OllyDbg vs OpenOCD

OllyDbg is a free 32-bit assembler-level debugger for Microsoft Windows, intended for binary analysis when source code is unavailable. It traces registers and identifies procedures, loops, API calls, switches, tables, constants, and strings. The debugger can load DLLs, attach to running programs, and handle multithreaded applications. Breakpoint types include conditional, logging, memory, and hardware breakpoints; execution tracing can log arguments for known functions. Patches can be retained between sessions, written back to executable files, and used to update fixups. An open architecture supports third-party plugins, and the maker provides a Plugin Development Kit with documented samples. Listed requirements include Windows 95, 98, NT 4.0, 2000, or higher; Win32s is unsupported. Development is frozen, and the 64-bit version is incomplete. Registration is free and requested for permanent or commercial use. The maker says original versions 1.00–1.10 do not communicate with other computers except for remote files specified by the user.

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.