Preloader issue with altera 13.0

hello

I'm trying to build entire linux image(preloader, bootloader, kernel ...etc)for DE1-Soc board.

first I thought I should understand the whole booting sequence, I planned to boot only preloader first.

I made preloader-mkpimage.bin by altera 13.0 EDS BSP editor, and used dd command to copy preloader binary to sd card.

(my host computer is window 7 , so I made preloader-mkpimage on window, and used dd command on ubuntu virtual machine)

the sd card initially has one partition with id W95 FAT32

the command was : sudo dd if=preloader-mkpimage.bin of=/dev/sdX bs=64k seek=0.

But I don't see any terminal message so it seems not working ..

what I tried to experiment is simple

1. write preloader image to sd card and see if board only boots preloader.

..

I guess the problem is preloader image is not valid although it has mkpimage signature.

but preloader is generated by altera tools and I want to believe the preloader binary is fine ..

I'm really struck here,, any advice?

thanks in advance.