Checkpoint: application framework makefile done

Makefile

@@ -60,10 +60,13 @@ $(STAGED_FIRMWARES): $(IMAGE_DIR)/%.px4: $(BUILD_DIR)/%.build/firmware.px4
 $(BUILD_DIR)/%.build/firmware.px4: config   = $(patsubst $(BUILD_DIR)/%.build/firmware.px4,%,$@)
 $(BUILD_DIR)/%.build/firmware.px4: work_dir = $(BUILD_DIR)/$(config).build
 $(FIRMWARES): $(BUILD_DIR)/%.build/firmware.px4:
+	@echo %%%%
 	@echo %%%% Building $(config) in $(work_dir)
+	@echo %%%%
 	$(Q) mkdir -p $(work_dir)
 	$(Q) make -C $(work_dir) \
-		-f $(PX4_BASE)/makefiles/config_$(config).mk \
+		-f $(PX4_MK_DIR)/firmware.mk \
+		CONFIG=$(config) \
 		WORK_DIR=$(work_dir) \
 		firmware
 

makefiles/application.mk

@@ -0,0 +1,162 @@
+#
+# Framework makefile for PX4 applications
+#
+# This makefile is invoked by firmware.mk to build each of the applications
+# that will subsequently be linked into the firmware image.
+#
+# Applications are built as prelinked objects with a limited set of exported
+# symbols, as the global namespace is shared between all apps. Normally an 
+# application will just export one or more <command>_main functions.
+#
+
+#
+# Variables that can be set by the application's app.mk:
+#
+#
+# SRCS			(required)
+#	Lists the .c, cpp and .S files that should be compiled/assembled to
+#	produce the application.
+#
+# APP_NAME		(optional)
+# APP_ENTRYPOINT	(optional if APP_NAME is set)
+# APP_STACKSIZE		(optional if APP_NAME is set)
+# APP_PRIORITY		(optional if APP_NAME is set)
+#	Defines a single builtin command exported by the application.
+#	APP_NAME must be unique for any configuration, but need not be the 
+#	same as the app directory name.
+#	
+#	If APP_ENTRYPOINT is set, it names the function (which must be exported)
+#	that will be the entrypoint for the builtin command. It defaults to
+#	$(APP_NAME)_main.
+#
+#	If APP_STACKSIZE is set, it is the size in bytes of the stack to be
+#	allocated for the builtin command. If it is not set, it defaults
+#	to CONFIG_PTHREAD_STACK_DEFAULT.
+#
+#	If APP_PRIORITY is set, it is the thread priority for the builtin
+#	command. If it is not set, it defaults to SCHED_PRIORITY_DEFAULT.
+#
+# APP_COMMANDS		(optional)
+#	Defines builtin commands exported by the application. Each word in
+#	the list should be formatted as: 
+#		<command>.<priority>.<stacksize>.<entrypoint>
+#
+
+#
+# Variables visible to the application's app.mk:
+#
+# CONFIG
+# BOARD
+# APP_WORK_DIR
+# Anything set in setup.mk, board_$(BOARD).mk and the toolchain file.
+# Anything exported from config_$(CONFIG).mk
+#
+
+################################################################################
