD i386
• OpenBSD i386
• BeOS i386
• Cygwin i386

Source code is available for download. You can also get the latest sources using CVS.

No binaries are available here, but dmidecode is packaged for several Linux and BSD distributions (Debian, Gentoo and FreeBSD among others), either as a single package or included in a more generic tool set. A BeOS package is also known to exist.

• Project page (on Savannah)
• Mailing list archives
• Project page (on Freshmeat)
• SMBIOS specification
• CPUID specification
• Master MIF
• IPMI specification

Dmidecode is used by the following programs:

• Prtdiag, a bash script by Tom Callaway that generates a report describing the state of the hardware on the machine.
  Beware, it looks like prtdiag will only work with dmidecode 1.8 and former.
• Prtdiag (same name, but different script, how confusing), a ksh script by Jens Elkner that displays system configuration and diagnostic information on Linux systems.
• LM Sensors, a set of tools for monitoring the hardware health of Linux systems.
  From version 2.6.5 to version 2.8.1 of LM Sensors, the sensors-detect script relied on dmidecode to detect IBM systems, and its source code was even distributed with LM Sensors. From version 2.8.2 to version 2.8.8, the method implemented in vpddecode was reimplemented in Perl instead.

The dmidecode code was copied and integrated into the following programs:

• Powertweak Linux, a hardware information gathering and Linux system tweaking tool.
• Lshw, a Linux hardware listing tool.

Alternative implementations of a DMI table decoder:

• libsmbios