Undefined symbol

I can not compile a very simple PWM program on Keil The same program is compiled on Energia The message that I get is below: For your information main.c is in the source file and I use C not C++....
Undefined symbol

I can not compile a very simple PWM program on Keil The same program is compiled on Energia The message that I get is below: For your information main.c is in the source file and I use C not C++....
Undefined symbol

I can not compile a very simple PWM program on Keil The same program is compiled on Energia The message that I get is below: For your information main.c is in the source file and I use C not C++....
Undefined symbol

I can not compile a very simple PWM program on Keil The same program is compiled on Energia The message that I get is below: For your information main.c is in the source file and I use C not C++....
Undefined symbol

I can not compile a very simple PWM program on Keil The same program is compiled on Energia The message that I get is below: For your information main.c is in the source file and I use C not C++....