+# No user-serviceable parts below.
+################################################################################
+
+ifeq ($(APP_MK),)
+$(error No application makefile specified)
+endif
+
+#
+# Get path and tool config
+#
+include $(PX4_BASE)/makefiles/setup.mk
+
+#
+# Get the board/toolchain config
+#
+include $(PX4_MK_DIR)/board_$(BOARD).mk
+
+#
+# Get the application's config
+#
+include $(APP_MK)
+APP_SRC_DIR		:= $(dir $(APP_MK))
+
+#
+# Things that, if they change, might affect everything
+#
+GLOBAL_DEPS		+= $(MAKEFILE_LIST)
+
+################################################################################
+# Builtin command definitions
+################################################################################
+
+ifneq ($(APP_NAME),)
+APP_ENTRYPOINT		?= $(APP_NAME)_main
+APP_STACKSIZE		?= CONFIG_PTHREAD_STACK_DEFAULT
+APP_PRIORITY		?= SCHED_PRIORITY_DEFAULT
+APP_COMMANDS		+= $(APP_NAME).$(APP_PRIORITY).$(APP_STACKSIZE).$(APP_ENTRYPOINT)
+endif
+
+ifneq ($(APP_COMMANDS),)
+APP_COMMAND_FILES	:= $(addprefix $(WORK_DIR)/builtin_commands/COMMAND.,$(APP_COMMANDS))
+
+.PHONY: $(APP_COMMAND_FILES)
+$(APP_COMMAND_FILES): $(GLOBAL_DEPS)
+	@echo %% registering: $(word 2,$(subst ., ,$(notdir $(@))))
+	@mkdir -p $@
+	$(Q) touch $@
+endif
+
+################################################################################
+# Build rules
+################################################################################
+
+#
+# What we're going to build
+#
+app:			$(APP_OBJ) $(APP_COMMAND_FILES)
+
+#
+# Locate sources (allows relative source paths in app.mk)
+#
+define SRC_SEARCH
+	$(firstword $(wildcard $(APP_SRC_DIR)/$1) MISSING_$1)
+endef
+
+ABS_SRCS		:= $(foreach src,$(SRCS),$(call SRC_SEARCH,$(src)))
+MISSING_SRCS		:= $(subst MISSING_,,$(filter MISSING_%,$(ABS_SRCS)))
+ifneq ($(MISSING_SRCS),)
+$(error $(APP_MK): missing in SRCS: $(MISSING_SRCS))
+endif
+ifeq ($(ABS_SRCS),)
+$(error $(APP_MK): nothing to compile in SRCS)
+endif
+
+#
+# Object files we will generate from sources
+#
+OBJS			:= $(foreach src,$(ABS_SRCS),$(APP_WORK_DIR)/$(src).o)
+
+#
+# SRCS -> OBJS rules
+#
+
+$(OBJS):		$(GLOBAL_DEPS)
+
+$(filter %.c.o,$(OBJS)): $(APP_WORK_DIR)/%.c.o: %.c
+	$(call COMPILE,$<,$@)
+
+$(filter %.cpp.o,$(OBJS)): $(APP_WORK_DIR)/%.cpp.o: %.cpp $(GLOBAL_DEPS)
+	$(call COMPILEXX,$<,$@)
+
+$(filter %.S.o,$(OBJS)): $(APP_WORK_DIR)/%.S.o: %.S $(GLOBAL_DEPS)
+	$(call ASSEMBLE,$<,$@)
+
+#
+# Built product rules
+#
+
+$(APP_OBJ):		$(OBJS) $(GLOBAL_DEPS)
+	$(call PRELINK,$@,$(OBJS))
+
+#
+# Utility rules
+#
+
+clean:
+	$(Q) $(REMOVE) $(APP_PRELINK) $(OBJS)

