


DMIDECODE(8)                                         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 com-
       ponents, 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  evolu-
       tions  (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 Manage-
       ment 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  Informa-
       tion
               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 reference 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".




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DMIDECODE(8)                                         DMIDECODE(8)


       o A  size. Each record has a 4-byte header (2 for the han-
         dle, 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.


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,  base-
              board-product-name,  baseboard-version,  baseboard-
              serial-number,  baseboard-asset-tag,  chassis-manu-
              facturer,  chassis-type,  chassis-version, chassis-
              serial-number, chassis-asset-tag, processor-family,
              processor-manufacturer,  processor-version, proces-
              sor-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  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  alterna-
              tively  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



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DMIDECODE(8)                                         DMIDECODE(8)


              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.

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

       -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 dis-
              played 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
              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 mes-
       sage in addition to requested data on the very top of  the
       output. Thus informs the output data is not reliable.





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DMIDECODE(8)                                         DMIDECODE(8)


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
       entries by default, but it can only decode them  when  the
       vendors have contributed documentation or code for them.



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DMIDECODE(8)                                         DMIDECODE(8)


       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


BINARY DUMP FILE FORMAT
       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.


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, incomplete or simply wrong.

AUTHORS
       Alan Cox, Jean Delvare

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






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