Creating custom bios update file

[whoislinus]

I inherited an Asus G10AC which I've overhauled, literally only the motherboard and i7 4770s (yes, s, sigh...) remain. I've no options for memory settings in the current BIOS and setting any XMP profile won't save (or fails, who knows).

 

Whilst checking that I had the latest BIOS update I noticed the .CAP file was called 'H87M-PRO-ASUS-G10AC-1101.CAP'. As you can see, the board is actually a H87M-PRO (branded and reporting as G10AC) which features the same BIOS updates until 1101 but, unlike the G10AC page, goes on to BIOS updates from last year supporting all sorts of lovely things which may solve my XMP/memory issues.

 

Having tried to flash the BIOS (I've nothing to lose really) using the latest H87M-PRO BIOS .CAP I get 'The model of the bios image doesn't match the BIOS ROM currently present' in Windows or 'security check failed' via the updater in BIOS. Any ideas whether/how I can modify the .CAP file to get this working?

 

I've attached an image of the board for shits and giggles - it looks a bit lost in a Corsair 540!

[fire219]

First of all, I hope you know what you want to do is extremely dangerous and very likely to kill your motherboard if anything goes slightly wrong.

 

With that being said, BIOS updates generally have identification info in the header (first few bytes of the file), which are checked by the motherboard before install. If someone could find the format of that header, and copy that of the G10AC into the new update, chances are it would work.

 

I might mess with this idea some, I'm curious now.

[fire219]

I just cut the CAP header from the latest official G10AC BIOS update and put it on H87M-PRO-2102. This is not likely to work, but it's the best I can do without reverse engineering how the BIOS is structured. 

 

Use at your own risk.

H87M-PRO-ASUS-G10AC-2102.zip

[whoislinus]

Many thanks for taking a look, unfortunately the Windows based BIOS update tool still doesn't like the .CAP, stating:

 

'The mode of the BIOS image doesn't match the BIOS ROM currently present'

 

Still eager to give this a shot, happy to be the guinea pig as others begin to take the shoddy (but not inexpensive) G10AC and attempt to make it the machine it should have been.

[fire219]

51 minutes ago, whoislinus said:

Many thanks for taking a look, unfortunately the Windows based BIOS update tool still doesn't like the .CAP, stating:

 

'The mode of the BIOS image doesn't match the BIOS ROM currently present'

 

Still eager to give this a shot, happy to be the guinea pig as others begin to take the shoddy (but not inexpensive) G10AC and attempt to make it the machine it should have been.

Attempt 2. Looked much more carefully at the file this time and replaced references to model numbers and names where they looked relevant.

H87M-PRO-ASUS-G10AC-2102.zip

[whoislinus]

Will give it a go tomorrow and report back.

 

QQ - how did you view the contents?

[fire219]

Just now, whoislinus said:

Will give it a go tomorrow and report back.

 

QQ - how did you view the contents?

I'm just using Notepad++. It doesn't do anything fancy with showing code properly, but it's enough to get hints as to the structure of the system as well as readable strings.

 

If this attempt doesn't work, the code itself might need to be dissected, which is a bit above my skill level.

[whoislinus]

Had a try and still getting the same error. Thank you for your assistance anyway.

[fire219]

Just now, whoislinus said:

Had a try and still getting the same error. Thank you for your assistance anyway.

Alright. Sorry I couldn't get it working.

[Alexis91150]

Hi, I have the same problem.
I have a G10AC/ H87M-PRO motharboard. My actually bios is v1101 for Asus g10ac.

 

I want to do it because I bought a ssd nvme samsung evo970plus and I want to start on this one.
Have you some news ideas to do a custom bios for upgrade the bios of G10AC motherboard to H87MPRO motherboard ?