How to update a mainboard system BIOS in Linux in a nutshell.

This is just a quick note to help Linux users flash a BIOS upgrade to their system. It’s not a step-by-step so easy your Grandma could do it. Sorry, there’s too many variables to create that. If you’ve ever downloaded and installed Linux via a USB drive this should be just as easy.

If your mainboard BIOS has a built-in utility to upgrade it’s BIOS, use that. It’s the best most foolproof way to go. Visit the website of your MoBo manufacturer for the BIOS update and flashing instructions. Generally all that’s needed is a USB thumb drive formatted to FAT.

If your mainboard does not have a built-in BIOS update feature, check with the manufacturer for options. Unfortunately, many mobo makers assume you have Windows and provide a utility that only runs in Windows or DOS. If you’re setup to dual-boot Linux or Windows, boot into Windows and use their utility. If you’re running Linux only:

1. Download the DOS based BIOS package from your mobo maker. Extract it into a folder of your choice, but keep the name simple as we’ll be using DOS in just a moment.

2. Visit and download the USB Installer version. Extract it and write the .img file to your USB drive. (hint: use the USB Image Writer utility or Unetbootin)

3. Verify freedos is on your USB drive. You should see autoexec.bat and other DOS looking files. (You may need to reboot your Linux box after initially creating the FreeDOS.)

4. Copy the folder where you extracted the BIOS package onto the FreeDOS USB drive.

5. Reboot the computer and select boot to FreeDOS USB drive.

6. Follow the menus, but don’t choose to install FreeDOS. Instead, exit to DOS.


At the C: prompt.


7. You should now be at a good old fashioned C: prompt. Change to the folder you made in step 4. Run the executable that starts the DOS based flashing utility. Follow the manufacturer’s instructions.

8. Reboot and confirm you have the new BIOS. You can also verify BIOS version in Linux by using the hardinfo utility or in a terminal type:

sudo dmidecode -s bios-version

That’s all there is to it. Easy as making a bootable floppy but better.


FreeDOS also runs in VirtualBox.


Side note: FreeDOS also works well in VirtualBox, although I would NOT advise trying to flash your BIOS while running in a virtual environment, best to do that as described above. Good to know if you have some old DOS games you want to run.



  • Kenn Ranous
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