diff --git a/Makefile.Android.mk b/Makefile.Android.mk
index 5686726..dab9cc1 100644
--- a/Makefile.Android.mk
+++ b/Makefile.Android.mk
@@ -5,7 +5,7 @@ PROJECT_PACKAGE=$(PROJECT_NAME)package
 USER_PACKAGES += $(EWOL_FOLDER)/Sources/
 TARGET_OS = Android
 TARGET_ARCH = ARM
-CROSS = $(PROJECT_NDK)/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/arm-linux-androideabi-
+TARGET_CROSS = $(PROJECT_NDK)/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/arm-linux-androideabi-
 
 
 #Add the basic element abstraction of ewol lib
diff --git a/Makefile.Windows.mk b/Makefile.Windows.mk
index 4f4e7ac..ef8306e 100644
--- a/Makefile.Windows.mk
+++ b/Makefile.Windows.mk
@@ -4,6 +4,6 @@ USER_PACKAGES += $(EWOL_FOLDER)/Sources/
 # defien the target OS of this system
 TARGET_OS=Windows
 # define the cross compilateur
-CROSS=i586-mingw32msvc-
+TARGET_CROSS=i586-mingw32msvc-
 
 include $(EWOL_FOLDER)/Build/core/main.mk
diff --git a/core/config.mk b/core/config.mk
index fc7aa79..d521c5d 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -11,10 +11,11 @@ CONF := KCONFIG_NOTIMESTAMP=1 $(call fullpath,$(BUILD_SYSTEM)/conf)
 QCONF := KCONFIG_NOTIMESTAMP=1 $(call fullpath,$(BUILD_SYSTEM)/qconf)
 
 # Directory where original configurations are stored
-CONFIG_ORIG_DIR := $(TOP_DIR)/config-ymm
+CONFIG_ORIG_DIR := $(TARGET_CONFIG_DIR)
 
 # File where global configuration is stored
 CONFIG_GLOBAL_FILE := $(CONFIG_ORIG_DIR)/global.config
+-include $(CONFIG_GLOBAL_FILE)
 
 ###############################################################################
 ## Begin conf/qconf by copying configuration file to a temp .config file.
diff --git a/core/defs.mk b/core/defs.mk
index 7e0b49f..fd1a0d9 100644
--- a/core/defs.mk
+++ b/core/defs.mk
@@ -12,6 +12,12 @@
 empty :=
 space := $(empty) $(empty)
 space4 := $(space)$(space)$(space)$(space)
+true := T
+false :=
+
+# Return negation of argument.
+# $1 : input boolean argument.
+not = $(if $1,$(false),$(true))
 
 # Return the first element of a list.
 # $ 1 : input list.
@@ -52,6 +58,16 @@ check-pwd-is-top-dir = \
 	$(if $(patsubst $(TOP_DIR)%,%,$(shell pwd)), \
 		$(error Not at the top directory))
 
+# Compare 2 strings for equality.
+# $1 : first string.
+# $2 : second string.
+streq = $(if $(filter-out xx,x$(subst $1,,$2)$(subst $2,,$1)x),$(false),$(true))
+
+# Compare 2 strings for inequality.
+# $1 : first string.
+# $2 : second string.
+strneq = $(call not,$(call streq,$1,$2))
+
 ###############################################################################
 ## Modules database.
 ## For each module 'mod', __modules.mod.<field> is used to store
@@ -99,8 +115,11 @@ modules-LOCALS += SHARED_LIBRARIES
 # Used as dependencies to trigger indirect build.
 modules-LOCALS += EXTERNAL_LIBRARIES
 
+# General libraries to add in dependency based on their actual class (STATIC/SHARED/EXTERNAL).
+modules-LOCALS += LIBRARIES
+
 # Additional include directories to pass into the C/C++ compilers
-# Format : <fullpath>
+# Format : <fullpath> (-I will be prepended automatically)
 modules-LOCALS += C_INCLUDES
 
 # Additional flags to pass into the C or C++ compiler
@@ -143,6 +162,12 @@ modules-LOCALS += EXPORT_PREREQUISITES
 # Module class : STATIC_LIBRARY SHARED_LIBRARY EXECUTABLE
 modules-LOCALS += MODULE_CLASS
 
+# List of files to copy
+# Format <src>:<dst>
+# src : source (relative to module path)
+# dst : destination (relative to staging dir)
+modules-LOCALS += COPY_FILES
+
 # Other variables used internally
 modules-LOCALS += BUILD_MODULE
 modules-LOCALS += STAGING_MODULE
@@ -176,17 +201,48 @@ modules-dump-database = \
     ) \
     $(info --- end of modules list)
 
+# This will only dump dependencies
+modules-dump-database-depends = \
+	$(foreach __mod,$(__modules), \
+		$(info $(__mod):) \
+		$(info $(space4)$(strip $(__modules.$(__mod).depends))) \
+	)
+
 ###############################################################################
 ## Add a module in the build system and save its LOCAL_xxx variables.
-## $1 : name of module to add. All LOCAL_xxx variables will be saved in
-## module database.
+## All LOCAL_xxx variables will be saved in module database.
 ###############################################################################
 module-add = \
-  $(eval __modules += $1) \
+	$(eval LOCAL_MODULE := $(strip $(LOCAL_MODULE))) \
+	$(if $(LOCAL_MODULE),$(empty), \
+		$(error $(LOCAL_PATH): LOCAL_MODULE is not defined)) \
+	$(eval __mod := $(LOCAL_MODULE)) \
+	$(if $(call is-module-registered,$(__mod)), \
+		$(eval __path := $(__modules.$(__mod).PATH)) \
+		$(error $(LOCAL_PATH): module '$(__mod)' already registered at $(__path)) \
+	) \
+	$(eval __modules += $(__mod)) \
   $(foreach __local,$(modules-LOCALS), \
-    $(eval __modules.$1.$(__local) := $(LOCAL_$(__local))) \
+		$(eval __modules.$(__mod).$(__local) := $(LOCAL_$(__local))) \
   )
 
