Common Makefile for all avr C projects

Makefile

##########------------------------------------------------------##########
##########              Project-specific Details                ##########
##########    Check these every time you start a new project    ##########
##########    or when you change your MCU or USB PORT           ##########
##########------------------------------------------------------##########

MCU   = atmega8       ## Name of your microcontroller device.
F_CPU = 8000000UL  		## Frequency
BAUD  = 19200		    	## BAUD rate
PORT = /dev/ttyUSB0		## USB PORT of your computer


##########------------------------------------------------------##########
##########                 Programmer Defaults                  ##########
##########          Set up once, then forget about it           ##########
##########------------------------------------------------------##########

PROGRAMMER_TYPE = avr910
PROGRAMMER_ARGS = -b $(BAUD) -P $(PORT)
# extra arguments to avrdude: baud rate, chip type, -F flag, etc.

##########------------------------------------------------------##########
##########                  Program Locations                   ##########
##########     Won't need to change if they're in your PATH     ##########
##########------------------------------------------------------##########

CC = avr-gcc
OBJCOPY = avr-objcopy
OBJDUMP = avr-objdump
AVRSIZE = avr-size
AVRDUDE = avrdude


##########------------------------------------------------------##########
##########                   Makefile Magic!                    ##########
##########        Summary:                                    	##########
##########        We want a .hex file                        		##########
##########        Compile source files into .elf                ##########
##########        Convert .elf file into .hex                   ##########
##########        You shouldn't need to edit below.             ##########
##########------------------------------------------------------##########

## The name of your project (without the .c)
# TARGET = name it automatically after the enclosing directory
TARGET = $(lastword $(subst /, ,$(CURDIR)))


# Object files: will find all .c/.h files in current directory.
# If you have any other (sub-)directories with code,
# you can add them in to SOURCES below in the wildcard statement.
SOURCES=$(wildcard *.c)
OBJECTS=$(SOURCES:.c=.o)
HEADERS=$(SOURCES:.c=.h)


## Compilation options, type man avr-gcc if you're curious.
CPPFLAGS = -DF_CPU=$(F_CPU) -DBAUD=$(BAUD)
CFLAGS = -Os -g -std=gnu99 -Wall
## Use short (8-bit) data types 
CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums 
## Splits up object files per function
CFLAGS += -ffunction-sections -fdata-sections 
LDFLAGS = -Wl,-Map,$(TARGET).map 
## Optional, but often ends up with smaller code
LDFLAGS += -Wl,--gc-sections 
## Relax shrinks code even more, but makes disassembly messy
## LDFLAGS += -Wl,--relax
## LDFLAGS += -Wl,-u,vfprintf -lprintf_flt -lm  ## for floating-point printf
## LDFLAGS += -Wl,-u,vfprintf -lprintf_min      ## for smaller printf
TARGET_ARCH = -mmcu=$(MCU)

## Explicit pattern rules:
##  To make .o files from .c files 
%.o: %.c $(HEADERS) Makefile
	 $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -o $@ $<;

$(TARGET).elf: $(OBJECTS)
	$(CC) $(LDFLAGS) $(TARGET_ARCH) $^ $(LDLIBS) -o $@

%.hex: %.elf
	 $(OBJCOPY) -j .text -j .data -O ihex $< $@

%.eeprom: %.elf
	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O ihex $< $@ 

%.lst: %.elf
	$(OBJDUMP) -S $< > $@

## These targets don't have files named after them
.PHONY: all disassemble disasm eeprom size clean squeaky_clean flash fuses

all: $(TARGET).hex 

debug:
	@echo
	@echo "Source files:"   $(SOURCES)
	@echo "MCU, F_CPU, BAUD:"  $(MCU), $(F_CPU), $(BAUD)
	@echo	

# Optionally create listing file from .elf
# This creates approximate assembly-language equivalent of your code.
# Useful for debugging time-sensitive bits, 
# or making sure the compiler does what you want.
disassemble: $(TARGET).lst

disasm: disassemble

# Optionally show how big the resulting program is 
size:  $(TARGET).elf
	$(AVRSIZE) -C --mcu=$(MCU) $(TARGET).elf

clean:
	rm -f $(TARGET).elf $(TARGET).hex $(TARGET).obj \
	$(TARGET).o $(TARGET).d $(TARGET).eep $(TARGET).lst \
	$(TARGET).lss $(TARGET).sym $(TARGET).map $(TARGET)~ \
	$(TARGET).eeprom

squeaky_clean:
	rm -f *.elf *.hex *.obj *.o *.d *.eep *.lst *.lss *.sym *.map *~ *.eeprom


##########------------------------------------------------------##########
##########              Programmer-specific details             ##########
##########           Flashing code to AVR using avrdude         ##########
##########------------------------------------------------------##########

flash: $(TARGET).hex 
	$(AVRDUDE) -x no_blockmode -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -U flash:w:$<

## An alias
program: flash

flash_eeprom: $(TARGET).eeprom
	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -U eeprom:w:$<

avrdude_terminal:
	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -nt