Asus M4A87T add AM3+ CPU support via M5A87

[siryoink]

Curious on the possibility of adding AM3+ CPU support to the Asus M4A87T line of boards.  The M5A87 board is nearly identical, using the same AMD 870/SB850 chipset.  The physical layout of all surface mount components is identical, save for one change, the addition of an ASM1042 chip replacing the old USB chip to support USB3.0, and one capacitor and resistor relocated near this chip. 

Pics of each board for comparison can be viewed here:
https://www.asus.com/Motherboards/M4A87T/gallery/
https://www.asus.com/Motherboards/M5A87/gallery/


M4A87T BIOS:
http://dlcdnet.asus.com/pub/ASUS/mb/sock...S-0501.zip

M5A87 BIOS:
http://dlcdnet.asus.com/pub/ASUS/mb/Sock...S-1506.zip

I poked around in these and couldn't seem to find the AGESA code in the M5A87.  Anyone else have a minute to take a glance?

Update:

The OLD version of the M5A87 bios, prior to having update for the FX series AM3+ CPU's added, did have the same code in 1B the M4A87T had.

Linky:
http://dlcdnet.asus.com/pub/ASUS/mb/Sock...S-0331.zip

[DeathBringer]

Injecting new version of AGESA isn't enough to boot FX series CPUs.

[siryoink]

Actually, the m5a87 did not support the FX series at release either. It was originally a product refresh of the m4a87 with an external usb3 chip added, as the sb on the older board did not support usb3 natively. The major difference is the board is newer and asus elected to support it with bios updates.

Same nb/sb, same vrm's.

What do you believe this board is lacking to boot the FX series?

[DeathBringer]

Have you second flash chip for backup? You can try flash BIOS from M5A87. But I think it will be unsuccessful trial.

[siryoink]

Have you second flash chip for backup? You can try flash BIOS from M5A87. But I think it will be unsuccessful trial.

I don't believe it will work completely unmodified, but might try it anyways.  Suspect it might fail if it looks for the ASM1042 at any point on boot-up, which is why I was hoping to be able to extract cpu microcode and agesa from that one.  I have three boards here that use the same type of bios chip, and have hotflashed them before when I was working on one of them and broke it.

[DeathBringer]

You can disable USB in BIOS before flashing.

[siryoink]

Getting an error that this bios isn't compatible with AFUDOS.  Weird, because that's what I've used for every other AMI flash I've done. 

Asus site has a file named BUPDATER.EXE , which of course won't let me flash a non-original file due to the size being different.

Any ideas what else to use?

[DeathBringer]

So you need compatible flash chip with size 2 Mb.

[siryoink]

So you need compatible flash chip with size 2 Mb.

Would be easy to swap out, but don't have one on-hand. 

Since most people who have this board wouldn't have that, even if I did get one and make it work, brings me back around to the original question.  I know some people around here have had luck replacing AGESA on these ASUS boards.  I did it myself on an old Compaq board, but can't seem to find what I'm looking for in this one.