makefiles/config_px4fmu_default.mk

@@ -2,13 +2,19 @@
 # Makefile for the px4fmu_default configuration
 #
 
-CONFIG		 = px4fmu_default
+#
-SRCS		 = $(PX4_BASE)/platforms/empty.c
+# Use the configuration's ROMFS.
+#
 ROMFS_ROOT	 = $(PX4_BASE)/ROMFS/$(CONFIG)
 
-# Commands from the NuttX export archive
+#
+# Add commands from the NuttX export archive.
 #
 # Each entry here is <command>.<priority>.<stacksize>.<entrypoint>
+#
 BUILTIN_COMMANDS = perf.SCHED_PRIORITY_DEFAULT.CONFIG_PTHREAD_STACK_DEFAULT.perf_main
 
-include $(PX4_MK_DIR)/firmware.mk
+#
+# Build the test app
+#
+APPS		 = test

makefiles/config_px4io_default.mk

@@ -2,7 +2,4 @@
 # Makefile for the px4io_default configuration
 #
 
-CONFIG		 = px4io_default
+# ... nothing here yet
-SRCS		 = $(PX4_BASE)/platforms/empty.c
-
-include $(PX4_MK_DIR)/firmware.mk

makefiles/firmware.mk

@@ -1,8 +1,5 @@
 #
-# Generic Makefile for PX4 firmware.
+# Generic Makefile for PX4 firmware images.
-#
-# Currently this assumes that we're just compiling SRCS
-# and then linking the whole thing together.
 #
 # Requires:
 #
@@ -12,6 +9,39 @@
 #
 # Optional:
 #
+# APPS
+#	Contains a list of application paths or path fragments used
+#	to find applications. The names listed here are searched in
+#	the following directories:
+#		<absolute path>
+#		$(APP_SEARCH_DIRS)
+#		WORK_DIR
+#		APP_SRC
+#		PX4_APP_SRC
+#
+#	Application directories are expected to contain an 'app.mk'
+#	file which provides build configuration for the app. See
+#	application.mk for more details.
+#
+# LIBS
+#	Contains a list of library paths or path fragments used
+#	to find libraries. The names listed here are searched in the
+#	following directories:
+#		<absolute path>
+#		$(LIB_SEARCH_DIRS)
+#		WORK_DIR
+#		LIB_SRC
+#		PX4_LIB_SRC
+#
+#	Library directories are expected to contain a 'lib.mk'
+#	file which provides build configuration for the library. See
+#	library.mk for more details.
+#
+# BUILTIN_COMMANDS
+#	Contains a list of built-in commands not explicitly provided
+#	by applications / libraries. Each entry in this list is formatted
+#	as <command>.<priority>.<stacksize>.<entrypoint>
+#
 # PX4_BASE:
 #	Points to a PX4 distribution. Normally determined based on the
 #	path to this file.
@@ -29,6 +59,14 @@
 #	containing the files under the directory and linked into the final
 #	image.
 #
+# APP_SEARCH_DIRS:
+#	Extra directories to search first for APPS before looking in the
+#	usual places.
+#
+# LIB_SEARCH_DIRS:
+#	Extra directories to search first for LIBS before looking in the
+#	usual places.
+#
 
 ################################################################################
 # Paths and configuration
@@ -41,17 +79,57 @@
 # If PX4_BASE wasn't set previously, work out what it should be
 # and set it here now.
 #
-export MK_DIR	?= $(dir $(lastword $(MAKEFILE_LIST)))
+MK_DIR	?= $(dir $(lastword $(MAKEFILE_LIST)))
 ifeq ($(PX4_BASE),)
 export PX4_BASE		:= $(abspath $(MK_DIR)/..)
 $(info %% set PX4_BASE to $(PX4_BASE))
 endif
 
+#
+# Set a default target so that included makefiles or errors here don't 
+# cause confusion.
+#
+# XXX We could do something cute here with $(DEFAULT_GOAL) if it's not one
+#     of the maintenance targets and set CONFIG based on it.
+#
+all:		firmware
+
 #
 # Get path and tool config
 #
 include $(MK_DIR)/setup.mk
 
+#
+# Locate the configuration file
+#
+ifeq ($(CONFIG),)
+$(error Missing configuration name or file (specify with CONFIG=<config>))
+endif
+CONFIG_FILE		:= $(firstword $(wildcard $(CONFIG)) $(wildcard $(PX4_MK_DIR)/config_$(CONFIG).mk))
+ifeq ($(CONFIG_FILE),)
+$(error Can't find a config file called $(CONFIG) or $(PX4_MK_DIR)/config_$(CONFIG).mk)
+endif
+export CONFIG
+include $(CONFIG_FILE)
+$(info %% CONFIG     $(CONFIG))
+
+#
+# Sanity-check the BOARD variable and then get the board config.
+# If BOARD was not set by the configuration, extract it automatically.
+#
+# The board config in turn will fetch the toolchain configuration.
+#
+ifeq ($(BOARD),)
+BOARD			:= $(firstword $(subst _, ,$(CONFIG)))
+endif
+BOARD_FILE		:= $(wildcard $(PX4_MK_DIR)/board_$(BOARD).mk)
+ifeq ($(BOARD_FILE),)
+$(error Config $(CONFIG) references board $(BOARD), but no board definition file found)
+endif
+export BOARD
+include $(BOARD_FILE)
+$(info %% BOARD      $(BOARD))
+
 #
 # If WORK_DIR is not set, create a 'build' directory next to the
 # parent Makefile.
@@ -62,63 +140,66 @@ export WORK_DIR		:= $(dir $(PARENT_MAKEFILE))/build
 endif
 $(info %% WORK_DIR   $(WORK_DIR))
 
