#============= MCU選擇 ===========================
# MCU name
MCU = atmega8

#============= 輸出格式選擇 ======================
# Output format. (can be srec, ihex)
FORMAT = ihex

#============= 目標文件名(不帶擴展名) ============
# Target file name (without extension).
TARGET = main

#============= 優(yōu)化級別選擇 ======================
# Optimization level (can be 0, 1, 2, 3, s)
# (Note: 3 is not always the best optimization level. See avr-libc FAQ)
OPT = s

#============= C 源文件列表(""為換行符號) =======
# List C source files here. (C dependencies are automatically generated.)
SRC = $(TARGET).c timer.c extdrv.c adc.c sd2k.c mylib.c

#============= ASM 源文件列表 ====================
# List Assembler source files here.
ASRC =

#============= C編譯選項 =========================
# Optional compiler flags.
CFLAGS = -g -O$(OPT) -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -Wa,-ahlms=$(<:.c=.lst)

#============= 匯編器選項 ========================
# Optional assembler flags.
ASFLAGS = -Wa,-ahlms=$(<:.s=.lst), -gstabs

#============= 連接器選項 ========================
# Optional linker flags.
LDFLAGS = -Wl,-Map=$(TARGET).map,--cref

#============= 附加庫選項 ========================
# Additional library flags (-lm = math library).
LIBFLAGS = -lm

#***********************************************************************************
# WinAVR Sample makefile (c) 2002-2003 Eric B. Weddington
# Released to the Public Domain
# Please read the make user manual!
#
# On command line:
# make all = Make software. 編譯
# make clean = Clean out built project files. 清除以前編譯生成的文件
# make coff = Convert ELF to COFF using objtool. 轉換elf文件為cof文件
#
# To rebuild project do make clean then make all.
#
#***********************************************************************************

#============= 指定目錄，如果需要 ================
# Define directories, if needed.
DIRAVR = c:/ele/winavr
DIRAVRBIN = $(DIRAVR)/bin
DIRAVRUTILS = $(DIRAVR)/utils/bin
DIRINC = .
DIRLIB = $(DIRAVR)/avr/lib

#============= 定義命令(工具軟件名稱) ============
# Define programs and commands.
SHELL = sh
CC = avr-gcc
OBJCOPY = avr-objcopy
OBJDUMP = avr-objdump
REMOVE = rm -f
COPY = cp
ELFCOFF = objtool

#============= 一些字符串的定義和數(shù)據(jù)的取得 =======
HEXSIZE = @avr-size --target=$(FORMAT) $(TARGET).hex
ELFSIZE = @avr-size $(TARGET).elf

FINISH = @echo Errors: none
BEGIN = @echo -------- begin --------
END = @echo --------end--------

#============== 指定所有的連接文件 ================
# Define all object files.
OBJ = $(SRC:.c=.o) $(ASRC:.s=.o)

#============== 指定所有的列表文件 ================
# Define all listing files.
LST = $(ASRC:.s=.lst) $(SRC:.c=.lst)

#============== 指定全部.d文件 ====================
# Define all listing files.
ALLD = $(SRC:.c=.d) $(ASRC:.c=.d)

#============== 編譯所有可選的和必須的選項標志，增加處理標志 =
# Combine all necessary flags and optional flags. Add target processor to flags.
ALL_CFLAGS = -mmcu=$(MCU) -I. $(CFLAGS)
ALL_ASFLAGS = -mmcu=$(MCU) -I. -x assembler-with-cpp $(ASFLAGS)
ALL_LDFLAGS = -mmcu=$(MCU) $(LDFLAGS)

#============== 默認的處理(指執(zhí)行make時，相當于執(zhí)行make all),真正的編譯過程,超級重要,要看懂!!! ==
# Default target.
all: begin gccversion sizebefore $(TARGET).elf $(TARGET).hex $(TARGET).eep $(TARGET).lss $(TARGET).cof sizeafter finished end
#開始->gcc版權信息>舊文件大小>編譯生成.elf----->生成.hex----->生成.eep----->生成.lss----->生成.cof>新文件大小--->完成>結束

