Dmidecode
from the man command:
Reformatting dmidecode(8), please wait... DMIDECODE(8) DMIDECODE(8)
NAME
dmidecode - DMI table decoder
SYNOPSIS
dmidecode [OPTIONS]
DESCRIPTION
dmidecode is a tool for dumping a computerâs DMI (some say SMBIOS) table contents in a human-readable format. This table contains a description of the systemâs hardware components, as well as other useful pieces of information such as serial numbers and BIOS revision. Thanks to this table, you can retrieve this information without having to probe for the actual hardware. While this is a good point in terms of report speed and safeness, this also makes the presented information possibly unreliable.
The DMI table doesnât only describe what the system is currently made of, it also can report the possible evolutions (such as the fastest supported CPU or the maximal amount of memory supported).
SMBIOS stands for System Management BIOS, while DMI stands for Desktop Management Interface. Both standards are tightly related and developed by the DMTF (Desktop Management Task Force).
As you run it, dmidecode will try to locate the DMI table. If it succeeds, it will then parse this table and display a list of records like this one:
Handle 0x0002
DMI type 2, 8 bytes.
Base Board Information
Manufacturer: Intel
Product Name: C440GX+
Version: 727281-001
Serial Number: INCY92700942
Each record has:
- A handle. This is a unique identifier, which allows records to reference each other. For example, processor records usually reference cache memory 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 boardâs manufacturer, model, version and serial number.
OPTIONS
-d, --dev-mem FILE
Read memory from device FILE (default: /dev/mem)
-q, --quiet
Be less verbose. Unknown, inactive and OEM-specific entries are
not displayed. Meta-data and handle references are hidden. Mutuâ
ally exclusive with --dump.
-s, --string KEYWORD
Only display the value of the DMI string identified by KEYWORD.
KEYWORD must be a keyword from the following list: bios-vendor,
bios-version, bios-release-date, system-manufacturer, system-
product-name, system-version, system-serial-number, baseboard-
manufacturer, baseboard-product-name, baseboard-version, baseâ
board-serial-number, baseboard-asset-tag, chassis-manufacturer,
chassis-version, chassis-serial-number, chassis-asset-tag, proâ
cessor-manufacturer, processor-version. Each keyword correâ
sponds to a given DMI type and a given offset within this entry
type. Not all strings may be meaningful or even defined on all
systems. Some keywords may return more than one result on some
systems (e.g. processor-version on a multi-processor system).
If KEYWORD is not provided or not valid, a list of all valid
keywords is printed and dmidecode exits with an error. This
option cannot be used more than once, and implies --quiet.
Mutually exclusive with --type and --dump.
-t, --type TYPE
Only display the entries of type TYPE. TYPE can be either a DMI
type number, or a comma-separated list of type numbers, or a
keyword from the following list: bios, system, baseboard, chasâ
sis, processor, memory, cache, connector, slot. Refer to the DMI
TYPES section below for details. If this option is used more
than once, the set of displayed entries will be the union of all
the given types. If TYPE is not provided or not valid, a list
of all valid keywords is printed and dmidecode exits with an
error. Mutually exclusive with --string.
-u, --dump
Do not decode the entries, dump their contents as hexadecimal
instead. Note that this is still a text output, no binary data
will be thrown upon you. The strings attached to each entry are
displayed as both hexadecimal and ASCII. This option is mainly
useful for debugging. Mutually exclusive with --quiet and
--string.
-h, --help
Display usage information and exit
-V, --version
Display the version and exit
DMI TYPES
The SMBIOS specification defines the following DMI types:
Type Information
----------------------------------------
0 BIOS
1 System
2 Base Board
3 Chassis
4 Processor
5 Memory Controller
6 Memory Module
7 Cache
8 Port Connector
9 System Slots
10 On Board Devices
11 OEM Strings
12 System Configuration Options
13 BIOS Language
14 Group Associations
15 System Event Log
16 Physical Memory Array
17 Memory Device
18 32-bit Memory Error
19 Memory Array Mapped Address
20 Memory Device Mapped Address
21 Built-in Pointing Device
22 Portable Battery
23 System Reset
24 Hardware Security
25 System Power Controls
26 Voltage Probe
27 Cooling Device
28 Temperature Probe
29 Electrical Current Probe
30 Out-of-band Remote Access
31 Boot Integrity Services
32 System Boot
33 64-bit Memory Error
34 Management Device
35 Management Device Component
36 Management Device Threshold Data
37 Memory Channel
38 IPMI Device
39 Power Supply
Additionally, type 126 is used for disabled entries, type 127 is an
end-of-table marker, and types 128 to 255 are for OEM-specific data.
dmidecode will display these entries by default, but cannot decode
them.
Keywords can be used instead of type numbers with --type. Each keyword
is equivalent to a list of type numbers:
Keyword Types
------------------------------
bios 0, 13
system 1, 12, 15, 23, 32
baseboard 2, 10
chassis 3
processor 4
memory 5, 6, 16, 17
cache 7
connector 8
slot 9
Keywords are matched case-insensitively. The following command lines
are equivalent:
- dmidecode --type 0 --type 13
- dmidecode --type 0,13
- dmidecode --type 0 --type 13
- dmidecode --type 0,13
- dmidecode --type bios
- dmidecode --type BIOS
FILES
/dev/mem
BUGS
More often than not, information contained in the DMI tables is inaccuâ
rate, incomplete or simply wrong.
AUTHORS
Alan Cox, Jean Delvare
SEE ALSO
biosdecode(8), mem(4), ownership(8), vpddecode(8)
dmidecode August 2005 DMIDECODE(8)
Example output
Here's a snippet of output on an ESX host when displaying memory info:
Handle 0x0028
DMI type 17, 27 bytes.
Memory Device
Array Handle: 0x0025
Error Information Handle: No Error
Total Width: 76 bits
Data Width: 72 bits
Size: 1024 MB
Form Factor: DIMM
Set: 1
Locator: DIMM 2A
Bank Locator: Bank0 Bank1
Type: DDR
Type Detail: Synchronous
Speed: 266 MHz (3.8 ns)
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