-#
-# Sanity-check the BOARD variable and then get the board config.
-# If BOARD is not set, but CONFIG is, use that.
-#
-# The board config in turn will fetch the toolchain configuration.
-#
-ifeq ($(BOARD),)
-ifeq ($(CONFIG),)
-$(error At least one of the BOARD or CONFIG variables must be set before including firmware.mk)
-endif
-BOARD		:= $(firstword $(subst _, ,$(CONFIG)))
-endif
-include $(PX4_MK_DIR)/board_$(BOARD).mk
-
 #
 # Things that, if they change, might affect everything
 #
 GLOBAL_DEPS		+= $(MAKEFILE_LIST)
 
+################################################################################
+# Applications
+################################################################################
+
+# where to look for applications
+APP_SEARCH_DIRS		 += $(WORK_DIR) $(APP_SRC) $(PX4_APP_SRC)
+
+# sort and unique the apps list
+APPS			:= $(sort $(APPS))
+
+# locate the first instance of an app by full path or by looking on the
+# application search path
+define APP_SEARCH
+	$(firstword $(wildcard $(1)/app.mk) \
+		$(foreach search_dir,$(APP_SEARCH_DIRS),$(wildcard $(search_dir)/$(1)/app.mk)) \
+		MISSING_$1)
+endef
+
+APP_MKFILES		:= $(foreach app,$(APPS),$(call APP_SEARCH,$(app)))
+MISSING_APPS		:= $(subst MISSING_,,$(filter MISSING_%,$(APP_MKFILES)))
+ifneq ($(MISSING_APPS),)
+$(error Can't find application(s): $(MISSING_APPS))
+endif
+
+APP_OBJS		:= $(foreach path,$(dir $(APP_MKFILES)),$(WORK_DIR)/$(path)/app.pre.o)
+
+$(APP_OBJS):		relpath = $(patsubst $(WORK_DIR)/%,%,$@)
+$(APP_OBJS):		mkfile = $(patsubst %/app.pre.o,%/app.mk,$(relpath))
+$(APP_OBJS):		$(GLOBAL_DEPS) $(NUTTX_CONFIG_HEADER)
+	@echo %%
+	@echo %% Building app in $(relpath) using $(mkfile)
+	@echo %%
+	$(Q) make -f $(PX4_MK_DIR)/application.mk \
+		APP_WORK_DIR=$(dir $@) \
+		APP_OBJ=$@ \
+		APP_MK=$(mkfile) \
+		app
+
+APP_CLEANS		:= $(foreach path,$(dir $(APP_MKFILES)),$(WORK_DIR)/$(path)/clean)
+
+.PHONY: $(APP_CLEANS)
+$(APP_CLEANS):		relpath = $(patsubst $(WORK_DIR)/%,%,$@)
+$(APP_CLEANS):		mkfile = $(patsubst %/clean,%/app.mk,$(relpath))
+$(APP_CLEANS):
+	@echo %% cleaning using $(mkfile)
+	$(Q) make -f $(PX4_MK_DIR)/application.mk \
+	APP_WORK_DIR=$(dir $@) \
+	APP_MK=$(mkfile) \
+	clean
+
 ################################################################################
 # NuttX libraries and paths
 ################################################################################
 
