A Rust ESP stack trace decoder that can also runs in your browser thanks to WebAssembly

ESP Stack Trace Decoder

A Rust ESP stack trace decoder that can also runs in your browser thanks to WebAssembly.

It is composed of a ⌨️ Rust library, a 💻 Rust command line tool, and a 🌏 WebAssembly library with a HTML interface.

Web tool

The web tool is hosted on Github Pages here.

It is taking your .elf firmware and the stack trace, and outputs the list of functions and their locations, without uploading any of your data anywhere.

Everything run in your browser, ✨ just like that ✨ .

You can also deploy it yourself by hosting the content of the pre-compiled package esp_exception_decoder_wasm.tar.gz on the release page, or by compiling the library in WebAssembly using wasm-pack:

# Install the Rust toolchain by following the latest instructions from here: https://www.rust-lang.org/tools/install
# Install wasm-pack by following the latest instructions from here: https://rustwasm.github.io/wasm-pack/installer
# Build the WebAssembly library
wasm-pack build --target web --out-dir web/

Note that only the index.html, esp_exception_decoder_rs.js and esp_exception_decoder_rs_bg.wasm from the web/ directory are necessary.

Then you can host the content of the web/ directory on any HTTP server.

Here you can find a lot of different ways of starting a simple HTTP server that can be used to serves the web/ folder: http://gist.github.com/willurd/5720255

Opening the index.html file from your filesystem in your browser will not work since we can't include JavaScript files without a HTTP server due to default CORS policy.

Command line tool

A bit more boring command line tool is also available:

Get the latest binary release here: Releases

Or build it yourself:

# Install the Rust toolchain by following the latest instructions here: https://www.rust-lang.org/tools/install
# Build the command line binary    
cargo build --release

To run the command line tool, make sure that the binary is executable:

chmod +x esp_exception_decoder

Then execute it like this, replacing firmware.elf with your .elf firmware and stack_trace.txt with the stack trace from your ESP:

./esp_exception_decoder firmware.elf stack_trace.txt

You can also ommit the stack trace file and use the standard input instead:

cat stack_trace.txt | ./esp_exception_decoder firmware.elf

Or even use the tool semi-interactively by running the program without the stack trace file parameter, pasting the stack trace and pressing CTRL+D:

./esp_exception_decoder firmware.elf
# The program is executing but not displaying anything
# Paste the stack trace here
# Then press CTRL+D