DMIDECODE(8)                       System Manager's Manual                      DMIDECODE(8)

NAME
       dmidecode - DMI table decoder

SYNOPSIS
       dmidecode [OPTIONS]

DESCRIPTION
       dmidecode  is a tool for dumping a computer's DMI (some say SMBIOS) table contents in
       a human-readable format. This table contains a description of the  system's  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 doesn't 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 In-
       terface.  Both  standards are tightly related and developed by the DMTF (Desktop Man-
       agement Task Force).

       As you run it, dmidecode will try to locate the DMI table. It will first try to  read
       the  DMI  table from sysfs, and next try reading directly from memory if sysfs access
       failed.  If dmidecode succeeds in locating a valid DMI table, 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 board's 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.

       -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, system-uuid, system-family, baseboard-manufacturer, baseboard-product-
              name, baseboard-version, baseboard-serial-number,  baseboard-asset-tag,  chas-
              sis-manufacturer,  chassis-type, chassis-version, chassis-serial-number, chas-
              sis-asset-tag,  processor-family,  processor-manufacturer,  processor-version,
              processor-frequency.  Each keyword corresponds to a given DMI type and a given
              offset within this entry type.  Not all strings may be meaningful or even  de-
              fined  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 dmide-
              code exits with an error.  This option cannot be used more than once.

              Note: on Linux, most of these strings can alternatively be read directly  from
              sysfs,  typically from files under /sys/devices/virtual/dmi/id.  Most of these
              files are even readable by regular users.

       -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, chassis, 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 key-
              words is printed and dmidecode exits with an error.

       -H, --handle HANDLE
              Only display the entry whose handle matches HANDLE.  HANDLE is a 16-bit  inte-
              ger.

       -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.

           --dump-bin FILE
              Do not decode the entries, instead dump the DMI data to a file in binary form.
              The generated file is suitable to pass to --from-dump later.

           --from-dump FILE
              Read the DMI data from a binary file previously generated using --dump-bin.

           --no-sysfs
              Do  not  attempt  to read DMI data from sysfs files. This is mainly useful for
              debugging.

           --oem-string N
              Only display the value of the OEM string number N. The first  OEM  string  has
              number  1.  With  special  value "count", return the number of OEM strings in-
              stead.

       -h, --help
              Display usage information and exit

       -V, --version
              Display the version and exit

       Options --string, --type, --dump-bin and --oem-string determine the output format and
       are mutually exclusive.

       Please  note in case of dmidecode is run on a system with BIOS that boasts new SMBIOS
       specification, which is not supported by the tool yet, it  will  print  out  relevant
       message in addition to requested data on the very top of the output. Thus informs the
       output data is not reliable.

DMI TYPES
       The SMBIOS specification defines the following DMI types:

       Type   Information
       ────────────────────────────────────────────
          0   BIOS
          1   System
          2   Baseboard
          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
         40   Additional Information
         41   Onboard Devices Extended Information
         42   Management Controller Host Interface

       Additionally, type 126 is used for disabled entries and type 127 is  an  end-of-table
       marker. Types 128 to 255 are for OEM-specific data.  dmidecode will display these en-
       tries by default, but it can only decode them when the vendors have contributed docu-
       mentation or code for 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, 41
       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 bios

       • dmidecode --type BIOS

BINARY DUMP FILE FORMAT
       The binary dump files generated by --dump-bin and read using --from-dump are  format-
       ted as follows:

       • The  SMBIOS  or  DMI entry point is located at offset 0x00.  It is crafted to hard-
         code the table address at offset 0x20.

       • The DMI table is located at offset 0x20.

FILES
       /dev/mem       /sys/firmware/dmi/tables/smbios_entry_point        (Linux        only)
       /sys/firmware/dmi/tables/DMI (Linux only)

BUGS
       More  often  than  not, information contained in the DMI tables is inaccurate, incom-
       plete or simply wrong.

AUTHORS
       Alan Cox, Jean Delvare

SEE ALSO
       biosdecode(8), mem(4), ownership(8), vpddecode(8)

dmidecode                                March 2012                             DMIDECODE(8)

Usage: dmidecode [OPTIONS]
Options are:
 -d, --dev-mem FILE     Read memory from device FILE (default: /dev/mem)
 -h, --help             Display this help text and exit
 -q, --quiet            Less verbose output
 -s, --string KEYWORD   Only display the value of the given DMI string
 -t, --type TYPE        Only display the entries of given type
 -H, --handle HANDLE    Only display the entry of given handle
 -u, --dump             Do not decode the entries
     --dump-bin FILE    Dump the DMI data to a binary file
     --from-dump FILE   Read the DMI data from a binary file
     --no-sysfs         Do not attempt to read DMI data from sysfs files
     --oem-string N     Only display the value of the given OEM string
 -V, --version          Display the version and exit