Get Information About Your BIOS / Server Hardware From a Shell Without Opening Chassis ( BIOS Decoder )

by Vivek Gite · 21 comments

biosdecode is a command line utility to parses the BIOS memory and prints information about all structures (or entry points) it knows of. You can find out more information about your hardware such as:
=> IPMI Device
=> Type of memory and speed
=> Chassis Information
=> Temperature Probe
=> Cooling Device
=> Electrical Current Probe
=> Processor and Memory Information
=> Serial numbers
=> BIOS version
=> PCI / PCIe Slots and Speed
=> Much more

biosdecode parses the BIOS memory and prints the following information about all structures :
=> SMBIOS (System Management BIOS)
=> DMI (Desktop Management Interface, a legacy version of SMBIOS)
=> SYSID
=> PNP (Plug and Play)
=> ACPI (Advanced Configuration and Power Interface)
=> BIOS32 (BIOS32 Service Directory)
=> PIR (PCI IRQ Routing)
=> 32OS (BIOS32 Extension, Compaq-specific)
=> VPD (Vital Product Data, IBM-specific)
=> FJKEYINF (Application Panel, Fujitsu-specific)

In this tip you will learn about decoding BIOS data (dumping a computer's DMI ) and getting all information about computer hardware without rebooting the server.

More about the DMI tables

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.

dmidecode - Read biosdecode data in a human-readable format

Data provided by biosdecode is not in a human-readable format. You need to use dmidecode command for dumping a computer’s DMI (SMBIOS) table contents on screen. 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.

Task: Display information about IPMI Device

# dmidecode --type 38
Output:

# dmidecode 2.7
SMBIOS 2.4 present.

Handle 0x0029, DMI type 38, 18 bytes.
IPMI Device Information
        Interface Type: KCS (Keyboard Control Style)
        Specification Version: 2.0
        I2C Slave Address: 0x10
        NV Storage Device: Not Present
        Base Address: 0x0000000000000CA2 (I/O)
        Register Spacing: Successive Byte Boundaries

Task: Display information about PCI / PCIe Slots

# dmidecode --type 9

# dmidecode 2.7
SMBIOS 2.4 present.

Handle 0x000E, DMI type 9, 13 bytes.
System Slot Information
        Designation: PCIX#1-133MHz
        Type: 64-bit PCI-X
        Current Usage: Available
        Length: Long
        ID: 1
        Characteristics:
                3.3 V is provided

Handle 0x000F, DMI type 9, 13 bytes.
System Slot Information
        Designation: PCIX#2-100MHz
        Type: 64-bit PCI-X
        Current Usage: Available
        Length: Long
        ID: 2
        Characteristics:
                3.3 V is provided

Handle 0x0010, DMI type 9, 13 bytes.
System Slot Information
        Designation: PCIE#3-x8
        Type: Other
        Current Usage: Available
        Length: Other
        Characteristics:
                3.3 V is provided

Handle 0x0011, DMI type 9, 13 bytes.
System Slot Information
        Designation: PCIE#4-x8
        Type: Other
        Current Usage: Available
        Length: Other
        Characteristics:
                3.3 V is provided

Handle 0x0012, DMI type 9, 13 bytes.
System Slot Information
        Designation: PCIE#5-x8
        Type: Other
        Current Usage: Available
        Length: Other
        Characteristics:
                3.3 V is provided

Task: Find out Information about BIOS

# dmidecode --type 0
Output:

# dmidecode 2.7
SMBIOS 2.4 present.
Handle 0x0000, DMI type 0, 24 bytes.
BIOS Information
        Vendor: Phoenix Technologies LTD
        Version: 6.00
        Release Date: 01/26/2007
        Address: 0xE56C0
        Runtime Size: 108864 bytes
        ROM Size: 1024 kB
        Characteristics:
                PCI is supported
                PNP is supported
                BIOS is upgradeable
                BIOS shadowing is allowed
                ESCD support is available
                Boot from CD is supported
                Selectable boot is supported
                EDD is supported
                3.5"/2.88 MB floppy services are supported (int 13h)
                ACPI is supported
                USB legacy is supported
                LS-120 boot is supported
                ATAPI Zip drive boot is supported
                BIOS boot specification is supported
                Targeted content distribution is supported

