Using the BSP tools to create an .img that I could flash directly to the emmc from dd

I need a way to DD an image directly to the hard disk. Is there a way to build an “mmc.img” with all the partitions present?

Is there a reason you can’t use the nvidia flashing tool?

I want to boot into an initramfs kernel on the device to perform an in-the-field update. Therefore, I can’t use the 32bit tools that nvidia provides.

I am going to try to look at flash.sh, and attempt to create my own image using parted on a sparse/raw image file.

You can clone the eMMC, slicing and dicing however you wish. You can clone individual partitions, you can clone between various memory ranges, you can clone the entire eMMC as a whole. Some good information is written about this for the JTK1. The actual flash clone commands on a JTX1 are required and different from the commands for JTK1, but the whole concept of partition tables and cloning is the same. So for information in general:
http://elinux.org/Jetson/Cloning

For specific JTX1 commands:
https://devtalk.nvidia.com/default/topic/898999/jetson-tx1/tx1-r23-1-new-flash-structure-how-to-clone-/post/4784149/#4784149