You cannot flash a modded ASUS BIOS by using the standard ASUS EZ Flash tool.
If your mainboard offers this feature, it will work (provided, that you have followed ASUS’s USB Flashback guide and rules).
Tip: Use another USB Flash Drive (preferentially an old 2.0 platform and small sized one).
Just follow the advices of the start post. We cannot do the flashing procedure for you.
A post was split to a new topic: [Request] How to unlock an ASUS ROG Crosshair VIII Hero (WiFi) BIOS?
Has anyone succeeded loading a modified BIOS to a Supermicro H12 board? I’m running a H12SSL.
Supermicros tool & BMC does not allow flashing the modded BIOS, which I guess is expected. I understand that I should try one of AMIs tools, but which one? The Bios screen version says “12.21.1280, 2022, AMI” if that’s any help.
Thanks!
@jcie Welcome to the Win-RAID Forum!
If you are not able to get the modded BIOS successfully flashed the normal way (by using the Supermicro tool after having renamed the modded BIOS), I recommend to read >this< post written by our Forum member Wishbringer.
Good luck!
Dieter (alias Fernando)
A post was merged into an existing topic: [HowTo] Get full NVMe Support for all Systems with an AMI UEFI BIOS
Hello, my thanks for the effort of writing and maintaining this guide and the forum in general.
I am trying to get NVMe Support on my ASUS p8z77-m.
What I have managed until now:
The resulting *.CAP file is of course not passing the security verification in EZFlash and in Asus BUPDATER_130 (DOS flasher). But that is expected. My question: Is it safe to flash this modded *.CAP file with ASUS AI Suite (as described in the flashing guide)?
If I understand it well, the guide states that I should proceed with the extraction of the *.ROM from the original *.CAP file, and than mod that with the UEFITool to add the NvmExpressDxe_5.ffs
I’d rather skip this if the option of flashing the unverifiable *.CAP file is possible (and safe) with ASUS AI Suite.
Shouldn’t this be the default (and easiest) option for flashing Asus *.CAP bioses - or am I missing something? I was reading and rereading the modding/flashing guides for several days now, and as I understand the main problem with the Asus *.CAP files is the security protection/verification. This flashing with ASUS AI Suite seems easiest, and it skips several steps - which are quite confusing even after so much reading (the extraction of the body of the bios, etc).
Thanks @Fernando
I wasn’t sure which of the 2 threads was more appropriate, as I am asking about both the modding and flashing.
I am not sure if understood the guide. Is it “safe” to mod the protected Asus *.CAP bioses with MMTool. Or do I have to mod *.CAP bioses with UEFITool?
It seems to me that the main problem with the Asus *.CAP files is the security protection/verification which disables flashing a modded bios. So UEFITool is used to extract/convert to *.ROM and mod/flash that. But since flashing with ASUS AI Suite bypasses the security verification (with the file switching in mid process), isn’t that and modding with MMTool the easier option?
@van
Its safe, if your modding an Asus bios update CAP file and you’re gonna use it ONLY in a motherboard with USB BFB feature, that the P8Z77-M has it.
The Asus CAP files will update the bios region (Only one usually) and will preserve the board original data as DMI, MAC etc…
So for simple insertion of NVMe DXE, the USB BFB feature using CAP is enough and the most secure/successful.
Indeed some “leaked” versions of the MM tool/AMIBCP tool can break the signature.
This happens more on AMI Aptio V core bioses, yours a IV.
Now the use of CAP files is not only for motherboards with USB BFB feature, others dont have it, so for those the internal Asus EZ Flash cant use these “broken” mod cap files, this is where we need to extract and later replace the bios region as mod, to the original CAP file.
Thanks @MeatWar.
So I wrongly thought that even with the USB BFB the ROM extraction/replacement is a must do in all ASUS cases. I am glad that is not the case.
So in retrospect:
But I digress. I will do it ether way, I just wanted to ask what is safe and what is not. Thank you.
@Fernando may I suggest to consider MeatWar’s post to be added to the main/first post. The current explaination is not very clear on this point, e.g. precisely when ROM extraction/replacment is needed and when it is not.
