-debugio=bkpt
-debugio=dcc
-debugio=mempoll
Specifies the debugio implementation to link with. The default for architectures that have the ARM instruction set will use dcc and architectures that have only the Thumb-2 instruction set will use mempoll.
The following selects the breakpoint debugio implementation for a cortex-m3 cpu
cc -cpu=Cortex-M3 -debugio=bkpt …