+###############################################################################
+## Check that a module is registered.
+## $1 : module to check.
+###############################################################################
+is-module-registered = \
+	$(strip $(foreach __mod,$(__modules), \
+		$(if $(call streq,$(__mod),$1),$(true)) \
+	))
+
+###############################################################################
+## Check that a module wil be built.
+## $1 : module to check.
+###############################################################################
+is-module-in-build-config = \
+	$(if $(CONFIG_BUILD_$(call get-define,$1)),$(true))
+
+
 ###############################################################################
 ## Restore the recorded LOCAL_XXX definitions for a given module. Called
 ## for each module once they have all been registered and their dependencies
@@ -199,15 +255,115 @@ module-restore-locals = \
     )
 
 ###############################################################################
-## Used to recompute all dependencies once all module information has been
+## Used to check all dependencies once all module information has been
+## recorded.
+###############################################################################
+
+# Check dependencies of all modules
+modules-check-depends = \
+	$(foreach __mod,$(__modules), \
+		$(call __module-check-depends,$(__mod)) \
+	)
+
+# Check dependency of a module
+# $1 : module name.
+__module-check-depends = \
+	$(foreach __lib,$(__modules.$1.depends), \
+		$(if $(call is-module-registered,$(__lib)),$(empty), \
+			$(eval __path := $(__modules.$1.PATH)) \
+			$(if $(call is-module-in-build-config,$1), \
+				$(error $(__path): module '$1' depends on unknown module '$(__lib)'), \
+				$(warning $(__path): module '$1' depends on unknown module '$(__lib)') \
+			) \
+		) \
+	) \
+	$(call __module-check-libs-class,$1,WHOLE_STATIC_LIBRARIES,STATIC_LIBRARY) \
+	$(call __module-check-libs-class,$1,STATIC_LIBRARIES,STATIC_LIBRARY) \
+	$(call __module-check-libs-class,$1,SHARED_LIBRARIES,SHARED_LIBRARY) \
+
+# $1 : module name of owner.
+# $2 : dependency to check (WHOLE_STATIC_LIBRARIES,STATIC_LIBRARIES,SHARED_LIBRARIES).
+# $3 : class to check (STATIC_LIBRARY,SHARED_LIBRARY)
+__module-check-libs-class = \
+	$(foreach __lib,$(__modules.$1.$2), \
+		$(call __module-check-lib-class,$1,$(__lib),$3) \
+	)
+
+# Check that a dependency is of the correct class
+# $1 : module name of owner.
+# $2 : library to check.
+# $3 : class to check (STATIC_LIBRARY,SHARED_LIBRARY)
+__module-check-lib-class = \
+	$(if $(call strneq,$(__modules.$2.MODULE_CLASS),$3), \
+		$(eval __path := $(__modules.$1.PATH)) \
+		$(if $(call is-module-in-build-config,$1), \
+			$(error $(__path): module '$1' depends on module '$2' which is not of class '$3'), \
+			$(warning $(__path): module '$1' depends on module '$2' which is not of class '$3') \
+		) \
+	)
+
+###############################################################################
+## Used to make some internal checks.
+###############################################################################
+
+# Check variables of all modules
+modules-check-variables = \
+	$(foreach __mod,$(__modules), \
+		$(call __module-check-variables,$(__mod)) \
+	)
+
+# Check variables of a module
+# $1 : module name.
+__module-check-variables = \
+	$(call __module-check-src-files,$1) \
+	$(call __module-check-c-includes,$1)
+
+# Check that all files listed in LOCAL_SRC_FILES exist
+# $1 : module name.
+__module-check-src-files = \
+	$(eval __path := $(__modules.$1.PATH)) \
+	$(foreach __file,$(__modules.$1.SRC_FILES), \
+		$(if $(wildcard $(__path)/$(__file)),$(empty), \
+			$(warning $(__path): module '$1' uses missing source file '$(__file)') \
+		) \
+	)
+
+# Check that all directory listed in LOCAL_C_INCLUDES exist
+__module-check-c-includes = \
+	$(eval __path := $(__modules.$1.PATH)) \
+	$(foreach __inc,$(__modules.$1.C_INCLUDES), \
+		$(eval __inc2 := $(patsubst -I%,%,$(__inc))) \
+		$(if $(wildcard $(__inc2)),$(empty), \
+			$(warning $(__path): module '$1' uses missing include '$(__inc2)') \
+		) \
+	)
+
+###############################################################################
+## Used to compute all dependencies once all module information has been
 ## recorded.
 ###############################################################################
 
 # Compute dependencies of all modules
-modules-compute-dependencies = \
+modules-compute-depends = \
     $(foreach __mod,$(__modules), \
-    	$(eval __modules.$(__mod).depends := ) \
+		$(eval __modules.$(__mod).depends := $(empty)) \
+		$(call __module-update-depends,$(__mod)) \
         $(call __module-compute-depends,$(__mod)) \
+	)
+
+# Update dependecies of a single module.
+# It updates XXX_LIBRARIES based on LIBRARIES and actual dependency class.
+# $1 : module name.
+__module-update-depends = \
+	$(foreach __lib,$(__modules.$1.LIBRARIES), \
+		$(eval __class := $(__modules.$(__lib).MODULE_CLASS)) \
+		$(if $(call streq,$(__class),STATIC_LIBRARY), \
+			$(eval __modules.$1.STATIC_LIBRARIES += $(__lib)), \
+			$(if $(call streq,$(__class),SHARED_LIBRARY), \
+				$(eval __modules.$1.SHARED_LIBRARIES += $(__lib)), \
+				$(eval __modules.$1.EXTERNAL_LIBRARIES += $(__lib)) \
+			) \
+		) \
     )
 
 # Compute dependencies of a single module
@@ -254,7 +410,7 @@ module-get-listed-autoconf = \
     ))
 
 ###############################################################################
-## Dependecy management
+## Dependency management
 ###############################################################################
 
 # Return list all the <local-type> modules $1 depends on transitively.
@@ -269,12 +425,11 @@ module-get-all-dependencies = \
 
 # Recursively get dependency of a modules
 __modules-get-closure = \
-	$(eval __closure_deps  := $(strip $1)) \
-	$(if $(__closure_deps), \
-		$(eval __closure_wq    := $(__closure_deps)) \
-		$(eval __closure_field := $(strip $2)) \
-		$(call __modules-closure)) \
-	$(__closure_deps) \
+	$(eval __closure_deps := $(empty)) \
+	$(eval __closure_wq := $(strip $1)) \
+	$(eval __closure_field := $(strip $2)) \
+	$(if $(__closure_wq), $(call __modules-closure)) \
+	$(strip $(__closure_deps))
 
