I want to boot linux by QEMU with coreboot ,and I have some problems in making Linux image. 
I followed the steps on QEMU Build Tutorial form coreboot.org.

As the Creating a hard disk image section points out: 

1.qemu-img create -f raw disk.img 200M
2.mkfs.ext2 -F disk.img 
3.mkdir /mnt/rootfs
4. mount -o loop disk.img /mnt/rootfs
5.mkdir /mnt/root/boot
6.cp vmlinux /mnt/rootfs/boot/vmlinuz
7.cp initrd.img /mnt/rootfs/boot/initrd
8.cp -R /* /mnt/rootfs 

I've done all the steps above, but the image doesn't work on QEMU.

What does the 8th step mean? Does it act as filesystem?
If so, could I only copy the directories and the root filesystem to make it work? 

I want to know how to build the image.
P.S. my Linux distribution is ubuntu 14.04

Many thanks.