+# This incantation ensures that changes to any subarch asm files will
+# force the corresponding object file to be rebuilt, even if the implicit
+# rule below goes indirectly through a .sub file.
+define mkasmdep
+$(dir $(patsubst %/,%,$(dir $(1))))$(notdir $(1:.s=.o)): $(1)
+endef
+$(foreach s,$(wildcard src/*/$(ARCH)*/*.s),$(eval $(call mkasmdep,$(s))))
+
+%.o: $(ARCH)$(ASMSUBARCH)/%.sub
+ $(CC) $(CFLAGS_ALL_STATIC) -c -o $@ $(dir $<)$(shell cat $<)