 # Used internally by modules-get-all-dependencies. Note the tricky use of
 # conditional recursion to work around the fact that the GNU Make language does
@@ -286,7 +441,7 @@ __modules-closure = \
 	$(eval __closure_new := $(filter-out $(__closure_deps),$(__closure_val))) \
 	$(eval __closure_deps += $(__closure_new)) \
 	$(eval __closure_wq  := $(strip $(__closure_wq) $(__closure_new))) \
-	$(if $(__closure_wq),$(call __modules-closure)) \
+	$(if $(__closure_wq),$(call __modules-closure))
 
 ###############################################################################
 ## Get path of module main target file (in build or staging directory).
@@ -329,6 +484,15 @@ define generate-autoconf-file
 		$1 > $2;
 endef
 
+###############################################################################
+## Normalize a list of includes. It adds -I if needed.
+## $1 : list of includes
+###############################################################################
+normalize-c-includes = \
+	$(strip $(foreach __inc,$1, \
+		$(addprefix -I,$(patsubst -I%,%,$(__inc))) \
+	))
+
 ###############################################################################
 ## Commands for running gcc to generate a precompiled file.
 ###############################################################################
@@ -337,8 +501,9 @@ define transform-h-to-gch
 @mkdir -p $(dir $@)
 @echo "Precompile: $(PRIVATE_MODULE) <== $(call path-from-top,$<)"
 $(call check-pwd-is-top-dir)
-$(Q)$(CCACHE) $(CXX) \
-	$(TARGET_GLOBAL_C_INCLUDES) $(PRIVATE_C_INCLUDES) \
+$(Q)$(CCACHE) $(TARGET_CXX) \
+	$(TARGET_GLOBAL_C_INCLUDES) \
+	$(PRIVATE_C_INCLUDES) \
 	$(TARGET_GLOBAL_CFLAGS) $(TARGET_GLOBAL_CPPFLAGS) $(CXX_FLAGS_WARNINGS) \
 	$(PRIVATE_CFLAGS) $(PRIVATE_CPPFLAGS) \
 	$(TARGET_PCH_FLAGS) -MMD -MP -o $@ \
@@ -353,8 +518,9 @@ define transform-cpp-to-o
 @mkdir -p $(dir $@)
 @echo "$(DISPLAY_ARM_MODE)C++: $(PRIVATE_MODULE) <== $(call path-from-top,$<)"
 $(call check-pwd-is-top-dir)
-$(Q)$(CCACHE) $(CXX) \
-	$(TARGET_GLOBAL_C_INCLUDES) $(PRIVATE_C_INCLUDES) \
+$(Q)$(CCACHE) $(TARGET_CXX) \
+	$(TARGET_GLOBAL_C_INCLUDES) \
+	$(PRIVATE_C_INCLUDES) \
 	$(TARGET_GLOBAL_CFLAGS_$(PRIVATE_ARM_MODE)) \
 	$(TARGET_GLOBAL_CFLAGS) $(TARGET_GLOBAL_CPPFLAGS) $(CXX_FLAGS_WARNINGS) \
 	$(PRIVATE_CFLAGS) $(PRIVATE_CPPFLAGS) \
@@ -370,8 +536,9 @@ define transform-c-to-o
 @echo "$(DISPLAY_ARM_MODE)C: $(PRIVATE_MODULE) <== $(call path-from-top,$<)"
 $(call check-pwd-is-top-dir)
 @mkdir -p $(dir $@)
-$(Q)$(CCACHE) $(CC) \
-	$(TARGET_GLOBAL_C_INCLUDES) $(PRIVATE_C_INCLUDES) \
+$(Q)$(CCACHE) $(TARGET_CC) \
+	$(TARGET_GLOBAL_C_INCLUDES) \
+	$(PRIVATE_C_INCLUDES) \
 	$(TARGET_GLOBAL_CFLAGS_$(PRIVATE_ARM_MODE)) \
 	$(TARGET_GLOBAL_CFLAGS) $(CC_FLAGS_WARNINGS) \
 	$(PRIVATE_CFLAGS) \
@@ -387,8 +554,9 @@ define transform-s-to-o
 @ echo "ASM: $(PRIVATE_MODULE) <== $(call path-from-top,$<)"
 $(call check-pwd-is-top-dir)
 @mkdir -p $(dir $@)
-$(Q)$(CCACHE) $(CC) \
-	$(TARGET_GLOBAL_C_INCLUDES) $(PRIVATE_C_INCLUDES) \
+$(Q)$(CCACHE) $(TARGET_CC) \
+	$(TARGET_GLOBAL_C_INCLUDES) \
+	$(PRIVATE_C_INCLUDES) \
 	$(TARGET_GLOBAL_CFLAGS_$(PRIVATE_ARM_MODE)) \
 	$(TARGET_GLOBAL_CFLAGS) $(CC_FLAGS_WARNINGS) \
 	$(PRIVATE_CFLAGS) \
@@ -407,8 +575,8 @@ define transform-o-to-static-lib
 @echo "StaticLib: $(PRIVATE_MODULE) ==> $(call path-from-top,$@)"
 $(call check-pwd-is-top-dir)
 @rm -f $@
-$(Q)$(AR) $(TARGET_GLOBAL_ARFLAGS) $(PRIVATE_ARFLAGS) $@ $(PRIVATE_ALL_OBJECTS)
-$(Q)$(RANLIB) $@
+$(Q)$(TARGET_AR) $(TARGET_GLOBAL_ARFLAGS) $(PRIVATE_ARFLAGS) $@ $(PRIVATE_ALL_OBJECTS)
+$(Q)$(TARGET_RANLIB) $@
 endef
 
 ###############################################################################
@@ -419,7 +587,7 @@ define transform-o-to-shared-lib
 @mkdir -p $(dir $@)
 @echo "SharedLib: $(PRIVATE_MODULE) ==> $(call path-from-top,$@)"
 $(call check-pwd-is-top-dir)
-$(Q)$(CXX) \
+$(Q)$(TARGET_CXX) \
 	$(TARGET_GLOBAL_LDFLAGS_SHARED) \
 	-Wl,-Map -Wl,$(basename $@).map \
 	-shared \
@@ -446,7 +614,8 @@ define transform-o-to-executable
 @mkdir -p $(dir $@)
 @echo "Executable: $(PRIVATE_MODULE) ==> $(call path-from-top,$@)"
 $(call check-pwd-is-top-dir)
-$(Q)$(CXX) \
+@# TODO : Set LD ...
+$(Q)$(TARGET_CXX) \
 	$(TARGET_GLOBAL_LDFLAGS) \
 	-Wl,-Map -Wl,$(basename $@).map \
 	-Wl,-rpath-link=$(TARGET_OUT_STAGING)/lib \
@@ -464,13 +633,19 @@ $(Q)$(CXX) \
 	$(TARGET_GLOBAL_LDLIBS)
 endef
 
