ITM Parser

itm-parser is a command-line tool for parsing and formatting ITM (Instrumentation Trace Macrocell) output. It simplifies debugging by converting raw ITM messages into human-readable ASCII text, working seamlessly with probe-rs in the background.

Note: itm-parser internally uses probe-rs. Ensure probe-rs is installed before using this tool.

Features

• Parses ITM Instrumentation packets (e.g., Ok(Instrumentation { port: 0, payload: [...] })).
• Decodes payloads into readable ASCII text.
• Supports newline characters (\n) in payloads for proper log message formatting.

Installation

Step 1: Install probe-rs

itm-parser relies on probe-rs to interact with your embedded device. Install probe-rs using Cargo:

cargo install probe-rs-tools

Step 2: Install itm-parser

Once probe-rs is installed, install itm-parser:

cargo install itm-parser

Usage

Run the itm-parser command with required arguments. Internally, it uses probe-rs itm swo to interact with your embedded device.

Command Syntax

itm-parser --chip <CHIP> [--probe <VID:PID>]  --connect-under-reset <DURATION> <CLOCK> <BAUD>

Arguments

1. --chip (required): The target chip identifier (e.g., STM32F303CC).
2. --probe VID:PID (optional): The VID:PID of the debug probe to use (e.g., 0483:374b). If omitted, the default probe will be used. To get VID:PID of the probe run the command `probe-rs list'
3. --connect-under-reset flag tells the debugger (in this case, probe-rs) to hold the target MCU in reset while it is establishing a debug connection. So you have to press the reset button of the board to run the code.
4. (required): Duration of the trace in milliseconds.
5. (required): Clock speed feeding the TPIU/SWO module in Hz.
6. (required): Desired baud rate for SWO output.

Example

itm-parser --chip STM32F303CC --connect-under-reset 10000 8000000 1000000

Output

If the raw ITM packets contain:

Ok(Instrumentation { port: 0, payload: [72, 101, 108, 108, 111, 10] })
Ok(Instrumentation { port: 0, payload: [87, 111, 114, 108, 100, 10] })

itm-parser will decode and display:

Hello
World