What is the recommended way to pull in the DTB device-tree (and overlays) while using uboot for loading the aarch64 kernel:
1. Have the Raspberry Pi firmware pass it to uboot (via the uboot variable "fdt_addr") then pass that to the kernel via the booti line.
2. The way it's currently set up: Have uboot load the DTB file itself (into the uboot variable " fdt_addr_r") which is then passed to the kernel via booti line.
The reason I ask is because with the way it currently is, you can't use config.txt to load overlays and set dtparams. This is because uboot is ignoring the resulting DTB that the Pi firmware makes from the config.txt (with the dtparams and overlays and such). Because of this, you can't load overlays or set dtparams. If anyone has an explanation, I'd appreciate it, thanks.
EDIT: I guess you can technically load overlays via uboot, but it's a little more messy than using config.txt. it involves loading both the base DTB and the overlay into different variables and applying the overlay over the base and passing it to the kernel. You have to be careful with sizing and the offset and stuff. It is much easier to use config.txt