[Hafnium] Boot arguments for S-EL1 with SPMC at S-EL2

Hi Olivier,

I'm trying to implement a relocatable OP-TEE binary so it can be loaded at different physical addresses without the need to recompile it. This means that in the case with Hafnium when changing "load-address" or "entrypoint-offset" in the OP-TEE SP manifest there's no need to recompile OP-TEE. For this to work OP-TEE must be able to figure out which memory range it's supposed to reside in. Currently, OP-TEE knows the entry point address from PC and "memory size" from X0. However, the "memory size" is from the "load-address" so "entrypoint-offset" must be subtracted from PC in order to know the allocated memory range.

Do you have ideas on how OP-TEE at runtime can determine the allocated memory range?

Thanks, Jens