OpenOCD vs UDB

OpenOCD provides debugging, in-system programming, and boundary-scan testing for embedded target devices through a debug adapter. It communicates with targets over JTAG or Serial Wire Debug (SWD), and can run as a server for GDB clients. Users can also interact through Telnet or GDB; its Tcl interface is intended for machine interaction, and configuration files can contain commands using the documented Tcl scripting API. The target list includes ARM, MIPS, RISC-V, Xtensa, ARC, AVR32, and other architectures. Release 0.12.0 notes support for Espressif ESP32, ESP32-S2, ESP32-S3 cores, and Raspberry Pi Pico RP2040, along with Zephyr and a no-RTOS option. OpenOCD supports remote debugging and exception breakpoints. It is free and listed for Linux, macOS, Windows, and self-hosted setups. The project says it is packaged in popular operating-system repositories and provides access to source code; community binaries are marked unofficial. Host configuration may take extra steps: Linux usually needs a udev rule for adapter access, and Windows requires driver configuration for each peripheral.

UDB has no write-up on Specifiction yet; its figures are above.