Can't build -- "No rule to make target 'kernel_hooks.S'"

[netux]

Apparently Makefile doesn't have a handling for '*.S' files.

Full error:

$ make -k
# other logs
make[1]: *** No rule to make target `kernel_hooks.S', needed by `path/to/SwapDRC/swapdrc.elf'.
make[1]: *** No rule to make target `syscalls_asm.S', needed by `path/to/SwapDRC/swapdrc.elf'.
make[1]: Target `path/to/SwapDRC/swapdrc.elf' not remade because of errors.
make: *** [build] Error 2

(the -k argument makes make ignore any errors and keep building)

Looking into Makefile, and even though I don't fully understand how it works, I see what I think is a rule for '*.S' files:

%.o: %.S
	@echo $(notdir $<)
	@$(CC) -MMD -MP -MF $(DEPSDIR)/$*.d -x assembler-with-cpp $(ASFLAGS) -c $< -o $@ $(ERROR_FILTER)

My only modifications to Makefile were adding "s to allow for running make from a cwd with spaces on it's path.