Clarification on Memory Regions and Fill Parameters in FVP_Base_RevC-2xAEMvA

Hello,

I am using the FVP_Base_RevC-2xAEMvA model and examining the memory initialization parameters related to different memory regions (e.g., bp.dmc, bp.ns_dram, etc.). Running the command --list-params yields the following fill-related parameters:

```shell
bp.dmc.fill1=3755990991 # Fill pattern 1, initializes memory with alternating fill1, fill2 pattern bp.dmc.fill2=3487555551 # Fill pattern 2 bp.ns_dram.fill1=3755990991 bp.ns_dram.fill2=3487555551 ... (similar for other regions like bp.psram, bp.rt_dram, etc.)
 ```

I would like to understand the scope and application of these parameters:

  1. What is the specific role of each memory region (e.g., bp.dmc, bp.ns_dram, bp.rt_dram, etc.) in the context of the simulation?
  2. Are there specific use cases or interactions that determine when to configure these different regions and their respective fill patterns?
  3. Do all these regions serve independent purposes, or are some of them interrelated?

I have confirmed that there memory region is controlled by bp.s_dram, I got this answer by try one by one. But I don't know why. In my guess, this may be related to the security of memory region. The manner says that `P` security memory region block any access from Secure and Non-secure, maybe any region that block Non-secure is controlled by bp.s_dram?

I appreciate any clarification or documentation references that can help explain how these parameters govern memory initialization.

Thank you!