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JTAG

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The JTAG interface in MACOBOX allows you to interact directly with the CPU or microcontroller of a target device, giving you access to low-level debugging, memory dumping, and device control features.

It’s a powerful tool for reverse engineering, firmware extraction, and advanced hardware analysis.

To use JTAG with the Bruschetta Board, make sure to set the DIP switches to:

Mode 4 → S1 = ON, S2 = ON

This enables the UART1 + JTAG configuration.
Improper mode selection may result in no response from the target device. If the mode is correct but the connection fails to start, try to unplug bruschetta and plug it again.

Just like other modules, the JTAG page is divided into two main sections

JTAG Interaction Interface #

In the top section, you’ll find the interface used to interact with the connected device.

Starting a Session #

  • Before starting, make sure to upload the proper OpenOCD config file (check settings page) for your target device.
  • Then, press the Start button.

MACOBOX will automatically:

  • Launch OpenOCD
  • Open a telnet session

This entire process is handled automatically — no need to manually run OpenOCD or open a terminal, as you would on a traditional setup.

Once active, you can send commands to the target directly via the JTAG interface.

Command Shortcuts #

Below the input bar, you’ll find a dropdown menu with a set of default commands.
Select one to insert it into the input field, ready to send with a single click.

Image Dump Functionality #

The image dump tool allows you to extract raw memory regions from the device.

You can choose between two options:

  1. Manual Dump
    • Enter the filename, start address, and end address (or size)
    • Click Run Dump to begin the extraction
  2. Auto Extract from UART Logs
    • Select a previously saved UART log (from the UART page)
    • MACOBOX will parse the log, extract memory addresses, and automatically compute the dump size
    • Click Run Dump to proceed

⚠️ Note: Dumping memory can take a long time. Do not leave the page while the operation is running.

Output Tabs #

In the bottom section, you’ll find:

Dumps #

All memory dumps created via the dump_image command will appear here.
You can download them, associate them with a project, or analyze them using other tools inside MACOBOX.

Logs #

This tab stores all logs related to the JTAG command session, if saved.