Downgrade Your BIOS Using 'flashrom'
Wednesday, February 24, 2010 5:23:55 PM
Yesterday I was stuck in a very awkward situation involving my BIOS. Basically I had to upgrade it to support new hardware, but the upgrade lost support for some of the old hardware, namely my RAID0 array! Let me explain:
About a week ago I purchased a new graphics card. This particular graphics card (ATI Radeon HD3850X2) was newer than my motherboard (ASUS M2N-SLI Deluxe), therefore when I switched my computer on with the new graphics card installed there was no display as the BIOS did not support it.
So I did the logical thing and upgraded to the latest BIOS. There are a number of ways to do this on an ASUS board, the easiest being to put the new BIOS image file on a USB stick, boot up and enter setup and go into the 'EZFlash' program. EZFlash finds image files on the USB stick, uploads a new one and downloads a copy of the old one for backup.
When I rebooted, however, I discovered that ASUS had cleverly not thought about making an existing RAID array backward compatible with the new BIOS software. In fact, the RAID BIOS isn't even available, meaning I was unable to boot at all.
No big deal, I thought. I had backed up the old BIOS so at least I could get things back to normal by downgrading again. Wrong. When I went back into EZFlash to upload the old BIOS again, all it managed to come up with was 'Cannot downgrade - BIOS unsuitable for system'. Thanks, ASUS!
I tried the different methods ASUS provides to try and get the old BIOS back on. I tried Unetbootin to make a FreeDOS USB bootdisk and used awdflash.exe whilst in FreeDOS to flash the BIOS. Nope, same complaint. I couldn't try the Windows utility as I was unable to boot.
After scratching my head for a long while, I came across a program called 'flashrom'. Flashrom is a free and open source tool which, among other things, is able to flash your BIOS without the restriction I thus far had encountered.
Installing flashrom
I booted into an Ubuntu 9.10 Live CD. To install I made sure that 'universe' and 'multiverse' were enabled, like I did on step 2 of installing Adobe Flash for Opera, then I typed the following in the command line:
$ sudo apt-get update
$ sudo apt-get install flashrom
Once flashrom is installed, you will want to check that your motherboard is supported by looking at the list of supported hardware. If there is a similar motherboard with the same chipset as yours, yours will probably be OK too. For instance mine is not listed, but the MCP55 chipset is, so I was quite confident it would work.
Using flashrom
Using flashrom is easy. Remember you must have root privileges. It's command line but it is very simple:
1. First, in a terminal, navigate to the folder where the BIOS file you intend to upload is stored.
2. Get a copy of your current BIOS for backup purposes:
$ sudo flashrom --read oldbios.bin
3. Flash the BIOS, replacing it with the new one:
$ sudo flashrom --write newbios.bin
If it goes wrong, DO NOT RESTART OR TURN OFF THE COMPUTER. The flashrom team recommends that you head over to their IRC channel and let them help you sort it out if this happens. Bear in mind if it does go wrong and you do turn the computer off, you won't be able to restart again. The flashrom channel is #flashrom on irc.freenode.net.
If you can verify that your motherboard works and it is not on the list, remember to help out the project by sending your results to the mailing list.
Thanks go to the flashrom contributors for enabling me to use my computer again, and to you for reading this far!







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