Black Magic Debug vs pyOCD

Black Magic Debug is a free JTAG/SWD debugger for embedded microcontrollers, aimed at professional developers who want control over build systems and testing environments. Its firmware includes a GDB server that detects targets automatically, without target-specific configuration scripts. Debugging tools include watchpoints, flash memory breakpoints, memory and register examination, and flash programming. The project describes support for ARM Cortex-M and Cortex-A microcontrollers; its listed target platforms also include RISC-V, and remote debugging is supported. The probe connects as a standard USB CDC ACM virtual serial device, with no special driver needed for this interface on Linux or macOS. The debugger works with Linux, macOS, and Windows. The GDB server also supports semihosting and host I/O, Serial Wire Output, and USB DFU firmware upgrades. Documentation includes guides for PlatformIO and STM32CubeIDE. It can also be compiled as a desktop application and used with BMP, ST-Link, FTDI-MPSSE, SEGGER J-Link, or CMSIS-DAP adapters. Desktop-app programming is a little slower, though BMP development may be faster because firmware upload is unnecessary. Getting started requires a Black Magic Probe and a suitable target toolchain.

pyOCD is a Python tool and API for debugging, programming, and exploring Arm Cortex microcontrollers. Its GDB server supports command-line debugging and IDE workflows, including Arm CMSIS Debugger, Cortex-Debug, and Eclipse Embedded CDT. It can program firmware and data images into internal or external flash, or load images into RAM. The Python API controls target devices and can support CI setups and custom test or debug tools. More than 70 common Arm Cortex-M devices have built-in support, with CMSIS Device Family Packs available for additional devices. Features include semihosting, SWV, and CMSIS-Pack support. Built-in probe plug-ins include CMSIS-DAP, Raspberry Pi Picoprobe, SEGGER J-Link, STLink, and pyOCD remote; PE Micro Cyclone and Multilink require a separate plug-in. A server and client can share probes over TCP/IP. pyOCD requires Python 3.9 or later and runs on macOS, Linux, FreeBSD, and Windows. It is free, with code licensed under Apache 2.0. Unlocking a supported locked device can require a mass erase, which erases its data.