Black Magic Probe is a sophisticated JTAG and SWD adapter supporting
flashing and debugging some Cortex-M3 microcontrollers, in particular
the STM32 family. blacksphere.co.nz
It integrates a GDB server and exposes it over a standard ACM
channel. Just plug it in and connect with gdb, no extra software or
If you want to try it for cheap, you can reflash any ST-Link with a
version from github.com built with "make
PROBE_HOST=stlink" by using another SWD-capable programmer (desolder
the "DEFAULT" bridges, solder "PRG-32", use CN3 for flashing).
But if you want to get the full functionality (including
DFU-upgradeable probe firmware, an additional auxilary UART, full JTAG
support and experimental SWO), read on about more hardware hacking in
the follow-up post.