arch/x86: document CAR symbols and expose them in symbols.h

Attempt to better document the symbol usage in car.ld for
cache-as-ram usage. Additionally, add _car_region_[start|end]
that completely covers the entire cache-as-ram region. The
_car_data_[start|end] symbols were renamed to
_car_relocatable_data_[start|end] in the hopes of making it
clearer that objects within there move. Lastly, all these
symbols were added to arch/symbols.h.

Change-Id: I1f1af4983804dc8521d0427f43381bde6d23a060
Signed-off-by: Andrey Petrov <>
Signed-off-by: Aaron Durbin <>
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <>
Reviewed-by: Furquan Shaikh <>
5 files changed