+#	--start-group \
+#	$(PRIVATE_ALL_STATIC_LIBRARIES) \
+#	$(PRIVATE_ALL_SHARED_LIBRARIES) \
+#	--end-group \
+#	-o $@ \
+
 ###############################################################################
 ## Commands for copying files.
 ###############################################################################
 
 # Copy a single file from one place to another, preserving permissions and
 # overwriting any existing file.
-define copy-file-to-target
+define do-copy-file
 @mkdir -p $(dir $@)
 $(Q)cp -fp $< $@
 endef
@@ -480,25 +655,8 @@ endef
 # $(2) : destination file
 define copy-one-file
 $(2): $(1)
-	@echo "Copy: $$(call path-from-top,$$@)"
-	$$(copy-file-to-target)
-endef
-
-###############################################################################
-## Default rules for a module.
-## $1 : module name.
-###############################################################################
-
-define def-rules
-
-.PHONY: $1
-$1: $(call module-get-build-filename,$1)
-
-.PHONY: clean-$1
-clean-$1:
-	@rm -f $(call module-get-build-filename,$1)
-	@rm -rf $(call module-get-build-dir,$1)
-
+	@echo "Copy: $$(call path-from-top,$$<) => $$(call path-from-top,$$@)"
+	$$(do-copy-file)
 endef
 
 ###############################################################################
@@ -512,7 +670,5 @@ local-get-path = $(call my-dir)
 local-get-build-dir = $(call module-get-build-dir,$(LOCAL_MODULE))
 
 # Register module
-local-add-module = \
-	$(call module-add,$(LOCAL_MODULE)) \
-	$(eval $(call def-rules,$(LOCAL_MODULE)))
+local-add-module = $(module-add)
 
diff --git a/core/executable.mk b/core/executable.mk
index 9430c5e..f69bf10 100644
--- a/core/executable.mk
+++ b/core/executable.mk
@@ -7,10 +7,13 @@
 ###############################################################################
 
 LOCAL_MODULE_CLASS := EXECUTABLE
+
+ifeq ("$(LOCAL_DESTDIR)","")
 LOCAL_DESTDIR := usr/bin
+endif
 
 ifeq ("$(LOCAL_MODULE_FILENAME)","")
 LOCAL_MODULE_FILENAME := $(LOCAL_MODULE)$(TARGET_EXE_SUFFIX)
 endif
 
-$(call module-add,$(LOCAL_MODULE))
+$(local-add-module)
diff --git a/core/main.mk b/core/main.mk
index 1e38300..8d47a67 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -30,44 +30,6 @@ ifeq ("$(V)","0")
   Q := @
 endif
 
-# Tools for host
-HOST_CC ?= gcc
-HOST_CXX ?= g++
-HOST_AR ?= ar
-HOST_LD ?= ld
-HOST_STRIP ?= strip
-
-# Tools for target
-ifneq ("$(CLANG)","1")
-	CC := $(CROSS)gcc
-	CXX := $(CROSS)g++
-else
-	CC := $(CROSS)clang
-	CXX := $(CROSS)clang++
-endif
-AR := $(CROSS)ar
-LD := $(CROSS)ld
-AS := $(CROSS)as
-NM := $(CROSS)nm
-STRIP := $(CROSS)strip
-RANLIB := $(CROSS)ranlib
-DLLTOOL := $(CROSS)dlltool
-
-
-# Target global variables
-TARGET_GLOBAL_C_INCLUDES ?=
-TARGET_GLOBAL_CFLAGS ?=
-TARGET_GLOBAL_CPPFLAGS ?=
-TARGET_GLOBAL_RCFLAGS ?=
-TARGET_GLOBAL_ARFLAGS ?= rcs
-TARGET_GLOBAL_LDFLAGS ?=
-TARGET_GLOBAL_LDFLAGS_SHARED ?=
-TARGET_GLOBAL_LDLIBS ?=
-TARGET_GLOBAL_LDLIBS_SHARED ?=
-TARGET_PCH_FLAGS ?=
-TARGET_DEFAULT_ARM_MODE ?= THUMB
-TARGET_GLOBAL_CFLAGS_ARM ?=
-TARGET_GLOBAL_CFLAGS_THUMB ?=
 
 ###############################################################################
 ## The folowing 2 macros can NOT be put in defs.mk as it will be included
@@ -107,7 +69,8 @@ CLEAR_VARS := $(BUILD_SYSTEM)/clearvars.mk
 BUILD_STATIC_LIBRARY := $(BUILD_SYSTEM)/static.mk
 BUILD_SHARED_LIBRARY := $(BUILD_SYSTEM)/shared.mk
 BUILD_EXECUTABLE := $(BUILD_SYSTEM)/executable.mk
-RULES := $(BUILD_SYSTEM)/rules.mk
+BUILD_PREBUILT := $(BUILD_SYSTEM)/prebuilt.mk
+BUILD_RULES := $(BUILD_SYSTEM)/rules.mk
 
 ###############################################################################
 ## Makefile scan and includes.
@@ -144,7 +107,7 @@ $(foreach __makefile,$(_tmpDirectory), \
     ) \
 )
 ifeq ("$(V)","1")
-	$(info makefiles="$(makefiles)")
+    $(info makefiles="$(makefiles)")
 endif
 # import all the makefiles
 include $(makefiles)
@@ -155,9 +118,16 @@ include $(makefiles)
 ###############################################################################
 
