Change build output dir structure and filenames

Makefile.include

@@ -13,8 +13,6 @@ include $(CONTIKI)/Makefile.identify-target
 ### Include Makefile.tools to pull in targets that allow us to build tools dir
 include $(CONTIKI)/Makefile.tools
 
-CONTIKI_NG_TARGET_LIB = contiki-ng-$(TARGET).a
-
 ifeq ($(DEFINES),)
   -include Makefile.$(TARGET).defines
   ifneq ($(DEFINES),)
@@ -39,7 +37,12 @@ ifdef CI
   endif
 endif
 
-OBJECTDIR = obj_$(TARGET)
+BUILD_DIR = build
+BUILD_DIR_TARGET = $(BUILD_DIR)/$(TARGET)
+BUILD_DIR_BOARD = $(BUILD_DIR_TARGET)/$(BOARD)
+OBJECTDIR = $(BUILD_DIR_BOARD)/obj
+
+CONTIKI_NG_TARGET_LIB = $(BUILD_DIR_BOARD)/contiki-ng-$(TARGET).a
 
 LOWERCASE = -abcdefghijklmnopqrstuvwxyz/
 UPPERCASE = _ABCDEFGHIJKLMNOPQRSTUVWXYZ_
@@ -75,11 +78,6 @@ endef
 CONTIKI_OBJECTFILES = ${addprefix $(OBJECTDIR)/,${call oname, $(CONTIKI_SOURCEFILES)}}
 PROJECT_OBJECTFILES = ${addprefix $(OBJECTDIR)/,${call oname, $(PROJECT_SOURCEFILES)}}
 
-# Provide way to create $(OBJECTDIR) if it has been removed by make clean
-$(OBJECTDIR):
-	$(TRACE_MKDIR)
-	$(Q)mkdir $@
-
 uniq = $(if $1,$(firstword $1) $(call uniq,$(filter-out $(firstword $1),$1)))
 
 ### Include target makefile (TODO Unsafe?)
@@ -125,6 +123,11 @@ endif # $(BOARD) not empty
 
 PLATFORM_ACTION ?= build
 
+# Provide way to create $(OBJECTDIR) if it has been removed by make clean
+$(OBJECTDIR):
+	$(TRACE_MKDIR)
+	$(Q)mkdir -p $@
+
 ifneq ($(BOARD),)
   TARGET_BOARD_UPPERCASE := ${strip ${shell echo $(BOARD) | sed y!$(LOWERCASE)!$(UPPERCASE)!}}
   CFLAGS += -DCONTIKI_BOARD_$(TARGET_BOARD_UPPERCASE)=1
@@ -312,14 +315,13 @@ endef
 
 ### Harmonize filename of a .map file, if the platform's build system wants
 ### to create one
-CONTIKI_NG_PROJECT_MAP = $(addsuffix -$(TARGET).map, $(basename $@))
+CONTIKI_NG_PROJECT_MAP = $(BUILD_DIR_BOARD)/$(basename $(notdir $@)).map
 
 .PHONY: clean distclean usage help targets boards savetarget savedefines viewconf
 
 clean:
-	-$(Q)rm -f *.d *.e *.o $(CONTIKI_NG_TARGET_LIB) $(CLEAN)
-	-$(Q)rm -rf $(OBJECTDIR)
-	-$(Q)rm -f $(addsuffix -$(TARGET).map, $(CONTIKI_PROJECT))
+	-$(Q)rm -f *.d *.e *.o $(CLEAN)
+	-$(Q)rm -rf $(BUILD_DIR_TARGET)
 	-$(Q)rm -f $(addsuffix .$(TARGET), $(CONTIKI_PROJECT))
 	@echo Target $(TARGET) cleaned
 
@@ -328,6 +330,7 @@ distclean:
 		echo Running: $(MAKE) TARGET=$$TARG clean; \
 		$(MAKE) TARGET=$$TARG clean; \
 	done
+	rmdir $(BUILD_DIR)
 
