Best of Embedded Systems — June 2025

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   Hacker News·52w

   Root Shell on Credit Card Terminal

   A security researcher reverse engineered a Worldline Yomani XR payment terminal and discovered an exposed root shell accessible via serial console without authentication. Despite sophisticated tamper detection mechanisms using pressure-sensitive connectors and copper traces, the debug interface remained accessible through an external hatch. The researcher extracted unencrypted firmware using chip-off techniques, revealing an outdated Linux system (kernel 3.6 from 2023). However, the security impact is limited because the Linux system only handles networking and updates, while sensitive payment operations run on a separate, encrypted secure processor.

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   Article

   Hacker News·51w

   Air Lab Simulator

   A web-based simulator that replicates Air Lab firmware functionality, allowing users to interact with virtual environmental sensors through different simulated environments. The simulator includes device controls, USB connectivity simulation, and menu navigation features, providing a hands-on experience without requiring physical hardware.

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   Article

   Lobsters·50w

   r9os/r9: The R9 operating system

   R9 is a reimplementation of the Plan 9 operating system kernel written in Rust. The project supports multiple architectures including x86-64, aarch64, and RISC-V, and can be built using cargo with the xtask pattern. It runs on QEMU emulation and has been tested on real hardware like Raspberry Pi 4. The project includes detailed build instructions, runtime dependencies, and setup guides for both emulated and physical hardware deployment.

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   Article

   Hacker News·50w

   A developer toy from PostHog

   PostHog introduces DeskHog, an open-source handheld gaming device built around an ESP32-S3 microcontroller with a color TFT display, WiFi connectivity, and 10-hour battery life. The palm-sized device features a custom 3D-printed case and comes with several pre-built games including Pong variants, idle clickers, and roguelike adventures. Developers can create their own games using AI editors or C++, and the device can connect to PostHog for displaying analytics data. The hardware includes expansion ports for additional functionality and all design files are available on GitHub for DIY builders.

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