# change BIOS settings using flashrom

## aZZe

Hi guys!

I would like to know if it is possible using flashrom to verify BIOS settings and possibly change them? For example turning VT support on/off or change boot order. I know you can use "flashrom -r <file>" to read the BIOS image but this means more doing a backup of your current BIOS. You can even update your BIOS using "flashrom -w <file>". But I just wanna simply change some settings or verify that they are set correctly.

Any ideas?

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## NeddySeagoon

aZZe,

Flashing your BIOS and changing the settings are not really related.

The mechanisms for both are quite sepataye too.

The CMOS (your settings) are only available at an I/O port. You have to set up the address in the CMOS you want to read/write than read/write the data value.

Only the first few bytes are standard and they are related to the Real Time Clock and a checksum.

The other bytes are 'user defined'. That is BIOS vendors use them as they like.  There is no stanaded and I'm not aware of anything being published.

Its possible but the hard bit is getting the data to do it.

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## roarinelk

BIOS settings are stored in the RTC's nvram

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## aZZe

That sounds very complicated. I mean I don't wanna brick my mainboard. I just wanted to compare a couple of PCs in the network and see if they have the same values like VT enabled or first boot device set to CD-ROM.

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## energyman76b

 *aZZe wrote:*   

> That sounds very complicated. I mean I don't wanna brick my mainboard. I just wanted to compare a couple of PCs in the network and see if they have the same values like VT enabled or first boot device set to CD-ROM.

 

did you have a look at dmidecode?

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## Logicien

Dmidecode only dump the devices data of the computer. It do not show full settings and even less modify them. Changing settings should not harm the machine. You need the good tool for it. Flashing the BIOS with flashroom can make at least a laptop become a brick.

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