Understanding BIOS keywords

dmidecode --type {KEYWORD / Number }

You need to pass dmidecode following keywords:

  • bios
  • system
  • baseboard
  • chassis
  • processor
  • memory
  • cache
  • connector
  • slot

All DMI types you need to use with dmidecode --type {Number}:

# Type Short Description
0 BIOS
1 System
2 Base Board
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

Display Power supply information, enter:
# dmidecode --type 39
Display CPU information, enter:
# dmidecode --type processor
Read man page for more information:
$ man dmidecode

Other tools and commands to gather hardware information

Updated for accuracy.

Featured Articles:

Want to read Linux tips and tricks, but don't have time to check our blog everyday? Subscribe to our daily email newsletter to make sure you don't miss a single tip/tricks. Subscribe to our weekly newsletter here!

{ 21 comments… read them below or add one }

1 Daemones 01.25.08 at 2:14 am

Very Very Good
thank :D

2 tiger74 01.25.08 at 7:06 am

Very nice article! It helps me in writing documentation about servers.
Thanks vivek :)

3 rahul 01.25.08 at 12:05 pm

gud one !! i think i will learn lots new things from this site !! thx buddy :)

4 ezeze5000 01.25.08 at 12:19 pm

Works in Ubuntu Desktop 7.10, if you put the SUDO command in front of it.

5 Patrick Anderson 01.26.08 at 5:53 pm

The last few examples have the typo: “midecode” instead of “dmidecode”.

6 vivek 01.26.08 at 7:16 pm

Patrick,

Thanks for the heads up!

7 xingtian.zhang 01.29.08 at 12:31 am

That’s very good.

8 Dan 01.29.08 at 11:53 am

Thanks for this, very handy :D

9 Raj 01.29.08 at 1:48 pm

+1 thanks – very handy tool

10 kkd 03.10.08 at 9:01 am

hi, I will study to vsftpd. I want help me to source.

11 Ryan D 03.21.08 at 7:53 pm

i work in a school as a IT manager. i need to get into the bios through command prompt and check the memory and other things. what is the code to do so.

all suggestions would be kindly accepted

12 vivek sharma 08.08.08 at 6:48 am

i am frequent visitor to this site and i get lot of suitable information. please help me in writing shell script for getting information of thumb drive like id no., name of manufacturer, hostname who has inserted in etc… similarly for CDROM also…
please help me out…
thanks
regards

13 Harpreet 09.05.08 at 6:21 am

Thanks Buddy :) Its works

14 Gaurav 12.16.08 at 1:16 pm

It’s great and I got more than what I want.

:)

15 Giovanni 03.13.09 at 2:37 pm

Great resource!
Thanks!

16 Francisco Ramirez 04.28.09 at 8:41 pm

Very good tool, however it would be nice if you could do a compressed list like lshw -short does.
Just my 2cents tho.

17 Hilaire 05.14.09 at 4:19 pm

Do you have a Bios Decoder for Windows servers in a script format or command to obtain the same information described in this article.
Very intersting article indeed.
Thank you, Zirigo

18 Anand Babu 10.01.09 at 11:55 am

i really love it

thanks,

19 Nix 10.08.09 at 10:23 am

Nice…. :-)

Is there any way from where I can change BIOS values/options from Linux Console.
e.g. Changing Boot priority from HDD to CDROM or PXE.

20 SIFE 11.24.09 at 2:57 pm

Salamo Alikom
can i do this in assembly ?

21 Charanjit Singh 01.02.10 at 12:42 pm

Nice Article, really helpful in audit.

Leave a Comment

You can use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Previous post:

Next post: