donwloading source code (kernel 3.1)
git clone http://git.linaro.org/git/kernel/linux-linaro-3.1.git
trying u-boot from
git clone git://git.linaro.org/boot/u-boot-linaro-stable.git
cd u-boot-linaro-stable
make mx53loco_config
make uboot.imx
sudo dd if=u-boot.imx of=/dev/sdb bs=512 seek=2
