diff --git a/makefiles/module.mk b/makefiles/module.mk
index 8b01d0a126..154d37cc2b 100644
--- a/makefiles/module.mk
+++ b/makefiles/module.mk
@@ -75,6 +75,12 @@
 #	the list should be formatted as: 
 #		<command>.<priority>.<stacksize>.<entrypoint>
 #
+# DEFAULT_VISIBILITY	(optional)
+#
+#	If not set, global symbols defined in a module will not be visible 
+#	outside the module. Symbols that should be globally visible must be
+#	marked __EXPORT.
+#	If set, global symbols defined in a module will be globally visible.
 #
 
 #
@@ -98,11 +104,6 @@ $(error No module makefile specified)
 endif
 $(info %  MODULE_MK           = $(MODULE_MK))
 
-#
-# Get path and tool config
-#
-include $(PX4_BASE)/makefiles/setup.mk
-
 #
 # Get the board/toolchain config
 #
@@ -150,6 +151,19 @@ $(MODULE_COMMAND_FILES): $(GLOBAL_DEPS)
 	$(Q) $(TOUCH) $@
 endif
 
+################################################################################
+# Adjust compilation flags to implement EXPORT
+################################################################################
+
+ifeq ($(DEFAULT_VISIBILITY),)
+DEFAULT_VISIBILITY = hidden
+else
+DEFAULT_VISIBILITY = default
+endif
+
+CFLAGS		+= -fvisibility=$(DEFAULT_VISIBILITY) -include $(PX4_INCLUDE_DIR)visibility.h
+CXXFLAGS	+= -fvisibility=$(DEFAULT_VISIBILITY) -include $(PX4_INCLUDE_DIR)visibility.h
+
 ################################################################################
 # Build rules
 ################################################################################
diff --git a/makefiles/nuttx.mk b/makefiles/nuttx.mk
index c6e2c86d1b..e86f1370b9 100644
--- a/makefiles/nuttx.mk
+++ b/makefiles/nuttx.mk
@@ -71,5 +71,5 @@ LINK_DEPS		+= $(NUTTX_EXPORT_DIR)libs/libapps.a \
 
 $(NUTTX_CONFIG_HEADER):	$(NUTTX_ARCHIVE)
 	@$(ECHO) %% Unpacking $(NUTTX_ARCHIVE)
-	$(Q) $(UNZIP) -q -o -d $(WORK_DIR) $(NUTTX_ARCHIVE)
+	$(Q) $(UNZIP_CMD) -q -o -d $(WORK_DIR) $(NUTTX_ARCHIVE)
 	$(Q) $(TOUCH) $@
diff --git a/makefiles/setup.mk b/makefiles/setup.mk
index 8e7a00ef4c..7655872e5f 100644
--- a/makefiles/setup.mk
+++ b/makefiles/setup.mk
@@ -41,6 +41,7 @@
 # the number of duplicate slashes we have lying around in paths,
 # and is consistent with joining the results of $(dir) and $(notdir).
 #
+export PX4_INCLUDE_DIR	 = $(abspath $(PX4_BASE)/src/include)/
 export PX4_MODULE_SRC	 = $(abspath $(PX4_BASE)/src/modules)/
 export PX4_MK_DIR	 = $(abspath $(PX4_BASE)/makefiles)/
 export NUTTX_SRC	 = $(abspath $(PX4_BASE)/nuttx)/
@@ -51,24 +52,33 @@ export IMAGE_DIR	 = $(abspath $(PX4_BASE)/Images)/
 export BUILD_DIR	 = $(abspath $(PX4_BASE)/Build)/
 export ARCHIVE_DIR	 = $(abspath $(PX4_BASE)/Archives)/
 
+#
+# Default include paths
+#
+export INCLUDE_DIRS	:= $(PX4_MODULE_SRC) \
+			   $(PX4_INCLUDE_DIR)
+
+# Include from legacy app/library path
+export INCLUDE_DIRS	+= $(NUTTX_APP_SRC)
+
 #
 # Tools
 #
-MKFW			 = $(PX4_BASE)/Tools/px_mkfw.py
-UPLOADER		 = $(PX4_BASE)/Tools/px_uploader.py
-COPY			 = cp
-REMOVE			 = rm -f
-RMDIR			 = rm -rf
-GENROMFS		 = genromfs
-TOUCH			 = touch
-MKDIR			 = mkdir
-ECHO			 = echo
-UNZIP			 = unzip
+export MKFW		 = $(PX4_BASE)/Tools/px_mkfw.py
+export UPLOADER		 = $(PX4_BASE)/Tools/px_uploader.py
+export COPY		 = cp
+export REMOVE		 = rm -f
+export RMDIR		 = rm -rf
+export GENROMFS		 = genromfs
+export TOUCH		 = touch
+export MKDIR		 = mkdir
+export ECHO		 = echo
+export UNZIP_CMD	 = unzip
 
 #
 # Host-specific paths, hacks and fixups
 #
-SYSTYPE			:= $(shell uname -s)
+export SYSTYPE		:= $(shell uname -s)
 
 ifeq ($(SYSTYPE),Darwin)
 # Eclipse may not have the toolchain on its path.
diff --git a/src/include/visibility.h b/src/include/visibility.h
new file mode 100644
index 0000000000..2c6adc062e
--- /dev/null
+++ b/src/include/visibility.h
@@ -0,0 +1,62 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file visibility.h
+ *
+ * Definitions controlling symbol naming and visibility.
+ *
+ * This file is normally included automatically by the build system.
+ */
+
+#ifndef __SYSTEMLIB_VISIBILITY_H
+#define __SYSTEMLIB_VISIBILITY_H
+
+#ifdef __EXPORT
+#  undef __EXPORT
+#endif
+#define __EXPORT __attribute__ ((visibility ("default")))
+
+#ifdef __PRIVATE
+#  undef __PRIVATE
+#endif
+#define __PRIVATE __attribute__ ((visibility ("hidden")))
+
+#ifdef __cplusplus
+#  define __BEGIN_DECLS		extern "C" {
+#  define __END_DECLS		}
+#else
+#  define __BEGIN_DECLS
+#  define __END_DECLS
+#endif
+#endif
\ No newline at end of file