Hi,
So basically, TSX (an Intel extension) is gimped in the latest microcode ‘AE’ on my 9700k due to security implementations (TSX is used in the PS3 emulator RPCS3). Stupidly, before I knew this I had updated to the latest BIOS.
Version 4.00 (& 4.10+4.20) here mentions that ‘User will not able to flash to previous BIOS once upgrading to this BIOS version.’ 4.00 has the A2 microcode (the one I wish to downgrade to). I know that at the very least I was able to downgrade from 4.10 to 4.01 (both AE microcode). However, I have a hunch that it won’t restore the A2 microcode if I try to flash 4.00, instead keeping me with the same Management Engine version + AE microcode.
If this is the case, would Lost_N_BIOS’s guide work here=
I just wanted to ensure that no revelations have come out in regards to Asrock Z390 boards and there is minimal risk if I just grab the 4.00 BIOS and flash it using the fptw -bios -f bios.rom command
Thank you all kindly!
EDIT:
Reading further it looks like I need to amalgamate my serials from my current bios (having first backed up with the tool) with the stock 4.00 bios, not quite sure how to do that though. Soothing words would be appreciated, a nice lullaby
@Shrib - ME FW has nothing to do with what you mentioned, you only need the microcode changed out. So yes, dump BIOS region with FPT, get your BIOS Lock and or SMI lock variables if both enabled, disable those via grub, then boot back to windows and make a new FPT dump.
This last FPT dump will be your new base BIOS to edit, this way those locks are disabled already for you next time you want to FPT flash (Unless/until you again flash in stock BIOS)
Then, edit that FPT dump, put in the microcode you want, fix FIT table if required and then reflash via FPT
Serials, UUID etc, all will be varied over from your FPT Dump, you don’t need to do anything in regards to this, as long as you do not FPT flash stock BIOS (this is why you shouldn’t use stock BIOS with FPT)
If you want me to do the edits for you, do your first FPT dump and unlock the locks in grub, then dump BIOS region with FPT again and send me that and I will put in the A2 microcode for you (Unless you got it from here 
)
YOu probably will have to do this too, if using Win8-10
Intel, AMD, VIA & Freescale CPU Microcode Repositories Discussion (19)
@Lost_N_BIOS
Last time I made a brief post about this you said that “Try method on page 2 @Shrib. this does not matter about Asrock’s new security method - heed the red warning to use backup to modify/reflash, so you don’t loose system specific details”. Does this mean I don’t need to fiddle with SMI lock/BIOS lock variables (assuming I’d just need to follow the guide if I do)?
What I’ll be able to do is flash 4.00 using Asrock’s Q-Flash (probably won’t change MC), I can then dump that BIOS and use UEFI BIOS Updater to switch the Microcode out and flash using the command?
You are a hero!