-#
+include $(PX4_MK_DIR)/nuttx.mk
-# Check that the NuttX archive for the selected board is available.
-#
-NUTTX_ARCHIVE		:= $(wildcard $(ARCHIVE_DIR)/$(BOARD).export)
-ifeq ($(NUTTX_ARCHIVE),)
-$(error The NuttX export archive for $(BOARD) is missing from $(ARCHIVE_DIR) - try 'make archives' in $(PX4_BASE))
-endif
-
-#
-# The NuttX config header should always be present in the NuttX archive, and
-# if it changes, everything should be rebuilt. So, use it as the trigger to
-# unpack the NuttX archive.
-#
-NUTTX_EXPORT_DIR	 = $(WORK_DIR)/nuttx-export
-NUTTX_CONFIG_HEADER	 = $(NUTTX_EXPORT_DIR)/include/nuttx/config.h
-GLOBAL_DEPS		+= $(NUTTX_CONFIG_HEADER)
-
-#
-# Use the linker script from the NuttX export
-#
-LDSCRIPT		 = $(NUTTX_EXPORT_DIR)/build/ld.script
-
-#
-# Add directories from the NuttX export to the relevant search paths
-#
-INCLUDE_DIRS		+= $(NUTTX_EXPORT_DIR)/include
-LIB_DIRS		+= $(NUTTX_EXPORT_DIR)/libs
-LIBS			+= -lapps -lnuttx
-LINK_DEPS		+= $(wildcard $(addsuffix /*.a,$(LIB_DIRS)))
-
-$(NUTTX_CONFIG_HEADER):	$(NUTTX_ARCHIVE)
-	@echo %% Unpacking $(NUTTX_ARCHIVE)
-	$(Q) unzip -q -o -d $(WORK_DIR) $(NUTTX_ARCHIVE)
-	$(Q) touch $@
 
 ################################################################################
 # ROMFS generation
@@ -149,7 +230,7 @@ $(ROMFS_CSRC): $(ROMFS_IMG)
 	@echo %% generating $@
 	$(Q) (cd $(dir $<) && xxd -i $(notdir $<)) > $@
 
-$(ROMFS_IMG): $(ROMFS_DEPS)
+$(ROMFS_IMG): $(ROMFS_DEPS) $(GLOBAL_DEPS)
 	@echo %% generating $@
 	$(Q) $(GENROMFS) -f $@ -d $(ROMFS_ROOT) -V "NSHInitVol"
 
@@ -163,8 +244,6 @@ endif
 # Note that we can't just put builtin_commands.c in SRCS, as it's depended on by the
 # NuttX export library. Instead, we have to treat it like a library.
 #
-# XXX need to fix stack size numbers here so that apps can set them.
-#
 # Builtin commands can be generated by the configuration, in which case they
 # must refer to commands that already exist, or indirectly generated by applications
 # when they are built.
@@ -181,7 +260,7 @@ endif
 BUILTIN_CSRC		 = $(WORK_DIR)/builtin_commands.c
 
 # add command definitions from apps
-BUILTIN_COMMANDS	+= $(subst COMMAND.,,$(notdir $(wildcard $(WORK_DIR)/builtin_commands/APP.*)))
+BUILTIN_COMMANDS	+= $(subst COMMAND.,,$(notdir $(wildcard $(WORK_DIR)/builtin_commands/COMMAND.*)))
 
 # (BUILTIN_PROTO,<cmdspec>,<outputfile>)
 define BUILTIN_PROTO
@@ -193,7 +272,7 @@ define BUILTIN_DEF
 	echo '    {"$(word 1,$1)", $(word 2,$1), $(word 3,$1), $(word 4,$1)},' >> $2;
 endef
 
-$(BUILTIN_CSRC):	$(MAKEFILE_LIST)
+$(BUILTIN_CSRC):	$(GLOBAL_DEPS)
 	@echo %% generating $@
 	$(Q) echo '/* builtin command list - automatically generated, do not edit */' > $@
 	$(Q) echo '#include <nuttx/config.h>' >> $@
@@ -209,7 +288,7 @@ BUILTIN_OBJ		 = $(BUILTIN_CSRC:.c=.o)
 LIBS			+= $(BUILTIN_OBJ)
 LINK_DEPS		+= $(BUILTIN_OBJ)
 
