Dear Martin, Sorry, I forgot to ask one thing. > As Ben pointed out, it's the same kernel. Now I understand it's the same kernel, only need flash-kernel to build the boot image (add ID or DTB, etc). But I have no idea how initrd/initramfs for d-i get built. I guess there're some scripts in some repo. It'd be very helpful if you can provide those info. Thank you! Cheers, Roger