OMAPL138 LCDK interrupt timer2

Hello, OMAPL138 experts, I am a student and develop on the OMAPL138 lcdk board (Connection to Computer is a Blackhawk USB560 v2 System Trace).
I just started to develope (NO SYS BIOS) on the OMAPL138. So I tried everything out like UART(send text to the console -Putty- to the Computer)
or when i press the user button3 the LED turns off...

Now I tried to do something with interrupts I want to use the Timer2 set a flag and in the main() I do something if the flag is set...
I tried the examples from the OMAPL138_StarterWare_1_10_04_01 and quickStartOMAPL1x_rCSL but nothing works. (I'm sitting here now 2 weeks and nothing works.)

Now to my Question. Is there an step by step example what i have to do for an ISR (Set Clock, Set TimerFlag(IFR)...)?

Regards,

Fernando