Getting the Morello DTB upon entry to EL3

Hi,

How to I retrieve the location of the DTB from the firmware upon entry to EL3?

I'm running a small kernel, entering at EL3. The kernel is loaded into memory using the llvm toolchain make-bm script https://git.morello-project.org/morello/llvm-project-releases/-/blob/morello/baremetal-release-1.7/make-bm-image.sh?ref_type=heads. I run both on the morello board and the FVP.