 # Recompute all dependencies between modules
-$(call modules-compute-dependencies)
+$(call modules-compute-depends)
 
-# Now, really build the modules, the second pass allows to deal with exported values
+# Check dependencies
+$(call modules-check-depends)
+
+# Check variables of modules
+$(call modules-check-variables)
+
+# Now, really generate rules for modules.
+# This second pass allows to deal with exported values.
 $(foreach __mod,$(__modules), \
     $(eval LOCAL_MODULE := $(__mod)) \
     $(eval include $(BUILD_SYSTEM)/module.mk) \
@@ -182,11 +152,21 @@ $(AUTOCONF_MERGE_FILE): $(__autoconf-list)
 # Main rules.
 ###############################################################################
 
+# All modules
+ALL_MODULES := \
+	$(foreach __mod,$(__modules),$(__mod))
+
+# All module to actually build
+ALL_BUILD_MODULES := \
+	$(foreach __mod,$(__modules), \
+		$(if $(call is-module-in-build-config,$(__mod)),$(__mod)))
+
+# TODO : Set ALL_BUILD_MODULES ==> find the end point module (SHARED/BINARY)
 .PHONY: all
-all: $(foreach __mod,$(__modules),$(__mod)) $(AUTOCONF_MERGE_FILE)
+all: $(ALL_MODULES) $(AUTOCONF_MERGE_FILE)
 
 .PHONY: clean
-clean: $(foreach __mod,$(__modules),clean-$(__mod))
+clean: $(foreach __mod,$(ALL_MODULES),clean-$(__mod))
 	@rm -f $(AUTOCONF_MERGE_FILE)
 
 # Dump the module database for debuging the build system
@@ -194,6 +174,15 @@ clean: $(foreach __mod,$(__modules),clean-$(__mod))
 dump:
 	$(call modules-dump-database)
 
+# Dump the module database for debuging the build system
+.PHONY: dump-depends
+dump-depends:
+	$(call modules-dump-database-depends)
+
+# Dummy target to check internal variables
+.PHONY: check
+check:
+
 ###############################################################################
 # Display configuration.
 ###############################################################################
@@ -204,6 +193,6 @@ $(info TARGET_ARCH: $(TARGET_ARCH))
 $(info TARGET_OUT_BUILD: $(TARGET_OUT_BUILD))
 $(info TARGET_OUT_STAGING: $(TARGET_OUT_STAGING))
 $(info TARGET_OUT_FINAL: $(TARGET_OUT_FINAL))
-$(info CC_PATH: $(CC_PATH))
-$(info CC_VERSION: $(CC_VERSION))
+$(info TARGET_CC_PATH: $(TARGET_CC_PATH))
+$(info TARGET_CC_VERSION: $(TARGET_CC_VERSION))
 $(info ----------------------------------------------------------------------)
diff --git a/core/module.mk b/core/module.mk
index d0d2b35..e26aa0d 100644
--- a/core/module.mk
+++ b/core/module.mk
@@ -9,19 +9,65 @@
 # Bring back all LOCAL_XXX variables defined by LOCAL_MODULE
 $(call module-restore-locals,$(LOCAL_MODULE))
 
+# Do we need to copy build module to staging dir
 copy_to_staging := 0
 
+# Full path to build module
+LOCAL_BUILD_MODULE := $(call module-get-build-filename,$(LOCAL_MODULE))
+
+# Full path to staging module
+LOCAL_STAGING_MODULE := $(call module-get-staging-filename,$(LOCAL_MODULE))
+
+# Assemble the list of targets to create PRIVATE_ variables for.
+LOCAL_TARGETS := $(LOCAL_BUILD_MODULE) clean-$(LOCAL_MODULE)
+
+# Add external libraries used by static libraries
+LOCAL_EXTERNAL_LIBRARIES += \
+	$(call module-get-depends,$(LOCAL_STATIC_LIBRARIES),EXTERNAL_LIBRARIES)
+LOCAL_EXTERNAL_LIBRARIES += \
+	$(call module-get-depends,$(LOCAL_WHOLE_STATIC_LIBRARIES),EXTERNAL_LIBRARIES)
+
+# List of external libraries that we need to depend on
+all_external_libraries := \
+	$(foreach lib,$(LOCAL_EXTERNAL_LIBRARIES), \
+		$(call module-get-build-filename,$(lib)))
+
+###############################################################################
+## Rule-specific variable definitions.
+###############################################################################
+
+$(LOCAL_TARGETS): PRIVATE_PATH := $(LOCAL_PATH)
+$(LOCAL_TARGETS): PRIVATE_MODULE := $(LOCAL_MODULE)
+$(LOCAL_TARGETS): PRIVATE_CLEAN_FILES := $(LOCAL_BUILD_MODULE)
+$(LOCAL_TARGETS): PRIVATE_CLEAN_DIRS :=
+
+###############################################################################
+## General rules.
+###############################################################################
+
+# Short hand to build module
+.PHONY: $(LOCAL_MODULE)
+$(LOCAL_MODULE): $(LOCAL_BUILD_MODULE)
+
+# Clean module (several other rules with commands can be added using ::)
+.PHONY: clean-$(LOCAL_MODULE)
+clean-$(LOCAL_MODULE)::
+	@echo "Clean: $(PRIVATE_MODULE)"
+	$(Q)$(if $(PRIVATE_CLEAN_FILES),rm -f $(PRIVATE_CLEAN_FILES))
+	$(Q)$(if $(PRIVATE_CLEAN_DIRS),rm -rf $(PRIVATE_CLEAN_DIRS))
+
 ###############################################################################
 ## Static library.
 ###############################################################################
 
 ifeq ("$(LOCAL_MODULE_CLASS)","STATIC_LIBRARY")
 
-include $(RULES)
+include $(BUILD_RULES)
 
 $(LOCAL_BUILD_MODULE): $(all_objects)
 	$(transform-o-to-static-lib)
 
+# TODO : the .a file does not arrive in the staging element ==> they micht stay in the obj folder
 copy_to_staging := 1
 
 endif
@@ -32,7 +78,7 @@ endif
 
 ifeq ("$(LOCAL_MODULE_CLASS)","SHARED_LIBRARY")
 
-include $(RULES)
+include $(BUILD_RULES)
 
 $(LOCAL_BUILD_MODULE): $(all_objects) $(all_libraries)
 	$(transform-o-to-shared-lib)
@@ -47,7 +93,7 @@ endif
 
 ifeq ("$(LOCAL_MODULE_CLASS)","EXECUTABLE")
 
-include $(RULES)
+include $(BUILD_RULES)
 
