espwlmon

Tool for reading the status of wear leveling layer in flash memories in ESP32-xx SoCs, modules and boards.

Project includes an extended version of base wear leveling which makes possible long term tracking of per sector erase counts and improves leveling evenness by address mapping randomization using format preserving encryption based on unbalanced 3-stage Feistel network.

Installation and usage

0. Prerequisites and cloning

• Set up ESP-IDF on your system. Currently the only tested version is v5.0. For instructions see Espressif's get started guide
• Get yourself a Python3 installation with tkinter for running the GUI part of this project. This will heavily depend on your system and current installations/configurations, so you're on your own for this one

Once ready to proceed, clone this repo

git clone https://github.com/omnitex/espwlmon.git && cd espwlmon

1. Get WL_Advanced

Copy the contents of data-collector/wear_levelling directory to $IDF_PATH/components/wear_levelling directory in your active ESP-IDF installation.

cp -r data-collector/wear_levelling/ $IDF_PATH/components/

2. Erase current flash contents

idf.py requires to be run from ESP-IDF buildable project folder; for such the erase_stress_example from the next step can be used

idf.py erase-flash

This will allow WL_Advanced to initialize all structures in flash from a clean state.

2a. Test with erase_stress_example

Warning: Running this will repeatedly perform erases in flash memory of you device, (really) slowly wearing it out.

cd erase_stress_example && idf.py flash monitor

The provided example is a simple project for testing FAT read/write + memory erase stressing which builds up WL_Advanced records about sector erases in flash.

Letting it run fully will take some time. Feel free to stop it after at least a run or two (see the logs while it runs) and move onto step 3. But keep in mind the longer it runs the better - at least for visualization in step 4.

2b. Run your own project

Instead of running the stress example, you can supply your own project for this step. Only requirement is that it uses the wear leveling layer and has enabled the advanced version of WL in menuconfig.

cd <FOLDER OF YOUR PROJECT>
idf.py menuconfig
Navigate to Component config/Wear Leveling => enable advanced monitoring mode
(or jump to symbol WL_ADVANCED_MODE using /)

3. Flash embedded data collector

After running some code on top of WL_Advanced, it's time to read out the WL status.

cd $IDF_PATH/components/wear_levelling/wlmon && idf.py app-flash

This will flash the embedded part of the monitoring tool to your device. Making it ready for the final step.

4. Run PC side Python GUI

Navigate back to the root of this repo, wherever you've cloned it and run the following.

python3 -m pip install -r requirements.txt
python3 espwlmon.py --port PORT

After installing required Python packages, run espwlmon.py while specifying the serial port your device is connected to.

And that's it; you should be greeted with a listing of internal structures used by WL and an erase count heatmap, as reconstructed from records in flash.