[Guide] How to flash a modded AMI UEFI BIOS

[peggidead]

My old p8b75-v asus motherboard (.CAP Bios) don’t have USB Flashback features and i’m not buying pcie to nvme adapter before ensure bios is modable so i can’t use AMI AFU method.
AI Suite is not available for Windows 10 so i had to install Windows 8.1 and use it to flash and voila it worked

Use UEFITool load BiosOgirinal.CAP, search text “CSMCORE”, scroll down to the last entry before “Volume free space” and insert after NvmExpressDxe final save to file Modded.CAP
Open Ai Suite → Asus Update → Update BIOS from file → Choose BiosOgirinal.CAP → after it loaded don’t click next → Delete BiosOgirinal.CAP and rename Modded.Cap to BiosOgirinal.CAP → now you can click next and flash it

[Fernando]

@peggidead
Welcome to the Win-Raid Forum and congratulations for having succeeded!
Enjoy the speed of an NVMe SSD being used as system drive!

[Gregory_Tumanyan]

@Fernando As an MSI Z370 owner I want to write a short guide about flashing a modded BIOS:

Just use FPTW64 -bios -f mod_bios.bin from the corresponding CSME System Tools.
No other tools are needed.

[Fernando]

@Gregory_Tumanyan
Thank you very much for your short guide about how to get a modded MSI BIOS properly flashed by using the Intel FPT tool.
To make it easier for the MSI mainboard users, your guide has been quoted by me within the first post of this thread.

[euranooo]

I managed to successfully flash modified bios to ASRock x570 phantom gaming 4 using flashrom. Original board bios version was 2.20 ( notice that it’s before AGESA 1.2 update came ) and I flashed newest version with mod applied.

[Huike]

My personal experience of this guide. Thanks for this guide first. It helped me to flash an Asus H87i-Plus board and an Asus P8Z77-V-Pro board with modded UEFI BIOS to support boot from NVMe M.2 SSD on a PCIe to M.2 NVMe adapter. My experience has slightly different part from the guide. See below:

1. Use UEFITool 0.28.0 to extract the BIOS body as .rom file.
2. I found out that the H87i-Plus .cap file missing the PcieLaneDxe.ffs driver. So I downloaded a Asus Z87 .cap bios and extracted it from the bios file. Use the “Extract as is…” command.
3. Use the same UEFITOOL 0.28.0 to open the H87iP.rom extracted before. Find the CSMCORE part and scroll down to the last line of the DXE driver region, insert the previously extracted PcieLaneDxe.ffs and the downloaded NvmExpressDxe_5.ffs, then save the image. Then open it again and compare it with the original .rom file to make sure there is no errors.
4. Flash the modded BIOS. This part is a bit hard. I have read many guides and tried many different methods and finally flashed it. Couple of things first: The Asus flashback method is easy, I used it to flash my modded Z77VP.cap easily. But for the H87i-Plus there is no flashback method. I tried AMI AFU for DOS core8, Aptio 4 and Aptio 5 in Freedos 1.3. All not working. The Aptio 5 and Core8 just crashed. The Aptio 4 just saying the BIOS is write protected so it even can’t read the BIOS. Tried different AFUWinx64 versions on Windows 11 and they never worked. So I have to install Windows 10 on the H87i-Plus machine and finally use the AFUWINx64 3.05.04 with GAN option to flash it. It worked. The only thing different from this guide is that you don’t need to flash the original .cap BIOS first. Just flash the modded .rom file as below:

AFUWINX64.EXE MODDED_ROM.ROM /GAN

And It was successful. After reboot I can boot Windows 10 from the NVMe disk.

But there is one issue with my H87i-Plus board. I use this board to build a NAS using TrueNas-Scale 24.10.0.2. The TrueNas Scale can be installed onto the NVMe disk, But it can’t boot. No options in the BIOS. Windows 10 and 11 can boot correctly from the NVMe disk. So some further digging needed.

Hope these experience will help somebody.

Thanks again for this guide.

[kenshin_1997]

hello brother greetings
I hope you have a happy holiday brother look I have a big problem I have the asrock x99 extreme 4 with the bios 3.80 of the year 2018 is its original bios with an xeon e5 2698v3 but I tell you probe all the methods that you comment on the thread above and none work by editing bios with the UBU
much less edit the bios by DOS
I get a message that the bios is protected x region and that you can not copy it much less edit it nothing allows me and with the UBU
it comes out that the protection has not been removed already the truth that I do not know what to do since this xeon has a turbo boss not despicable of 3.6 ghz in all its nuclei but for now I only reach with luck the 2.8ghz nothing more and I am losing enough with the xeon so you have some idea how to get the mod of the active turbo on this board for the series e5 26xv3 if you can share it a lot bro te I have a lot of time.
happy 2025

[Fernando]

@kenshin_1997
Have you already tried to use an old UBU tool v1.79.xx?