 $(LOCAL_BUILD_MODULE): $(all_objects) $(all_libraries)
 	$(transform-o-to-executable)
@@ -56,6 +102,44 @@ copy_to_staging := 1
 
 endif
 
+###############################################################################
+## Prebuilt.
+###############################################################################
+
+ifeq ("$(LOCAL_MODULE_CLASS)","PREBUILT")
+
+$(LOCAL_BUILD_MODULE):
+	@mkdir -p $(dir $@)
+	@touch $@
+
+endif
+
+###############################################################################
+## Files to copy.
+###############################################################################
+
+ifneq ("$(LOCAL_COPY_FILES)","")
+
+# List of all destination files
+all_copy_files :=
+
+# Generate a rule to copy all files
+$(foreach __pair,$(LOCAL_COPY_FILES), \
+	$(eval __pair2 := $(subst :,$(space),$(__pair))) \
+	$(eval __src := $(addprefix $(LOCAL_PATH)/,$(word 1,$(__pair2)))) \
+	$(eval __dst := $(addprefix $(TARGET_OUT_STAGING)/,$(word 2,$(__pair2)))) \
+	$(eval all_copy_files += $(__dst)) \
+	$(eval $(call copy-one-file,$(__src),$(__dst))) \
+)
+
+# Add files to be copied as pre-requisites
+$(LOCAL_BUILD_MODULE): $(all_copy_files)
+
+# Add rule to delete copied files during clean
+clean-$(LOCAL_MODULE):: PRIVATE_CLEAN_FILES += $(all_copy_files)
+
+endif
+
 ###############################################################################
 ## Copy to staging dir
 ###############################################################################
diff --git a/core/prebuilt.mk b/core/prebuilt.mk
new file mode 100644
index 0000000..56b1432
--- /dev/null
+++ b/core/prebuilt.mk
@@ -0,0 +1,15 @@
+###############################################################################
+## @file prebuilt.mk
+## @author Y.M. Morgan
+## @date 2012/08/08
+##
+## Register a prebuilt module.
+###############################################################################
+
+LOCAL_MODULE_CLASS := PREBUILT
+
+ifeq ("$(LOCAL_MODULE_FILENAME)","")
+LOCAL_MODULE_FILENAME := $(LOCAL_MODULE).done
+endif
+
+$(local-add-module)
diff --git a/core/rules.mk b/core/rules.mk
index 8a205cf..19f2de5 100644
--- a/core/rules.mk
+++ b/core/rules.mk
@@ -1,29 +1,14 @@
 ###############################################################################
-## @file rules.mk
+## @file binary-rules.mk
 ## @author Y.M. Morgan
 ## @date 2011/05/14
 ##
 ## Generate rules for building an executable or library.
 ###############################################################################
 
-# Make sure LOCAL_MODULE is defined and not empty
-LOCAL_MODULE := $(strip $(LOCAL_MODULE))
-ifeq ("$(LOCAL_MODULE)","")
-  $(error $(LOCAL_PATH): LOCAL_MODULE is not defined)
-endif
-
 # Intermediate/Build directory
 build_dir := $(TARGET_OUT_BUILD)/$(LOCAL_MODULE)
 
-# Full path to build module
-LOCAL_BUILD_MODULE := $(call module-get-build-filename,$(LOCAL_MODULE))
-
-# Full path to staging module
-LOCAL_STAGING_MODULE := $(call module-get-staging-filename,$(LOCAL_MODULE))
-
-# Assemble the list of targets to create PRIVATE_ variables for.
-LOCAL_TARGETS += $(LOCAL_BUILD_MODULE)
-
 # Prepend some directories in include list
 LOCAL_C_INCLUDES := $(build_dir) $(LOCAL_PATH) $(LOCAL_C_INCLUDES)
 
@@ -93,12 +78,12 @@ all_objects := \
 	$(cxx_objects) \
 	$(c_objects) \
 	$(s_objects) \
-	$(S_objects) \
+	$(S_objects)
 
 # Get all static libraries this module depends on
-LOCAL_STATIC_LIBRARIES := \
+LOCAL_STATIC_LIBRARIES += \
 	$(call module-get-depends,$(LOCAL_STATIC_LIBRARIES),STATIC_LIBRARIES)
-LOCAL_WHOLE_STATIC_LIBRARIES := \
+LOCAL_WHOLE_STATIC_LIBRARIES += \
 	$(call module-get-depends,$(LOCAL_WHOLE_STATIC_LIBRARIES),WHOLE_STATIC_LIBRARIES)
 
 # Also get shared libraries used by static libraries
@@ -117,7 +102,6 @@ all_static_libraries := \
 all_whole_static_libraries := \
 	$(foreach lib,$(LOCAL_WHOLE_STATIC_LIBRARIES), \
 		$(call module-get-staging-filename,$(lib)))
-
 all_external_libraries := \
 	$(foreach lib,$(LOCAL_EXTERNAL_LIBRARIES), \
 		$(TARGET_OUT_BUILD)/$(lib)/$(lib).done)
@@ -127,7 +111,7 @@ all_libraries := \
 	$(all_shared_libraries) \
 	$(all_static_libraries) \
 	$(all_whole_static_libraries) \
-	$(all_external_libraries) \
+	$(all_external_libraries)
 
 ###############################################################################
 ## Import of dependencies.
@@ -152,8 +136,6 @@ LOCAL_CPPFLAGS   := $(strip $(imported_CPPFLAGS) $(LOCAL_EXPORT_CPPFLAGS) $(LOCA
 # The imported/exported include directories are appended to their LOCAL_XXX value
 # (this allows the module to override them)
 LOCAL_C_INCLUDES := $(sort $(strip $(subst -I-I,-I,$(addprefix -I,$(LOCAL_C_INCLUDES) $(LOCAL_EXPORT_C_INCLUDES) $(imported_C_INCLUDES)))))
-#$(info LOCAL_C_INCLUDES=$(LOCAL_C_INCLUDES))
-#$(info -----)
 
 # Similarly, you want the imported/exported flags to appear _after_ the LOCAL_LDLIBS
 # due to the way Unix linkers work (depending libraries must appear before
@@ -180,6 +162,9 @@ all_prerequisites += $(all_autoconf)
 # User makefile is also a prerequisite
 all_prerequisites += $(LOCAL_PATH)/$(USER_MAKEFILE_NAME)
 
