Optiboot compilation problem in ATmega328

Dear all

I compiled optiboot OS found in Arduino folder in my pc in the Atmel studio 6.
i have error with my compilation, error is of F_CPU.
i am attaching here photo of the error place.

PC OS - windows 8
software - Atmel studio 6.2
optiboot os - Arduino-1.0.5

please help me.
thanks in advance.