Basic Makefile for AVR development on OS X using CrossPack (http://www.obdev.at/products/crosspack/index.html).

Makefile

# Basic AVR Makefile
# Author: Zachary Voase
# License: Public Domain <http://unlicense.org/>
#
# Configured to work with the Arduino Uno R3, programmed from a Mac, using
# CrossPack (http://www.obdev.at/products/crosspack/index.html).

# This needs to be the TTY device on your Mac at which the Arduino is mounted.
# Mine is normally either 1421 or 1411.
PORT       = /dev/tty.usbmodem1421

# Consult Arduino.app/Contents/Resources/Java/hardware/arduino/boards.txt for
# values to use for these configuration parameters.
DEVICE     = atmega328p
F_CPU      = 16000000
AVRDUDE    = avrdude -c arduino -P $(PORT) -p $(DEVICE)

# These probably need to be left alone unless you know what you're doing.
AR=avr-ar
AS=avr-as
CC=avr-gcc
CXX=avr-g++
CFLAGS=-Wall -Os -DF_CPU=$(F_CPU) -mmcu=$(DEVICE) \
  		 -I/usr/local/CrossPack-AVR/avr/include/


.PHONY: all flash fuse install load clean

all:	main.hex

flash:	main.hex
	$(AVRDUDE) -U flash:w:main.hex:i

clean:
	rm -f main.hex main.elf *.o

# This will be made by an implicit Make rule.
main.o: main.c

main.elf: main.o
	$(CC) $(LDFLAGS) -o $@ $^

main.hex: main.elf
	rm -f main.hex
	avr-objcopy -j .text -j .data -O ihex main.elf main.hex
	avr-size --format=avr --mcu=$(DEVICE) main.elf
# If you have an EEPROM section, you must also create a hex file for the
# EEPROM and add it to the "flash" target.