+# External libraries are also prerequisites
+all_prerequisites += $(all_external_libraries)
+
 # Notify that we build with dependencies
 LOCAL_CFLAGS += $(foreach __mod,$(all_depends), \
 	-DBUILD_$(call get-define,$(__mod)))
@@ -217,33 +202,20 @@ $(s_objects): $(build_dir)/%.o: $(LOCAL_PATH)/%.s
 endif
 
 # S files
-# There are dependency files for asm code...
+# There is dependency files for asm code...
 ifneq ("$(strip $(S_objects))","")
 $(S_objects): $(build_dir)/%.o: $(LOCAL_PATH)/%.S
 	$(transform-s-to-o)
 -include $(S_objects:%.o=%.d)
 endif
 
-# clean- targets
-cleantarget := clean-$(LOCAL_MODULE)
-$(cleantarget) : PRIVATE_MODULE := $(LOCAL_MODULE)
-$(cleantarget) : PRIVATE_CLEAN_FILES := \
-	$(LOCAL_BUILD_MODULE) \
-	$(LOCAL_STAGING_MODULE) \
-	$(build_dir)
-$(cleantarget)::
-	@echo "Clean: $(PRIVATE_MODULE)"
-	$(Q)rm -rf $(PRIVATE_CLEAN_FILES)
+# Additionnal clean
+clean-$(LOCAL_MODULE):: PRIVATE_CLEAN_FILES += $(LOCAL_STAGING_MODULE)
+clean-$(LOCAL_MODULE):: PRIVATE_CLEAN_DIRS += $(build_dir)
 
-## Provide a short-hand for building this module.
-.PHONY: $(LOCAL_MODULE)
+# Additional module dependencies
 $(LOCAL_MODULE): $(LOCAL_BUILD_MODULE) $(LOCAL_STAGING_MODULE)
 
-# Make sure external libraries are built first
-# Do NOT force rebuild at each check (order prerequisite)
-# TODO : check why order prerequisite
-#$(all_objects): | $(external_libraries)
-
 # Make sure all prerequisites files are generated first
 ifneq ("$(all_prerequisites)","")
 $(all_objects): $(all_prerequisites)
@@ -284,14 +256,10 @@ $(gch_file): $(LOCAL_PATH)/$(LOCAL_PRECOMPILED_FILE)
 	$(transform-h-to-gch)
 -include $(gch_file:%.gch=%.d)
 
-# Make sure external libraries are built first (order prerequisite)
-# TODO : check why order prerequisite
-#$(gch_file): | $(external_libraries)
-
 endif
 
 ###############################################################################
-# Rule-specific variable definitions.
+## Rule-specific variable definitions.
 ###############################################################################
 
 $(LOCAL_TARGETS): PRIVATE_PATH := $(LOCAL_PATH)
@@ -309,4 +277,3 @@ $(LOCAL_TARGETS): PRIVATE_ALL_WHOLE_STATIC_LIBRARIES := $(all_whole_static_libra
 $(LOCAL_TARGETS): PRIVATE_ALL_EXTERNAL_LIBRARIES := $(all_external_libraries)
 $(LOCAL_TARGETS): PRIVATE_ALL_OBJECTS := $(all_objects)
 
-
diff --git a/core/setup.mk b/core/setup.mk
index c925384..f6f0ec6 100644
--- a/core/setup.mk
+++ b/core/setup.mk
@@ -13,6 +13,52 @@ ifneq ("$(words $(shell pwd))","1")
 	$(error Top directory contains space characters)
 endif
 
+###############################################################################
+## Tools for target.
+###############################################################################
+
+ifneq ("$(CLANG)","1")
+	TARGET_CC := $(TARGET_CROSS)gcc
+	TARGET_CXX := $(TARGET_CROSS)g++
+else
+	TARGET_CC := $(TARGET_CROSS)clang
+	TARGET_CXX := $(TARGET_CROSS)clang++
+endif
+TARGET_AR := $(TARGET_CROSS)ar
+TARGET_LD := $(TARGET_CROSS)ld
+TARGET_NM := $(TARGET_CROSS)nm
+TARGET_STRIP := $(TARGET_CROSS)strip
+TARGET_STRIP := $(TARGET_CROSS)strip
+TARGET_RANLIB := $(TARGET_CROSS)ranlib
+TARGET_DLLTOOL := $(TARGET_CROSS)dlltool
+
+###############################################################################
+## Tools for host.
+###############################################################################
+HOST_GCC ?= gcc
+HOST_GXX ?= g++
+HOST_AR ?= ar
+HOST_LD ?= ld
+HOST_NM ?= nm
+HOST_STRIP ?= strip
+
+###############################################################################
+# Target global variables.
+###############################################################################
+TARGET_GLOBAL_C_INCLUDES ?=
+TARGET_GLOBAL_CFLAGS ?=
+TARGET_GLOBAL_CPPFLAGS ?=
+TARGET_GLOBAL_ARFLAGS ?= rcs
+TARGET_GLOBAL_LDFLAGS ?=
+TARGET_GLOBAL_LDFLAGS_SHARED ?=
+TARGET_GLOBAL_LDLIBS ?=
+TARGET_GLOBAL_LDLIBS_SHARED ?=
+TARGET_GLOBAL_CFLAGS_ARM ?=
+TARGET_GLOBAL_CFLAGS_THUMB ?=
+
+TARGET_PCH_FLAGS ?=
+TARGET_DEFAULT_ARM_MODE ?= THUMB
+
 ###############################################################################
 ## Host/Target OS.
 ###############################################################################
@@ -36,11 +82,9 @@ endif
 # Exe/dll suffix under mingw
 TARGET_STATIC_LIB_SUFFIX := .a
 ifeq ("$(TARGET_OS)","Windows")
-	DIR_SUFFIX := _mingw32
 	TARGET_EXE_SUFFIX := .exe
 	TARGET_SHARED_LIB_SUFFIX := .dll
 else
-	DIR_SUFFIX :=
 	TARGET_EXE_SUFFIX :=
 	TARGET_SHARED_LIB_SUFFIX := .so
 endif
@@ -105,7 +149,7 @@ endif
 
 # Architecture
 #ifndef TARGET_ARCH
-#  ifneq ("$(shell $(CC) -dumpmachine | grep 64)","")
+#  ifneq ("$(shell $(TARGET_CC) -dumpmachine | grep 64)","")
 #    TARGET_ARCH := AMD64
 #  else
 #    TARGET_ARCH := X86
@@ -120,29 +164,33 @@ endif
 #  TARGET_GLOBAL_CFLAGS += -m32
 #endif
 
