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

       dmidecode - DMI table decoder

       dmidecode [OPTIONS]

       dmidecode  is a tool for dumping a computer's DMI (some say SMBIOS) ta-
       ble contents in a human-readable format. This table contains a descrip-
       tion  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  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.  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:

       o A handle. This is a unique identifier, which allows records to refer-
         ence  each  other.  For  example, processor records usually reference
         cache memory records using their handles.

       o 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".

       o 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.

       o 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.

       -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,
              baseboard-manufacturer,  baseboard-product-name,  baseboard-ver-
              sion, baseboard-serial-number, baseboard-asset-tag, chassis-man-
              ufacturer, chassis-type, chassis-version, chassis-serial-number,
              chassis-asset-tag,   processor-family,   processor-manufacturer,
              processor-version,  processor-frequency.   Each  keyword  corre-
              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.

              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 read-
              able 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, chas-
              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

       -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

              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 num-
              ber of OEM strings instead.

       -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

       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 entries by default, but it can only decode
       them when the vendors have contributed documentation 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:

       o dmidecode --type 0 --type 13

       o dmidecode --type 0,13

       o dmidecode --type bios

       o dmidecode --type BIOS

       The  binary  dump  files generated by --dump-bin and read using --from-
       dump are formatted as follows:

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

       o The DMI table is located at offset 0x20.

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

       More often than not, information contained in the DMI tables is inaccu-
       rate, incomplete or simply wrong.

       Alan Cox, Jean Delvare

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

dmidecode                         March 2012                      DMIDECODE(8)
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