Introduce the Firmware CONfiguration Framework (fconf).
The fconf is an abstraction layer for platform specific data, allowing
a "property" to be queried and a value retrieved without the requesting
entity knowing what backing store is being used to hold the data.
The default backing store used is C structure. If another backing store
has to be used, the platform integrator needs to provide a "populate()"
function to fill the corresponding C structure.
The "populate()" function must be registered to the fconf framework with
the "FCONF_REGISTER_POPULATOR()". This ensures that the function would
be called inside the "fconf_populate()" function.
A two level macro is used as getter:
- the first macro takes 3 parameters and converts it to a function
call: FCONF_GET_PROPERTY(a,b,c) -> a__b_getter(c).
- the second level defines a__b_getter(c) to the matching C structure,
variable, array, function, etc..
Ex: Get a Chain of trust property:
1) FCONF_GET_PROPERY(tbbr, cot, BL2_id) -> tbbr__cot_getter(BL2_id)
2) tbbr__cot_getter(BL2_id) -> cot_desc_ptr[BL2_id]
Change-Id: Id394001353ed295bc680c3f543af0cf8da549469
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>