From 30c2e473eea6dbd0f0ebb2a4ffd94328b3493415 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Tue, 27 Jun 2017 15:33:31 +0200
Subject: [PATCH] better handle libopencm3 dependency

---
 Makefile | 43 +++++++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/Makefile b/Makefile
index 14d4e31..5348451 100644
--- a/Makefile
+++ b/Makefile
@@ -30,6 +30,14 @@ FIRMWARE = $(APPLICATION) $(BOOTLOADER)
 # supported are: SYSTEM_BOARD, MAPLE_MINI, BLUE_PILL, CORE_BOARD
 BOARD = SYSTEM_BOARD
 
+# opencm3 libraries
+OPENCM3_DIR := libopencm3
+OPENCM3_INC = $(OPENCM3_DIR)/include
+OPENCM3_LIB = $(OPENCM3_DIR)/lib
+
+# library for the STM32F1 (provided by opencm3)
+STM32F1_LIB = opencm3_stm32f1
+
 # source files (this will be populated using includes based DEPENDENCIES)
 CSRC = global.c
 # headers corresponding to source files
@@ -56,13 +64,6 @@ GDB := $(ELLCC)bin/ecc-gdb
 # ecc-gdb (0.13.3) is buggy (crash on kill, can't load elf)
 GDB := arm-none-eabi-gdb
 
-# opencm3 libraries
-OPENCM3_DIR := libopencm3
-OPENCM3_INC = $(OPENCM3_DIR)/include
-OPENCM3_LIB = $(OPENCM3_DIR)/lib
-# library for the STM32F1 (provided by opencm3)
-STM32F1_LIB = opencm3_stm32f1
-
 # device micro-controller and board
 DEFS += -DSTM32F1 -D$(BOARD)
 
@@ -107,8 +108,6 @@ LDFLAGS += -nostdlib -nostdinc
 LDFLAGS += --library-path $(ELLCC)libecc/lib/cortex-m3-linux/
 # opencm3 libraries
 LDFLAGS += --library-path $(OPENCM3_LIB)
-# linker script with definitions for micro-controller
-#LDFLAGS += --script $(LDSCRIPT)
 # used libraries (gcc provides the ARM ABI, not sure how to replace with compiler-rt)
 LDLIBS += --library $(STM32F1_LIB) --library c --library m --library gcc
 
@@ -129,7 +128,7 @@ BMP_PORT ?= /dev/ttyACM0
 endif
 
 # compile target rules
-all: $(OPENCM3_LIB)/lib$(STM32F1_LIB).a elf hex bin
+all: elf hex bin
 
 elf: $(patsubst %,%.elf,$(FIRMWARE))
 bin: $(patsubst %,%.bin,$(FIRMWARE))
@@ -149,12 +148,12 @@ hex: $(patsubst %,%.hex,$(FIRMWARE))
 	$(Q)$(LD) $(LDFLAGS) --script $(*).ld $(<) $(OBJ) $(LDLIBS) -o $(@)
 	$(Q)size $(@)
 
-%.o: %.c $(CHDR)
+%.o: %.c $(CHDR) $(OPENCM3_LIB)/lib$(STM32F1_LIB).a
 	$(info compiling $(@))
 	$(Q)$(CC) $(CFLAGS) $(ARCH_FLAGS) -o $(@) -c $(<)
 
-# generate dependencies
-%.d: %.c
+# generate dependencies (requires libopencm3 to be built to generate all libraries)
+%.d: %.c $(OPENCM3_LIB)/lib$(STM32F1_LIB).a
 	@# check which libraries are used
 	$(Q)$(CC) $(CFLAGS) $(ARCH_FLAGS) -MM -MF $(@) -o /dev/null -c $(<)
 
@@ -162,6 +161,17 @@ hex: $(patsubst %,%.hex,$(FIRMWARE))
 %.inc: %.d
 	$(Q)grep -o -e " lib\/[^ ]*\.h" $(<) | sed -e 's|\(.*\)\.h$$|CSRC +=\1.c\n-include\1.inc|g' -e 's|.*${*}.*||g' > $(@)
 
+# get libopencm3
+$(OPENCM3_DIR)/Makefile:
+	$(info checking out libopencm3 submodule)
+	$(Q)git submodule init
+	$(Q)git submodule update
+
+# compile libopencm3
+$(OPENCM3_LIB)/lib$(STM32F1_LIB).a: $(OPENCM3_DIR)/Makefile
+	$(info compiling libopencm3 submodule)
+	$(Q)CFLAGS=-fno-short-enums $(MAKE) --directory $(OPENCM3_DIR)
+
 # doxygen documentation
 doc: Doxyfile README.md $(patsubst %,%.c,$(FIRMWARE)) $(CSRC) $(CHDR)
 	$(Q)doxygen $(<)
@@ -169,13 +179,6 @@ doc: Doxyfile README.md $(patsubst %,%.c,$(FIRMWARE)) $(CSRC) $(CHDR)
 clean:
 	$(Q)$(RM) $(BOOTLOADER).elf $(BOOTLOADER).bin $(BOOTLOADER).hex $(APPLICATION).elf $(APPLICATION).bin $(APPLICATION).hex $(OBJ) $(DEPENDENCIES) *.inc lib/*.inc
 
-# make libopencm3 if library for STM32F1 is not yet existing
-$(OPENCM3_LIB)/lib$(STM32F1_LIB).a:
-	$(info compiling libopencm3 library)
-	git submodule init
-	git submodule update
-	$(Q)$(MAKE) CFLAGS=-fno-short-enums -C $(OPENCM3_DIR)
-
 # flash application using DFU
 flash: $(APPLICATION).bin
 	$(Q)dfu-util -d c440:0d00 -D $(<)