關於 avr compile .elf error 的問題

hseinhsein1314

../LCDTest.c:6: warning: return type of 'main' is not 'int'
../test.c:40: warning: return type of 'main' is not 'int'
avr-gcc -mmcu=atmega8  LCDTest.o lcd.o test.o     -o LCDTest.elf
test.o: In function `main':
C:\Users\Terence\Desktop\AVR tutorial\LCD hex\lcd\Sample\default/../test.c:41: multiple definition of `main'
LCDTest.o:\Users\Terence\Desktop\AVR tutorial\LCD hex\lcd\Sample\default/../LCDTest.c:7: first defined here
make: *** [LCDTest.elf] Error 1
Build failed with 1 errors and 2 warnings...

我跟着online的教法，把 libm.a加進library裡，但是還是沒有解決～
我的是 avr studio 4.16.

謝謝