Provided by: dmidecode_3.3-3ubuntu0.1_amd64 bug


       dmidecode - DMI table decoder


       dmidecode [OPTIONS]


       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
       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:

       • 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.


       -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,
              bios-revision, firmware-revision, system-manufacturer, system-product-name, system-
              version,  system-serial-number,  system-uuid,   system-sku-number,   system-family,
              baseboard-manufacturer,   baseboard-product-name,   baseboard-version,   baseboard-
              serial-number, baseboard-asset-tag,  chassis-manufacturer,  chassis-type,  chassis-
              version,  chassis-serial-number,  chassis-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 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 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 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 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.

              Do  not  attempt  to  read  DMI  data  from  sysfs files. This is mainly useful for

           --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 message
       in addition to requested data on the very top of the output. Thus informs the output  data
       is not reliable.


       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:

       • dmidecode --type 0 --type 13

       • dmidecode --type 0,13

       • dmidecode --type bios

       • dmidecode --type BIOS


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

       • 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.


       There  is  some  ambiguity  about  how  to  interpret  the  UUID  fields  prior  to SMBIOS
       specification version 2.6. There was no mention of byte swapping, and RFC 4122  says  that
       no  byte  swapping should be applied by default. However, SMBIOS specification version 2.6
       (and later) explicitly states that the first 3 fields  of  the  UUID  should  be  read  as
       little-endian  numbers  (byte-swapped).  Furthermore, it implies that the same was already
       true for older versions of the  specification,  even  though  it  was  not  mentioned.  In
       practice,  many hardware vendors were not byte-swapping the UUID. So, in order to preserve
       compatibility, it was decided to interpret the UUID fields according to RFC 4122 (no  byte
       swapping)  when  the SMBIOS version is older than 2.6, and to interpret the first 3 fields
       as little-endian (byte-swapped) when the SMBIOS version is 2.6 or later. The Linux  kernel
       follows the same logic.


       /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 inaccurate, incomplete or
       simply wrong.


       Alan Cox, Jean Delvare


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