-$(BUILTIN_OBJ): $(BUILTIN_CSRC) $(GLOBAL_DEPS)
+$(BUILTIN_OBJ): $(BUILTIN_CSRC)
 	$(Q) $(call COMPILE,$<,$@)
 
 ################################################################################
@@ -239,7 +318,7 @@ PRODUCT_BUNDLE		 = $(WORK_DIR)/firmware.px4
 PRODUCT_BIN		 = $(WORK_DIR)/firmware.bin
 PRODUCT_SYM		 = $(WORK_DIR)/firmware.sym
 
-.PHONY:			all
+.PHONY:			firmware
 firmware:		$(PRODUCT_BUNDLE)
 
 #
@@ -254,15 +333,12 @@ OBJS			:= $(foreach src,$(SRCS),$(WORK_DIR)/$(src).o)
 $(OBJS):		$(GLOBAL_DEPS)
 
 $(filter %.c.o,$(OBJS)): $(WORK_DIR)/%.c.o: %.c
-	@mkdir -p $(dir $@)
 	$(call COMPILE,$<,$@)
 
 $(filter %.cpp.o,$(OBJS)): $(WORK_DIR)/%.cpp.o: %.cpp $(GLOBAL_DEPS)
-	@mkdir -p $(dir $@)
 	$(call COMPILEXX,$<,$@)
 
 $(filter %.S.o,$(OBJS)): $(WORK_DIR)/%.S.o: %.S $(GLOBAL_DEPS)
-	@mkdir -p $(dir $@)
 	$(call ASSEMBLE,$<,$@)
 
 #
@@ -278,21 +354,23 @@ $(PRODUCT_BUNDLE):	$(PRODUCT_BIN)
 $(PRODUCT_BIN):		$(PRODUCT_SYM)
 	$(call SYM_TO_BIN,$<,$@)
 
-$(PRODUCT_SYM):		$(OBJS) $(GLOBAL_DEPS) $(LINK_DEPS)
+$(PRODUCT_SYM):		$(OBJS) $(APP_OBJS) $(GLOBAL_DEPS) $(LINK_DEPS) $(APP_MKFILES)
-	$(call LINK,$@,$(OBJS))
+	$(call LINK,$@,$(OBJS) $(APP_OBJS))
 
 #
 # Utility rules
 #
 
+.PHONY: upload
 upload:	$(PRODUCT_BUNDLE) $(PRODUCT_BIN)
-	$(Q) make -f $(PX4_MK_INCLUDE)/upload.mk \
+	$(Q) make -f $(PX4_MK_DIR)/upload.mk \
 		METHOD=serial \
 		PRODUCT=$(PRODUCT) \
 		BUNDLE=$(PRODUCT_BUNDLE) \
 		BIN=$(PRODUCT_BIN)
 
-clean:
+.PHONY: clean
+clean:			$(APP_CLEANS)
 	@echo %% cleaning
 	$(Q) $(REMOVE) $(PRODUCT_BUNDLE) $(PRODUCT_BIN) $(PRODUCT_SYM)
 	$(Q) $(REMOVE) $(OBJS) $(DEP_INCLUDES)

makefiles/nuttx.mk

@@ -0,0 +1,40 @@
+#
+# Rules and definitions related to handling the NuttX export archives when
+# building firmware.
+#
+
+#
+# Check that the NuttX archive for the selected board is available.
+#
+NUTTX_ARCHIVE		:= $(wildcard $(ARCHIVE_DIR)/$(BOARD).export)
+ifeq ($(NUTTX_ARCHIVE),)
+$(error The NuttX export archive for $(BOARD) is missing from $(ARCHIVE_DIR) - try 'make archives' in $(PX4_BASE))
+endif
+
+#
+# The NuttX config header should always be present in the NuttX archive, and
+# if it changes, everything should be rebuilt. So, use it as the trigger to
+# unpack the NuttX archive.
+#
+NUTTX_EXPORT_DIR	 = $(WORK_DIR)/nuttx-export
+NUTTX_CONFIG_HEADER	 = $(NUTTX_EXPORT_DIR)/include/nuttx/config.h
+GLOBAL_DEPS		+= $(NUTTX_CONFIG_HEADER)
+
+#
+# Use the linker script from the NuttX export
+#
+LDSCRIPT		 = $(NUTTX_EXPORT_DIR)/build/ld.script
+
+#
+# Add directories from the NuttX export to the relevant search paths
+#
+INCLUDE_DIRS		+= $(NUTTX_EXPORT_DIR)/include
+LIB_DIRS		+= $(NUTTX_EXPORT_DIR)/libs
+LIBS			+= -lapps -lnuttx
+LINK_DEPS		+= $(NUTTX_EXPORT_DIR)/libs/libapps.a \
+			   $(NUTTX_EXPORT_DIR)/libs/libnuttx.a
+
+$(NUTTX_CONFIG_HEADER):	$(NUTTX_ARCHIVE)
+	@echo %% Unpacking $(NUTTX_ARCHIVE)
+	$(Q) unzip -q -o -d $(WORK_DIR) $(NUTTX_ARCHIVE)
+	$(Q) touch $@