[Nameless]

| ASRock B450 Pro4 MOBO |

Hello World,

I’m seeking guidance.
I’ve attempted to follow several passages on this site now.

However, I’ve yet to be successful…

Purely modding the BIOS to enable Re-BAR on my capable RTX 2080. I was on the latest stable 8.02 iirc, downgraded to 4.50, now on [2-3.something] as I was trying to pass the security check that still plagues me with its presence…

So, I assume downgrading will not pass the security check [I’ve just attempted experimenting to see how it played out].

Nonetheless, I believe my issue lies with the Romflash tool [I need to download it still as I’ve bounced to various links, comments, other threads that have come to integrate with this one in unison]

Although, reading various walls of text that don’t relate to my board, going back and fourth/not assessing the process in one, rather, processing multiple methods, off the basis of [General Misc troubleshooting].

I don’t exactly have an A-B guide for the solution for this board. I certainly may have missed it as I’ve been searching and reading a multitude of threads, comments and the likes.

Therefore, I kindly ask for some clarification from a clear cutting soul who would like to enlighten me.

I modified everything I need atm.
A DXE patch to be inserted after the final DXE file of the volume under the main BIOS Image.

I can’t flash the modded BIOS.
I know this now as I’ve just recently seen comments around this.

However, it’s 05:30 currently….
which means I’m F KEN tired…

So, I’ve decided to write in for some foreign aid as I predict to occur xD

I just need a clear set of instructions going forthwith.
A bullet point comment would suffix.
pun intended
Terrible one at that

Just so I’m not directed to various redirects that may not be clear as a lot is outdated.
I was hoping to find potentially redirects for a compiled 2022 guide or 2024 updated

Regardless, great work from the dedicated guys n’ gals here.

Keep up the great work!!

I’ll be on the lookout for a reply,

Thanks everyone for your time, and of course—
your efforts to the cause.

[Fernando]

@Nameless
Welcome to the Win-Raid Forum!
Since I have a rather modern ASRock mainboard with an AMD chipset myself, I know about the problem to get a modded AMI Aptio V BIOS properly flashed. It is the mainboard manufacturer, who tries to prevent any manipulation of the BIOS by inserting a secret integrity check into the BIOS.
Did you already try to use the Flashrom/Flashprog tool (currently latest v1.3 can be found >here<)? You can find my Guide and a link within the start post of this thread. According to >this< page your mainboard model has not yet been tested.

[Girofox]

Is there even a chance to flash modded BIOS on Asus nowadays? Should be based on AMI.

I tried it with patched GOP drivers for Intel graphics on an old Asus X99 via Bios flashback, no chance. Seems like there is some checksum check maybe with encapsulated BIOS .cap files.

[Fernando]

@Girofox

Is there even a chance to flash modded BIOS on Asus nowadays?

It should be no problem, if
a) the BIOS is encapsulated (as *.CAP file) and
b) the mainboard supports the USB Flashback method.

[Nameless]

I’ve not downloaded Flash yet, It was next on the cards [has to sleep though xD}

I’m assuming that I need to flash the modded BIOS and then that’s pretty much it.
Hopefully not an oversight here…

I was cast by bewilderment though, as I followed the ASRock specific section which still left a Flash Check Failure even after using UBU, removing the Security Tag Code within.
I presumed this was due to AMI 5 architecture present on my board, V opposed to IV which was catered towards IV boards when most of the initial discussion flourished, as it started back in 14’

If my board has not been tested, I believe that it should be no different as ASRock boards have been successful from users [from what I’ve seen, yourself included on IV boards and more recent boards like your X570 iirc]
One user I seen managed successfully and they had a B450M Pro4 or B450M Pro4 R2.0, very similar boards, one a revised model facelift and the other micro-ATX scaled down version

So, at a glance I’d assume they would function identically for the most part with some variation in areas.
Even at that, my specific board could be assumed to be easier/identical as it is the original variant pertaining to the configuration of these boards [could be 110% wrong with these assumptions though xD]

I’m still not aware of the tools I specifically need to utilise here.
I have unpacked the Mega archive published by @SoniX
However, I believe I only need to use certain tools from this depending on the board and its architecture.
I wasn’t sure If I’m meant to use MMT at all or a certain version or…
Also unsure on some comments referring to the process relating to this code snippet
{ FPTW64 -bios -f mod_bios.bin },
that’s to be used along with other snippets I have seen for the same application tool and/or others that either apply to me or don’t.

