[make] add options to add extra .o files to the link line at the module and global scope

make/build.mk

@@ -6,10 +6,10 @@ $(OUTBIN): $(OUTELF)
 	$(NOECHO)$(SIZE) $<
 	$(NOCOPY)$(OBJCOPY) -O binary $< $@
 
-$(OUTELF): $(ALLMODULE_OBJS) $(LINKER_SCRIPT)
+$(OUTELF): $(ALLMODULE_OBJS) $(EXTRA_OBJS) $(LINKER_SCRIPT)
 	@echo linking $@
 	$(NOECHO)$(SIZE) -t $(ALLMODULE_OBJS)
-	$(NOECHO)$(LD) $(GLOBAL_LDFLAGS) -T $(LINKER_SCRIPT) $(ALLMODULE_OBJS) $(LIBGCC) -o $@
+	$(NOECHO)$(LD) $(GLOBAL_LDFLAGS) -T $(LINKER_SCRIPT) $(ALLMODULE_OBJS) $(EXTRA_OBJS) $(LIBGCC) -o $@
 
 $(OUTELF).sym: $(OUTELF)
 	@echo generating symbols: $@

make/module.mk

@@ -12,6 +12,7 @@
 # MODULE_CPPFLAGS : CPPFLAGS local to this module
 # MODULE_ASMFLAGS : ASMFLAGS local to this module
 # MODULE_SRCDEPS : extra dependencies that all of this module's files depend on
+# MODULE_EXTRA_OBJS : extra .o files that should be linked with the module
 
 # MODULE_ARM_OVERRIDE_SRCS : list of source files, local path that should be force compiled with ARM (if applicable)
 
@@ -67,7 +68,7 @@ include make/compile.mk
 
 # build a ld -r style combined object
 MODULE_OBJECT := $(call TOBUILDDIR,$(MODULE_SRCDIR).mod.o)
-$(MODULE_OBJECT): $(MODULE_OBJS)
+$(MODULE_OBJECT): $(MODULE_OBJS) $(MODULE_EXTRA_OBJS)
 	@$(MKDIR)
 	@echo linking $@
 	$(NOECHO)$(LD) -r $^ -o $@
@@ -95,6 +96,7 @@ MODULE_CFLAGS :=
 MODULE_CPPFLAGS :=
 MODULE_ASMFLAGS :=
 MODULE_SRCDEPS :=
+MODULE_EXTRA_OBJS :=
 MODULE_CONFIG :=
 MODULE_OBJECT :=
 MODULE_ARM_OVERRIDE_SRCS :=

makefile

@@ -82,6 +82,9 @@ EXTRA_BUILDDEPS :=
 # any rules you put here will be depended on in clean builds
 EXTRA_CLEANDEPS := 
 
+# any objects you put here get linked with the final image
+EXTRA_OBJS :=
+
 include project/$(PROJECT).mk
 include target/$(TARGET)/rules.mk
 include platform/$(PLATFORM)/rules.mk