[TF-A] The increasing size of BL31

Hi,

Typically, BL31 runs in SRAM which tends to be limited. As we add support for newer architectural features e.g. CCA, general features and standards, the size of BL31 image will grow and become harder to fit in most SRAMs.

This email is to share ideas on how to address this problem.

A simple approach will be to identify parts of NOBITS ELF sections of BL31 which can be moved out to DRAM. Since NOBITS sections aren't part of the file image, loading and authentication code doesn't have to change. The challenge will be to come up with some criteria to help decide what kind of buffers can be kept in DRAM vs SRAM.

Other ideas are also welcome. Please share your thoughts.

Thanks, Okash