Hence why I mentioned I haven’t seen/maybe missed an up-to-date post/guide that is not obsolete to my specific scenario/board due to the elapsed duration of the thread to date, and comments that relate to different boards/processes/solutions/variations on board architecture.
Likewise the tools published to tackle specific issues for each board.

I’ll stop rambling on here xD

Just want to express my position/phase in the current entanglement that’s got me in a mental chokehold currently, and hopefully, provided information that’s transparent for yourself and others to understand so that we are 1:1 or at least close in order to tackle the issue, further meeting a solution thereafter.

Thank you for the initial response @Fernando greatly appreciated, Sir

[chuckbam]

AFUWINx64.exe looks like it works but it does nothing. Secure flash error

I attempted the commands:
Afuwinx64.exe P9X79.rom /GAN
AFUWINx64.exe P9X79.rom /P /B /GAN
AFUWINx64.exe P9X79.rom /P /B /GAN /R

[MeatWar]

@chuckbam

Secure flash error

AFU /GAN doesn’t work wit CAP files renamed to ROM…

[chuckbam]

I followed the step: Open the *.CAP file, do a right-click onto the listed “AMI Aptio capsule”, choose the option “Extract body…” and save it as *.ROM file. With the UEFITool .

[Nameless]

Anyone that has modded their AM4 B450 MOBO/modified NvStarpsReBar.ffs
feel free to DM me to assist me if you are able to, thanks in advance!!

TL;DR - Is there anything different I should be using regarding Flash Programming Tool (v1.3) & any up-to-date steps/processes pertaining to this in 2025.

Again, I’m not entirely certain exactly the path to taken with my specific configuration due to the cluster of comments, updates, problems, and specific cases for specific components everyone has.

Just being ultra cautious here as a means of strictly doing what I need to do for myself so no unnecessary steps are applied to my situation.

Blockquote

• Copy the Flashrom files named flashrom.exe and CWSDPMI.EXE into the root of the just created bootable USB Flash Drive.

• Boot off the USB Flash Drive in LEGACY mode (CSM should be set within the mainboard BIOS to “ENABLED”).

• Once you have access to the DOS image, type
  flashrom -p internal -r BACKUP.ROM
  and hit the “Enter” key. Wait until the process has been finished.
  You hopefully will see something like this on your desktop screen:

• Now you can shut down your PC and remove the USB Flash Drive. Don’t forget to enter the BIOS during the next start of the PC and to restore your desired BOOT order and options.

• The just created file named BACKUP.ROM is a clean complete BIOS Region dump of your mainboard and should be stored outside of your PC to be able to recover the original BIOS Region later on, if something should go wrong at any time.

Now you should use a copy of the backup.rom file as source for the UBU work updating the desired BIOS modules.

• Once you have finished the desired UBU processing and saved the product as “BACKUP.ROM”, rename it to “MOD.ROM” and copy it onto the already previously used USB Flash Drive.

• Boot off the USB Flash Drive in LEGACY mode again, type
  flashrom -p internal -w MOD.ROM
  and hit the “Enter” key.

Now wait until the erasing, flashing and verification process has been finished.
Users, who want to get a logfile about what exactly has been checked, detected and done by the tool, should execute the command with the suffix “ -o writelog.txt” (thanks to hancor for the info).

When mentioned to use FlashPrgTool v1.3, does the commands differ to FlashRomTool here?

as for the copying the program files:

• Copy the Flashrom files named flashrom.exe and CWSDPMI.EXE into the root of the just created bootable USB Flash Drive.

is this the same process with FlashPrgTool?
I cannot find any .exe nor CWSDPMI.EXE files.
They are all H, C, SH, TMPL, RULES [file types]

[Fernando]

@Nameless
Don’t expect any support from my side regarding your problem. Since I don’t have any own experience with the usage of the new “flashprog tool”, you should better ask the tool developer for help.
After having flashed the latest original BIOS into the chip of my ASRock X570 Pro4 I am not even able to create a proper BACKUP.ROM by using the Flashrom v1.2 Utilities, which worked fine with the same system before.
Meanwhile I have given up any intention to flash a modded BIOS into this rather modern ASRock X570 chipset mainboard. I don’t want to risk a bricked system.