Botched eMMC boot file

[rdfong]

Hi I was having trouble getting my UART ports enabled and so was playing with the neo plus 2 dtb files in /boot which resulted in me messing up my boot file and now I am stuck in U-boot. My current ubuntu setup is installed on the eMMC.

I am trying to find a way to access my dtb file since I made a back up and then reset it. I'm trying to do this by loading an image onto an SD card, plugging in the SD card and then accessing the eMMC as storage and doing what I need to do to fix stuff.

However, when I plug in the Sd card and try to boot, nothing happens. No flashing lights, nothing. If I load on eflasher to the SD card that seems to work, but re-flashing everything on my eMMC is definitely not at all an option. Any ideas what might be going wrong and if there is a solution from u-boot to forcefully boot from the SD card? (I've never touched U-Boot in my life)

[rdfong]

Alternatively does anyone know of something light weight that I can flash onto my SD card sort of like eFlasher with terminal tools but not for the purpose of just flashing the eMMC but rather to access the eMMC as storage and write stuff to it?

Thanks!