F2A85-V-6605-NVME.rar (6.3 MB)
Try this, I had inserted the “NvmExpressDxe_5.ffs” by the way in this guide. At least it works for me with the b85 motherboard.
[HowTo] Get full NVMe Support for all Systems with an AMI UEFI BIOS - Special Topics / NVMe Support for old Systems - Win-Raid Forum (level1techs.com)
Try to flash the .cap file with asus original flasher, or flash the .rom file with AFUDOS or AFUWIN Tool as the guide said.
[Guide] How to flash a modded AMI UEFI BIOS - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)