To generate an image for a Cubieboard2 based on the image available for the version 1.
Install ports for sysutils/u-boot and sysutils/dtb.
# pkg_add u-boot
# pkg_add dtb
Download the image for Cubieboard1 from your nearest mirror:
# ftp http://ftp.openbsd.org/pub/OpenBSD/snapshots/armv7/miniroot-cubie-60.fs
Use vnconfig to make your file appear as a disk:
# vnconfig vnd0 miniroot-cubie-60.fs
Mount the MSDOS partition and copy the dtb file for the version 2 of the board:
# mount /dev/vnd0i /mnt/vnd0i
# cp /usr/local/share/dtb/arm/sun7i-a20-cubieboard2.dtb /mnt/vnd0i
Write the U-Boot for the version 2 of the board:
# dd if=/usr/local/share/u-boot/Cubieboard2/u-boot-sunxi-with-spl.bin \
> of=/dev/rvnd0c bs=1k seek=8 conv=notrunc
Umount the partition and unconfigure the vnode disk:
# umount /dev/vnd0i
# vnconfig -u vnd0
Copy the image to the sdcard. Assuming that the sdcard appears as sd1:
# dd if=miniroot-cubie-60.fs of=/dev/rsd1c bs=1m
Insert into the board.
Done.