How to force external memory not init?

[Devries]

Hello,
I want to force external memory not init, there is an attribute

__NOINIT_ATTR

that can make variable not init, and there is an attribute

EXT_RAM_ATTR

that can make variable stored in the external memory, but there is not attribute to mark variable in external memory and not init, or a configure macro to set the whole external memory not init?