hi all . nvme on pci express adapter sometimes cannot boot OS .
but i can boot windows 10 on this nvme by using clover . i use archlinux . 1) download CloverISO-5070.tar.lzma tar xvf CloverISO-5070.tar.lzma --lzma modprobe fuse fuseiso ./Clover-v2.5k-5070-X64.iso /mnt ls /mnt EFI Library usr 2) mkdir /home/foge/clover--- cp -aR /mnt/* /home/foge/clover--- cd /home/foge/clover--- # ls EFI Library usr 3)# cd EFI/CLOVER/drivers/ #cp off/NvmExpressDxe.efi UEFI/ 4)/dev/sdb is USB memory mkfs.vfat /dev/sdb1 mount /dev/sdb1 /mb1 cp -aR /home/foge/clover---/* /mb1 umount /mb1 5)this USB memory can boot nvme on pci express (windows10). i did not try OpenBSD , but i hope this USB memory may be boot OpenBSD . -- from tuyosi takesima

