Structure FIT package for custom device tree overlay unpacking

[lionsheart-git]

Hey, I am trying to figure out how to best handle device tree overlays for custom FPGA IP cores on PolarFire SoC. I understand that I

1. first have to create the .dtso files by hand
2. before compiling them to .dtbo using the device tree compiler.

Looking at the custom u-boot-mchp code I can see that the design_overlays function seems to be trying to dynamically load a set of device tree blobs that somehow are extracted from the SPI flash present on all development kits.

What I do not understand is how I embed the blobs in the FIT image, meaning the structure that is following the four magic "MCHP" numbers, and how the programs where from to load the blob. If someone could help clarify this I would greatly appreciate it!

[hughbreslin]

Hey @lionsheart-git you could try this method of just loading them at runtime using a script (or calling the commands), have a look at overlay.sh in here - you could just compile the dtbo on the device and apply after linux has booted