U-Boot with direct NVMe boot support for eMMC/SPI Flash

[fretinator]

Is there any update on this? Is there a guide somewhere with the latest/most functional uboot and how to flash it properly? Now I only seem to get some bits and pieces from different places.

Here is how I did it.

I ran the SPI mentioned from the command-line from eMMC. 
I used Manjaro and booted the version with emmc install support from an SD card. I chose the NVME drive as the destination.
I opened the device and flipped the eMMC switch to off.
Voila!

I didn't do performance test, but my user test was to go to a graphics heavy sight and scroll. On the eMMC it was noticeably laggy when scrolling. On the NVME it is much smoother scrolling.