From 4342eb802b047c80cbeadd7c728777c481c951e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Mon, 18 Jan 2016 15:48:21 +0100
Subject: [PATCH] add assembly support and use optiboot (over default arduino
 boot which does not support watchdog)

---
 Makefile | 46 +++++++++++++++++++++++++++-------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/Makefile b/Makefile
index a84e246..3b9ae33 100644
--- a/Makefile
+++ b/Makefile
@@ -12,9 +12,9 @@ F_CPU = 16000000UL
 PROGRAMMER = arduino
 PORT = /dev/ttyUSB0
 # to flash
-# use the aduino bootlaoder, with a baudrate of 57600
-# reset the device to start bootlaoder
-FLASHER = avrdude -p $(DEVICE) -c $(PROGRAMMER) -P $(PORT) -b 57600 -D
+# use the aduino bootloader, with a baudrate of 57600
+# reset the device to start (optiboot) bootloader
+FLASHER = avrdude -p $(DEVICE) -c $(PROGRAMMER) -P $(PORT) -b 115200 -D
 
 # compiler executables
 CC = avr-gcc
@@ -24,26 +24,29 @@ SIZE = avr-size
 
 # library directories, compiler, and linker flags
 LIBS = lib
-CFLAGS = -g -Wall -Werror -O3 -std=c99
+CFLAGS = -g -Wall -Werror -Os -mcall-prologues -std=c99
 CFLAGS += -I. $(patsubst %,-I%,$(LIBS))
 CFLAGS += -mmcu=$(DEVICE) -DF_CPU=$(F_CPU)
+AFLAGS = -Wall -Werror -x assembler-with-cpp
+AFLAGS += -I. $(patsubst %,-I%,$(LIBS))
+AFLAGS += -mmcu=$(DEVICE)
 LDFLAGS = -Wl,-Map=$(TARGET).map,--cref
 LDFLAGS += -I. $(patsubst %,-I%,$(LIBS))
 LDFLAGS += -mmcu=$(DEVICE)
 # floating point printf version (requires -lm below)
-#LDFLAGS += -Wl,-u,vfprintf -lprintf_flt
+LDFLAGS += -Wl,-u,vfprintf -lprintf_flt
 # math library
-#LDFLAGS += -lm
+LDFLAGS += -lm
 
 # source files to compile
-SRC = $(wildcard *.c)
-SRC += $(foreach LIB,$(LIBS),$(wildcard $(LIB)/*.c))
+CSRC = $(wildcard *.c) $(foreach LIB,$(LIBS),$(wildcard $(LIB)/*.c))
+ASRC = $(wildcard *.S) $(foreach LIB,$(LIBS),$(wildcard $(LIB)/*.S))
 # header files
 HEADER = $(SRC:.c=.h)
 # object files
-OBJ = $(SRC:.c=.o)
-# listing files.
-LST = $(SRC:.c=.lst)
+OBJ = $(patsubst %.c,%.o,$(CSRC)) $(patsubst %.S,%.o,$(ASRC))
+# listing files
+LST = $(patsubst %.c,%.lst,$(CSRC)) $(patsubst %.S,%.lst,$(ASRC))
 
 all: compile flash
 	$(info EEPROM has to be programmed separately)
@@ -56,21 +59,22 @@ debug: map lst all
 # after reset the bootloader is start
 # the bootloader can be used to reflash the device
 reset:
-	stty 57600 raw ignbrk hup < $(PORT)
+	stty 115200 raw ignbrk hup < $(PORT)
 
 # flash the device using the internal bootloader
 flash: $(TARGET).hex reset
 	$(FLASHER) -U flash:w:$<:i
 
-# write EEPROM on the device
+# write EEPROM on the device (optiboot has EEPROM capabilities disabled by default)
 eeprom: $(TARGET)_eeprom.hex reset
 	$(FLASHER) -U eeprom:w:$<:i
 
-# write bootloader and fuses
-bootloader:
-	wget https://arduino.googlecode.com/svn/trunk/hardware/arduino/bootloaders/atmega/ATmegaBOOT_168_atmega328.hex
-	avrdude -p $(DEVICE) -c usbtiny	-U lfuse:w:0xff:m -U hfuse:w:0xda:m -U efuse:w:0x05:m -U flash:w:ATmegaBOOT_168_atmega328.hex:i
-	rm ATmegaBOOT_168_atmega328.hex
+# write bootloader (optiboot) and fuses
+bootloader.hex:
+	wget -O $@ https://github.com/Optiboot/optiboot/raw/master/optiboot/bootloaders/optiboot/optiboot_atmega328.hex
+
+bootloader: bootloader.hex
+	avrdude -p $(DEVICE) -c usbtiny -U lfuse:w:0xff:m -U hfuse:w:0xda:m -U efuse:w:0x05:m -U flash:w:$<:i
 
 # create main target firmware
 compile: $(TARGET).elf
@@ -83,11 +87,15 @@ lst: $(TARGET).lst
 map: $(TARGET).map
 
 # compile source files
-%.o: %.c %.h
+%.o: %.c
 	$(CC) $(CFLAGS) -c -o $@ $<
 
+%.o: %.S
+	$(CC) $(AFLAGS) -c -o $@ $<
+
 # link compiled files
 %.elf: $(OBJ)
+	$(info elf)
 	$(CC) $(LDFLAGS) -o $@ $^
 
 $(TARGET).map: $(OBJ)