makefiles/setup.mk

@@ -39,5 +39,5 @@ endif
 #
 # Makefile debugging.
 #
-Q			:= $(if $(V),,@)
+export Q		:= $(if $(V),,@)
 

makefiles/toolchain_gnu-arm-eabi.mk

@@ -2,7 +2,7 @@
 # Definitions for a generic GNU ARM-EABI toolchain
 #
 
-$(info %% Toolchain: gnu-arm-eabi)
+$(info %% TOOLCHAIN  gnu-arm-eabi)
 
 CROSSDEV		 = arm-none-eabi-
 
@@ -131,16 +131,11 @@ LINK_DEPS		+= $(LDSCRIPT)
 # files to include to get automated dependencies
 DEP_INCLUDES		 = $(subst .o,.d,$(OBJS))
 
-ifeq ($(V),)
-Q			 = @
-else
-Q			 =
-endif
-
 # compile C source $1 to object $2
 # as a side-effect, generate a dependency file
 define COMPILE
 	@echo "CC: $1"
+	@mkdir -p $(dir $2)
 	$(Q) $(CC) -MD -c $(CFLAGS) $(abspath $1) -o $2
 endef
 
@@ -148,35 +143,41 @@ endef
 # as a side-effect, generate a dependency file
 define COMPILEXX
 	@echo "CXX: $1"
+	@mkdir -p $(dir $2)
 	$(Q) $(CXX) -MD -c $(CXXFLAGS) $(abspath $1) -o $2
 endef
 
 # assemble $1 into $2
 define ASSEMBLE
 	@echo "AS: $1"
+	@mkdir -p $(dir $2)
 	$(Q) $(CC) -c $(AFLAGS) $(abspath $1) -o $2
 endef
 
 # produce partially-linked $1 from files in $2
 define PRELINK
 	@echo "PRELINK: $1"
+	@mkdir -p $(dir $1)
 	$(Q) $(LD) -Ur -o $1 $2 && $(OBJCOPY) --localize-hidden $1
 endef
 
 # update the archive $1 with the files in $2
 define ARCHIVE
 	@echo "AR: $2"
+	@mkdir -p $(dir $1)
 	$(Q) $(AR) $1 $2
 endef
 
 # Link the objects in $2 into the binary $1
 define LINK
 	@echo "LINK: $1"
-	$(Q) $(LD) $(LDFLAGS) -o $1 --start-group $(LIBS) $(EXTRA_LIBS) $(LIBGCC) --end-group
+	@mkdir -p $(dir $1)
+	$(Q) $(LD) $(LDFLAGS) -o $1 $2 --start-group $(LIBS) $(EXTRA_LIBS) $(LIBGCC) --end-group
 endef
 
 # convert $1 from a linked object to a raw binary
 define SYM_TO_BIN
 	@echo "BIN: $2"
+	@mkdir -p $(dir $2)
 	$(Q) $(OBJCOPY) -O binary $1 $2
 endef

src/apps/test/app.mk

@@ -0,0 +1,4 @@
+
+APP_NAME	 = test
+SRCS		 = foo.c
+