To upload Nebula v3 to your Nbox make sure that you have B4T uboot preinstalled or duo multi uboot.
If you using duo multi uboot change to B4T uboot.
How to install nebula using B4T uboot?
You need:
Pendrive formatted to FAT32
File with Nebula v3
File update which can be found attached to this post.
Extract the files to the penstick from http://linuxsat-support.com/nb…v3-nbox-5800s-5800sx.html and from the update file found attached to this post.
You should have on teh root directory of you drive 3 files
rootfs.img
uImage
update
Put your Pendrive into the receivers USB slot . Connect power supply and when you see "nBox" on the nbox front display pressarrow up and go to UPDATE than press OK.
Wait until screen shows OK. Disconnect power supply and connect again. Pressing arrow up so it shows Nand and press OK. Nebula will then start.
Thanks to Euro Trans for the Original post this guide was taken from.