+TARGET_GLOBAL_LDFLAGS += -L$(TARGET_OUT_STAGING)/lib
+TARGET_GLOBAL_LDFLAGS += -L$(TARGET_OUT_STAGING)/usr/lib
+TARGET_GLOBAL_LDFLAGS_SHARED += -L$(TARGET_OUT_STAGING)/lib
+TARGET_GLOBAL_LDFLAGS_SHARED += -L$(TARGET_OUT_STAGING)/usr/lib
 
 ###############################################################################
 ## Determine CC path and version. and check if installed ...
 ###############################################################################
 
-CC_PATH := $(shell which $(CC))
+TARGET_CC_PATH := $(shell which $(CC))
 
-ifeq ("$(CC_PATH)","")
+ifeq ("$(TARGET_CC_PATH)","")
     ifeq ("$(TARGET_OS)","Windows")
-        $(error Compilator does not exist : $(CC) ==> if not installed ... "apt-get install mingw32")
+        $(error Compilator does not exist : $(TARGET_CC) ==> if not installed ... "apt-get install mingw32")
     else ifeq ("$(TARGET_OS)","Android")
-        $(error Compilator does not exist : $(CC) ==> add and define the android NDK "http://developer.android.com/tools/sdk/ndk/index.html")
+        $(error Compilator does not exist : $(TARGET_CC) ==> add and define the android NDK "http://developer.android.com/tools/sdk/ndk/index.html")
     else
         ifneq ("$(CLANG)","1")
-            $(error Compilator does not exist : $(CC) ==> if not installed ... "apt-get install gcc g++")
+            $(error Compilator does not exist : $(TARGET_CC) ==> if not installed ... "apt-get install gcc g++")
         else
-            $(error Compilator does not exist : $(CC) ==> if not installed ... "apt-get install clang")
+            $(error Compilator does not exist : $(TARGET_CC) ==> if not installed ... "apt-get install clang")
         endif
     endif
 endif
 
 ifneq ("$(CLANG)","1")
-CC_VERSION := $(shell $(CC) --version | head -1 | sed "s/.*\([0-9]\.[0-9]\.[0-9]\).*/\1/")
+TARGET_CC_VERSION := $(shell $(TARGET_CC) --version | head -1 | sed "s/.*\([0-9]\.[0-9]\.[0-9]\).*/\1/")
 else
-CC_VERSION := $(shell $(CC) --version | head -1 | sed "s/.*\([0-9]\.[0-9]-[0-9]\).*/\1/")
+TARGET_CC_VERSION := $(shell $(TARGET_CC) --version | head -1 | sed "s/.*\([0-9]\.[0-9]-[0-9]\).*/\1/")
 endif
diff --git a/core/shared.mk b/core/shared.mk
index 355be9e..000b61c 100644
--- a/core/shared.mk
+++ b/core/shared.mk
@@ -7,10 +7,13 @@
 ###############################################################################
 
 LOCAL_MODULE_CLASS := SHARED_LIBRARY
+
+ifeq ("$(LOCAL_DESTDIR)","")
 LOCAL_DESTDIR := usr/lib
+endif
 
 ifeq ("$(LOCAL_MODULE_FILENAME)","")
 LOCAL_MODULE_FILENAME := $(LOCAL_MODULE)$(TARGET_SHARED_LIB_SUFFIX)
 endif
 
-$(call module-add,$(LOCAL_MODULE))
+$(local-add-module)
diff --git a/core/static.mk b/core/static.mk
index 9168a8d..0065b49 100644
--- a/core/static.mk
+++ b/core/static.mk
@@ -7,10 +7,13 @@
 ###############################################################################
 
 LOCAL_MODULE_CLASS := STATIC_LIBRARY
+
+ifeq ("$(LOCAL_DESTDIR)","")
 LOCAL_DESTDIR := usr/lib
+endif
 
 ifeq ("$(LOCAL_MODULE_FILENAME)","")
 LOCAL_MODULE_FILENAME := $(LOCAL_MODULE)$(TARGET_STATIC_LIB_SUFFIX)
 endif
 
-$(call module-add,$(LOCAL_MODULE))
+$(local-add-module)
diff --git a/core/warnings.mk b/core/warnings.mk
index ea05282..e4d6a3f 100644
--- a/core/warnings.mk
+++ b/core/warnings.mk
@@ -11,7 +11,7 @@ CC_FLAGS_WARNINGS :=
 CXX_FLAGS_WARNINGS :=
 
 # show option associated with warning (gcc >= 4.0.0)
-ifneq (0,$(shell expr $(CC_VERSION) \>= 4.0.0))
+ifneq (0,$(shell expr $(TARGET_CC_VERSION) \>= 4.0.0))
 	COMMON_FLAGS_WARNINGS += -fdiagnostics-show-option
 endif
 
@@ -41,11 +41,11 @@ endif
 
 ifneq ("$(CLANG)","1")
 	# gcc >= 4.5.0 (too many false positives with previous versions)
-	ifneq (0,$(shell expr $(CC_VERSION) \>= 4.5.0))
+	ifneq (0,$(shell expr $(TARGET_CC_VERSION) \>= 4.5.0))
 		COMMON_FLAGS_WARNINGS += -Wunreachable-code
 	endif
 	# gcc >= 4.5.2
-	ifneq (0,$(shell expr $(CC_VERSION) \>= 4.5.2))
+	ifneq (0,$(shell expr $(TARGET_CC_VERSION) \>= 4.5.2))
 		COMMON_FLAGS_WARNINGS += -Wlogical-op
 	endif
 endif
@@ -56,7 +56,7 @@ ifeq ("$(W)","1")
 	COMMON_FLAGS_WARNINGS += -Wswitch-enum
 	COMMON_FLAGS_WARNINGS += -Wcast-qual
 	# gcc >= 4.4.0
-	ifneq (0,$(shell expr $(CC_VERSION) \>= 4.4.0))
+	ifneq (0,$(shell expr $(TARGET_CC_VERSION) \>= 4.4.0))
 		COMMON_FLAGS_WARNINGS += -Wframe-larger-than=1024
 	endif
 endif