Blockquote
Its safe, if your modding an Asus bios update CAP file and you’re gonna use it ONLY in a motherboard with USB BFB feature, that the P8Z77-M has it.
The Asus CAP files will update the bios region (Only one usually) and will preserve the board original data as DMI, MAC etc…
So for simple insertion of NVMe DXE, the USB BFB feature using CAP is enough and the most secure/successful.
Indeed some “leaked” versions of the MM tool/AMIBCP tool can break the signature.
This happens more on AMI Aptio V core bioses, yours a IV.
Now the use of CAP files is not only for motherboards with USB BFB feature, others dont have it, so for those the internal Asus EZ Flash cant use these “broken” mod cap files, this is where we need to extract and later replace the bios region as mod, to the original CAP file.
No, i cant agree on this… definitely AI Suite not the BEST/EASY or Secure way to flash a mod…this is an alternative to trick the app (Asus CAPSULE sig) on boards without USB BFB and that cant use EZ flash due to fail security (its a mod…), so please use this feature and NOT AI Suite.
A side spare USB with an original CAP file and a backup of the current bios region made with FPT tool, is all you need to ensure you can recover the board and the original data.
Why this statement… because you’re running a critical operation in an system using resources and already running an OS environment with a lot of processes in the background, the chances of interference in this process are much higher and risky than EFI shell/DOS or USB BFB.
I see. OK, got it… USB BFB it is then. 
Thanks. Will report the outcome later.
Reporting success.
Regarding the flashing process, it went smoothly - once I found the right usb flash (and I had to go through several usb flash drives to find it).
It seems the recommendation to use flash drive that hadn’t been formated with multiple partitions in the past, was a good advice. I tryout many linux distros and live bootable usb utilities, so I guess that was the culprit with the other usb’s. Those usb flash drives, even when re-partitioned in single partition and fat32 formated, they didn’t work with the Asus usb BFB. And for the record, I tried only 2.0 sticks with as small as possible sizes (and fat32 formatted, ofc).
I have many usb drives but in the end I had to borrow my wife’s document usb. That 8GB stick did the job. 
My thanks for the help @MeatWar, and thanks to everybody else who contributed advice and experiences in the thread/forum.
Thanks for the guide! I was able to flash a modded .ROM on my X99 Deluxe using AFUWINx64. For some reason I was not able to use the flashback feature with the renamed .CAP, but that’s ok. Anyway, bifurcation is working now and successfully flashed.
Hi, I am new to any of this.
I have Asus Tuf Gaming FX705GE, where I want to flash my custom BIOS image which I am unsuccessful of. I am using AFUWINGUIx64, I open my Custom IMAGE and do FLASH. And it shows 18 - Error: Unable to start a secure flash session.
Any ideas?
Thanks/.
@Zorro
Welcome to the Win-RAID Forum!
Please read carefully the ASUS BIOSes related chapter of this thread’s first post and follow the advices.
Good luck!
Dieter (alias Fernando)
Hello,
Thank you for your reply.
I viewed all possible ways to flash Modded BIOS on my Asus Laptop. Most of them are not possible due to limited hardware and software support. I end up using AmiWin method, which still did not work and result to same issue. Unable to start a secure flash session.
I looked over for possible issue solution and couldn’t figure anything out. Is there anything else that could help me?
Standard methods usually are not viable for mod files, due to security preventing flashing modified firmwares…well know issue on mod community.
An alternative for Intel based machines…
[GUIDE] [UPDATE] Usage of AMI’s AptioV UEFI Editor + FPT Flash Method - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)
the main issue here is the actual state of SPI regions access, described here:
[Guide] Unlock Intel Flash Descriptor Read/Write Access Permissions for SPI Servicing - Special Topics / Intel Management Engine - Win-Raid Forum (level1techs.com)
A note…this tool (Intel FPT) doesnt care of the content of the files, it flashes all bad or not.
The users should only engage in this process if they know how to recover the system and have done SPI backups, of course they should be a little experienced on this…not a task for 1rst time users.
Thank you very much for this. Seems like I succeeded to flash. Thank you again.