including assamble file '.s' (lowercase) in a project

Hello

I need to use a '.s' file in a arduino project. I included it into "cores" folder:

...\Arduino15\packages\arduino\hardware\samd\1.6.6\cores\

but i compile arduino and the '.s' cannot be read by gnu gcc.

I think "recipe" in platform.txt cannot read that '.s' file :

##############################################################

compiler.S.cmd=arm-none-eabi-gcc
compiler.S.flags=-c -g -x assembler-with-cpp

###############################################################

Compile S files

recipe.S.o.pattern="{compiler.path}{compiler.S.cmd}" {compiler.S.flags} -DF_CPU={build.f_cpu} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} {compiler.S.extra_flags} {build.extra_flags} {compiler.arm.cmsis.path} {includes} "{source_file}" -o "{object_file}"
################################################################

the problem is the new '.s' file, in its comments, demand to be read by gnu as.

what can i do? continue trying with gnu gcc? how can i change to be read only by gnu as?

thanks

You are aware that a .s and a .S file are not the same thing, right?

Naming convention:
.S = user-written code
.s = machine generated code (e.g gcc -S ...)