 -include $(CONTIKI)/arch/platform/$(TARGET)/Makefile.customrules-$(TARGET)
 

arch/cpu/arm/Makefile.arm

@@ -51,27 +51,32 @@ endif
 ### CPU-dependent cleanup files
 CLEAN += *.elf *.bin *.lst *.hex *.i16hex
 
+OUT_HEX = $(BUILD_DIR_BOARD)/%.hex
+OUT_I16HEX = $(BUILD_DIR_BOARD)/%.i16hex
+OUT_BIN = $(BUILD_DIR_BOARD)/%.bin
+OUT_LST = $(BUILD_DIR_BOARD)/%.lst
+
 ### Don't treat the following files as intermediate
-.PRECIOUS: %.elf %.hex %.bin
+.PRECIOUS: $(OUT_ELF) $(OUT_HEX) $(OUT_BIN)
 
-%.i16hex: %.elf
+$(OUT_I16HEX): $(OUT_ELF)
 	$(TRACE_OBJCOPY)
 	$(Q)$(OBJCOPY) -O ihex $< $@
 
-%.hex: %.i16hex
+$(OUT_HEX): $(OUT_I16HEX)
 	$(TRACE_SREC_CAT)
 	$(Q)$(SREC_CAT) $< -intel -o $@ -intel
 
-%.bin: %.elf
+$(OUT_BIN): $(OUT_ELF)
 	$(TRACE_OBJCOPY)
 	$(Q)$(OBJCOPY) -O binary $(OBJCOPY_FLAGS) $< $@
 
-%.lst: %.elf
+$(OUT_LST): $(OUT_ELF)
 	$(TRACE_OBJDUMP)
 	$(Q)$(OBJDUMP) $(OBJDUMP_FLAGS) $< > $@
 
 ### We don't really need the .hex and .bin for the .$(TARGET) but let's make
 ### sure they get built
-%.$(TARGET): %.elf %.hex %.bin
+%.$(TARGET): $(OUT_ELF) $(OUT_HEX) $(OUT_BIN)
 	$(TRACE_CP)
 	$(Q)cp $< $@

arch/cpu/arm/cortex-m/Makefile.cortex-m

@@ -17,9 +17,11 @@ TARGET_LIBFLAGS := -Wl,--start-group $(TARGET_LIBFILES) -Wl,--end-group
 
 CUSTOM_RULE_LINK = 1
 
+OUT_ELF = $(BUILD_DIR_BOARD)/%.elf
+
 .SECONDEXPANSION:
 
-%.elf: $(CPU_STARTFILES) $$(CONTIKI_OBJECTFILES) %.o $(PROJECT_OBJECTFILES) $(PROJECT_LIBRARIES) $(LDSCRIPT) $(TARGET_LIBS)
+$(OUT_ELF): $(CPU_STARTFILES) $$(CONTIKI_OBJECTFILES) %.o $(PROJECT_OBJECTFILES) $(PROJECT_LIBRARIES) $(LDSCRIPT) $(TARGET_LIBS)
 	$(TRACE_LD)
 	$(Q)$(LD) $(LDFLAGS) ${filter-out $(LDSCRIPT) %.a,$^} ${filter %.a,$^} $(TARGET_LIBFLAGS) -o $@
 

arch/cpu/nrf52832/Makefile.nrf52832

@@ -172,11 +172,11 @@ vpath %.s $(ASM_PATHS)
 
 OBJECTS = $(C_OBJECTS) $(ASM_OBJECTS)
 
-CLEAN += nrf52832.a
+NRFLIB = $(BUILD_DIR_BOARD)/nrf52832.a
 
-TARGET_LIBS = nrf52832.a $(NRF52_SDK_ROOT)/components/iot/ble_6lowpan/lib/ble_6lowpan.a
+TARGET_LIBS = $(NRFLIB) $(NRF52_SDK_ROOT)/components/iot/ble_6lowpan/lib/ble_6lowpan.a
 
-nrf52832.a: $(OBJECTS)
+$(NRFLIB): $(OBJECTS)
 	$(TRACE_AR)
 	$(Q)$(AR) $(AROPTS) $@ $^