-- Get ovmf

http://sourceforge.net/apps/mediawiki/tianocore/index.php?title=OVMF

ovmf execute UEFI on virtual machine.
make directory named ovmf.

-- Make 4G size disk that name is rootfs.qcow2 in disk directory.
% mkdir disk
% qemu-img create -f qcow2 rootfs.qcow2 4G


-- ON nbd module.

% modprobe nbd


-- Connect disk to use nbd.
X is number.

% qemu-nbd -c /dev/nbdX disk.qcow2


-- Operate partition.
% sudo fdisk

Use g, make gpt partition table.
Use n, add new partition.

-- Make device map

% kpartx -v -a /dev/nbdX


-- Make filesystem.

% mkfs.vfat -v -c -V 32 /dev/mapper/nbdXp1


-- Mount

% mount -t vfat /dev/mapper/nbd0p1 /mnt