The Desktop Management Interface (DMI) generates a standard framework for managing and tracking components in a desktop, notebook or server components , by abstracting these components from the software that manages them. Modern mother boards are compatible with this standard. For a lay user it means that the BIOS settings can be watched from your OS. DMI standards are published by Distributed Management Task Force (DMTF) into desktop-management standards. They also provide a related standard named SMBIOS (System Management BIOS ).
On linux systems , you can watch various system parameters using dmidecode command. You have to be superuser to display dmi information.
As you run it, dmidecode will try to locate the DMI table. It will print a long list of information. A sample entry is shown below.
Handle 0x0002, DMI type 2, 16 bytes Base Board Information Manufacturer: Quanta Product Name: QL8 Version: UnIn Serial Number: QTF2QQ84200536 Asset Tag: Base Board Asset Tag Features: Board is a hosting board Board is replaceable Location In Chassis: Base Board Chassis Location Chassis Handle: 0x0003 Type: Motherboard Contained Object Handles: 0
If you look closely , each record has
· A handle. This is a unique identifier, which allows records to reference each other. For example, processor records usually reference cache mem‐
ory records using their handles.
· A type. The SMBIOS specification defines different types of elements a computer can be made of. In this example, the type is 2, which means that
the record contains “Base Board Information”.
· A size. Each record has a 4-byte header (2 for the handle, 1 for the type, 1 for the size), the rest is used by the record data. This value
doesn’t take text strings into account (these are placed at the end of the record), so the actual length of the record may be (and is often)
greater than the displayed value.
· Decoded values. The information presented of course depends on the type of record. Here, we learn about the board’s manufacturer, model, version
and serial number.
There is also a related command named biosdecode which prints a shorter description.
# biosdecodebiosdecode 2.9 ACPI 2.0 present. OEM Identifier: Quanta RSD Table 32-bit Address: 0x7BBFE0AC XSD Table 64-bit Address: 0x000000007BBFE120 PNP BIOS 1.0 present. Event Notification: Not Supported Real Mode 16-bit Code Address: F000:B9EE Real Mode 16-bit Data Address: 0040:0000 16-bit Protected Mode Code Address: 0x000FB9F9 16-bit Protected Mode Data Address: 0x00000400 OEM Device Identifier: SST2400 SMBIOS 2.4 present. Structure Table Length: 1553 bytes Structure Table Address: 0x000E51A0 Number Of Structures: 33 Maximum Structure Size: 226 bytes PCI Interrupt Routing 1.0 present. Router ID: 00:1f.0 Exclusive IRQs: None Compatible Router: 8086:122e