To make emmc, we need to boot up with SD cards.

== dd way ==



== fdisk + mkfs way==
run these two scripts:

https://git.g77k.com/yiling.cao/luna-sd-installer/blob/master/emmc_fdisksd.sh

https://git.g77k.com/yiling.cao/luna-sd-installer/blob/master/c2h2_installl_basic_upgrader.sh