ctxLink is an open source, open hardware, wireless debugging probe
for the majority of ARM Cortex-M microcontrollers. With a built-in
GDB server, it supports full source-level debugging of embedded
systems – through SWD or JTAG – using GDB or any GDB-compatible
debugging software.

You can connect your computer to the debugger over a USB serial connection or using the built-in Wi-Fi module. ctxLink can be powered through a USB connection, by the target system, or using an optional LiPo battery, which you can recharge thanks to the on-board power management circuit. You can even power your target system from the probe itself.