I want boot my asrock h61m vg4 from nvme
Follow the guides:
[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 the MMtool method
b) NvmExpressDxe_Small.ffs dated 04/01/2018
(uncompressed size: only 6 KB, recommended for BIOSes with limited DXE Driver Volume space)
[Guide] How to flash a modded AMI UEFI BIOS - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)
Perform current system bios backup before any mods flash.