boot openbsd in UEFI pc preparing by only OpenBSD

0)i wii install openbsd to USB HDD (sd1).

1) boot PC by openbsd 5.8 snapshot CD.

2) install but Partway

3) when 'Use (W)hole disk .....' appear , push ! and go to shell .

4) fdisk -i -b 960 sd1 

 5) exit

6) when # appear ,

newfs_msdos /dev/rsd1i

mount /dev/sd1i  /mnt2

mkdir -p /mnt2/efi/boot

cp /mnt/usr/mdec/BOO* /mnt2/efi/boot

7) reboot PC 

8)the next comes up .

in BIOS

openbsd's sd1i is captured as UEFI Generic Boot

          sd1a             as Maxter 

<expieriemnt> 

and then 

i install openbsd58 into openbsd area  .

but

snapshot's UEFI cannot boot openbsd58 .

it is natural because of diffrense of virsion .