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 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.

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.

	   --no-quirks
	      Decode everything exactly as it is in the table, without trying
	      to fix up common mistakes or hide irrelevant fields.  This mode
	      is primarily aimed at firmware developers.

       -s, --string KEYWORD
	      Only display the value of the DMI string identified by KEYWORD.
	      It 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.

	   --list-strings
	      List available string keywords, which can then be passed to the
	      --string option.

       -t, --type TYPE
	      Only display the entries of type TYPE. It 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.

	   --list-types
	      List available type keywords, which can then be passed to the
	      --type option.

       -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.  FILE must not exist.

	   --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 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 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

BINARY DUMP FILE FORMAT
       The binary dump files generated by --dump-bin and read using --from-
       dump are formatted 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.

UUID FORMAT
       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.

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)

dmidecode			 February 2023			  DMIDECODE(8)