#***********************************************************************************
#============== 待輸出的一些編譯信息 =============
# Eye candy.
begin:
$(BEGIN)

finished:
$(FINISH)

end:
$(END)

#============== 顯示文件的大小信息(先前的和之后的) ==
# Display size of file.
sizebefore:
@echo Size before:
-$(HEXSIZE)

sizeafter:
@echo Size after:
$(HEXSIZE)

#=============== 顯示編譯版本信息 ===================
# Display compiler version information.
gccversion :
$(CC) --version

#=============== 功能：轉換ELF文件為COFF文件，以便在AVR Studio 中仿真/調試。==
# Target: Convert ELF to COFF for use in debugging / simulating in AVR Studio.
coff: $(TARGET).cof end
%.cof: %.elf
$(ELFCOFF) loadelf $< mapfile $*.map writecof $@

#=============== 從ELF輸出文件中生成最終的輸出文件(.hex,.eep) ==
# Create final output files (.hex, .eep) from ELF output file.
%.hex: %.elf
$(OBJCOPY) -O $(FORMAT) -R .eeprom $< $@

%.eep: %.elf
-$(OBJCOPY) -j .eeprom --set-section-flags=.eeprom="alloc,load" --change-section-lma .eeprom=0 -O $(FORMAT) $< $@

#=============== 從ELF輸出文件中生成擴充的列表文件(.lss) ==
# Create extended listing file from ELF output file.
%.lss: %.elf
$(OBJDUMP) -h -S $< > $@

#=============== 連接：從OBJ文件中生成ELF文件(.elf) ==
# Link: create ELF output file from object files.
.SECONDARY : $(TARGET).elf
.PRECIOUS : $(OBJ)
%.elf: $(OBJ)
$(CC) $(ALL_LDFLAGS) $(OBJ) $(LIBFLAGS) --output $@

#=============== 編譯：從C源文件中生成OBJ文件(.o) ==
# Compile: create object files from C source files.
%.o : %.c
$(CC) -c $(ALL_CFLAGS) $< -o $@

#=============== 匯編：從匯編源文件中生成OBJ文件(.o) ==
# Assemble: create object files from assembler source files.
%.o : %.s
$(CC) -c $(ALL_ASFLAGS) $< -o $@

3=============== 功能：清除上次編譯結果 ==
# Target: clean project.
clean: begin clean_list finished end

clean_list :
$(REMOVE) $(TARGET).hex
$(REMOVE) $(TARGET).eep
$(REMOVE) $(TARGET).obj
$(REMOVE) $(TARGET).cof
$(REMOVE) $(TARGET).elf
$(REMOVE) $(TARGET).map
$(REMOVE) $(TARGET).obj
$(REMOVE) $(TARGET).a90
$(REMOVE) $(TARGET).sym
$(REMOVE) $(TARGET).lnk
$(REMOVE) $(TARGET).lss
$(REMOVE) $(TARGET).cof
$(REMOVE) $(OBJ)
$(REMOVE) $(LST)
$(REMOVE) $(ALLD)


#==================================================================
# Automatically generate C source code dependencies. (Code taken from the GNU make user manual.)
# Note that this will work with sh (bash) and sed that is shipped with WinAVR (see the SHELL variable defined above).
# This may not work with other shells or other seds.
#%.d: %.c
#set -e; $(CC) -MM $(ALL_CFLAGS) $< #| sed 's/$?.o[ :]*/1.o $@ : /g' > $@; #[ -s $@ ] || rm -f $@

# Remove the '-' if you want to see the dependency files generated.
#-include $(SRC:.c=.d)

# Listing of phony targets.
#.PHONY : all begin finish end sizebefore sizeafter gccversion coff clean clean_list

原文來自winavr的一個makefile的例子，我做的主要修改之處有：

1、make all 增加了cof文件的生成
2、make clean 刪除了*.o等更多文件
3、其它小修改還有..但是我忘了

說明：
make clean :
用于清除上次變編結果(如果*.h的文件改變，一定要先執(zhí)行make clean,再執(zhí)行make all)

make all:
編譯全部(如果只有*,c文件改變，則可以不用執(zhí)行make clean)