Find a description how to modify a Discovery Board to use it's Stlink as
black magic debug at
http://embdev.net/articles/STM_Discovery_as_Black_Magic_Probe

Differences between V1/V2

                V1                V2
ID Pins PC13/14 unconnected       PC 13 pulled low
LED STLINK      PA8, active High  PA9, Dual Led
MCO Out         NA                PA8
RESET(Target)   T_JRST(PB1)       NRST (PB0)