The Gistre Blog

Launching the Gistre blog

Wed, 04 Feb 2026 11:20:10 +0000

Explaining the GISTRE Blog, why it exists the whereabout and more.

Centimeter level accurate localization using open-source library and free to use antenna network

Tue, 13 Jan 2026 09:52:54 +0000

An introduction to the RTK technology and a short tutorial on how to use the open source RTKLib library and the free to use antenna network Centipède in order to track the position of a rover in real-time with centimeter level accuracy.

Deferred logging from scratch

Tue, 06 Jan 2026 12:39:32 +0000

As our machines become faster and faster, we generally don’t think anymore about the cost of printing and formatting strings. What if we defer the formatting work to the host ? The formatting code and the string messages no longer need to be stored on device. Thus, reducing the CPU, RAM and Flash requirements and increasing battery life.

Investigating How Windows Works: How Do Applications Draw on Your Screen?

Fri, 19 Dec 2025 14:49:27 +0000

The goal of this article is to explain to the general public how their computer applications work.

Game launch process on Nintendo: From cartridge to execution

Tue, 16 Dec 2025 07:38:30 +0000

This article will explain the interaction between the game cardridge and the firmware of a Nintendo 3DS.

What is in your GPU?

Fri, 12 Dec 2025 10:50:22 +0000

This topic explores GPU architecture and CUDA programming, focusing on three key aspects. First, it discusses the SIMT (Single Instruction, Multiple Threads) block-based architecture and how CUDA kernels leverage this parallelism. Second, it covers memory, for efficient data access. Finally, it examines hardware and software synchronization methods, such as barriers, essential for coordinating thread execution in parallel computing.

An introduction to JIT compilation for video game console CPU emulation

Tue, 09 Dec 2025 08:20:04 +0000

This article introduces the concept of Just-In-Time (JIT) compilation and its application to the domain of game console emulation. Advantages and weaknesses of JIT compared to the traditional interpreter are covered as well.

Funky File Formats: Polyglot Files and Angecryption

Fri, 05 Dec 2025 09:54:03 +0000

A deep dive into Ange Albertini-style funky file format covering Polyglots or Angecryption.

Understanding memory management within Linux: from malloc() to /proc

Tue, 02 Dec 2025 10:01:18 +0000

Explain how a program manages its memory within Linux, from the call to malloc() to the use of memory pages via mmap(), using the /proc tools and concrete visualizations.

Why rm Doesn't Truly Delete Files -- And How to Do It Safely with shred

Tue, 25 Nov 2025 17:35:23 +0000

This article explains why using rm on Linux doesn’t truly erase files and how tools like extundelete can recover them. It introduces shred as a safer alternative for secure deletion and contrasts behavior on ext4 with modern copy-on-write filesystems like Btrfs and ZFS.

Reverse Engineering a USB Device in Linux

Sat, 22 Nov 2025 09:24:22 +0000

Explore how to reverse engineer a USB device’s communication protocol using tools like lsusb, usbmon, and Wireshark, then implement a custom Linux kernel driver to handle its input/output by directly interfacing with its USB endpoints. The driver will specifically target the DualShock 4 controller.

A History of Anti-Cheat Techniques in Video Games, from Server-Side Code to Kernel Level

Wed, 19 Nov 2025 07:38:42 +0000

A discovery of the evolution of anti-cheating technolgies over the years

Writing an OS in Rust: Bootloader #1

Fri, 14 Nov 2025 09:29:55 +0000

A brief introduction to building a custom operating system in Rust, starting with the bootloader. This article covers setting up the development environment, creating a minimal bootable kernel, and understanding how the boot process works at a low level.

Mobile payment: NFC, OS, applications... what's behind a transaction?

Tue, 11 Nov 2025 10:35:44 +0000

Using the example of mobile payment, the idea is to understand how NFC works and how it interacts with other system layers.

Systèmes embarqués dans l’aéronautique : entre précision, sécurité et innovation

Fri, 07 Nov 2025 16:26:00 +0000

Les systèmes embarqués sont au cœur de l’aéronautique moderne.

Linux networking internals: Netfilter

Tue, 04 Nov 2025 08:26:29 +0000

Deep dive into Netfilter, the packet filtering framework of the Linux kernel

Running Windows x86 application builds on a ARM64 macOS

Tue, 28 Oct 2025 08:15:22 +0000

This article will explore how applications compiled for the x86 architecture can be executed on macOS systems running on ARM64 hardware. The objective is to understand why we need tools for it, and to dissect different existing solutions.

Beyond basics exploring c metaprogramming and compile time techniques

Fri, 24 Oct 2025 07:14:06 +0000

This article will explore advanced C++ metaprogramming techniques

Explore video memory by creating your own screen sharing

Tue, 21 Oct 2025 10:34:17 +0000

This article explains how graphical display works on Linux — from the framebuffer all the way to the screen. It details the role of the kernel (DRM, GEM, KMS), the graphics compositor, and userland technologies like xdg-desktop-portal and PipeWire in the secure handling of video buffers. Finally, a C implementation illustrates how to capture a screenshot and send it to a remote server.

Pourquoi le Bluetooth Low Energy (BLE) a accéléré l'essor de l'IoT ?

Sat, 18 Oct 2025 13:10:03 +0000

Cet article examine comment le Bluetooth Low Energy (BLE), avec son protocole optimisé pour les communications courtes et sa consommation ultra-faible, s’est imposé comme une solution radio efficace et adaptée aux contraintes énergétiques et fonctionnelles de l’IoT.

What is a runner?

Wed, 15 Oct 2025 06:41:21 +0000

In this article, we’ll talk about the concept of a runner, what is it used for. We’ll also dig in the internal mechanisms of two well known types of runners : Gitlab and Celery, both used for different usage.

Understanding and mastering inter-processor communication on STM32MP

Fri, 10 Oct 2025 07:35:00 +0000

The goal of this article is to explain how Inter-Processor Communication (IPC) works using protocols like RPMsg and OpenAMP.

Why is latency between the peripheral and the game engine so important in E-sports?

Tue, 07 Oct 2025 09:09:26 +0000

In this article, I’ll explain why overall system latency can sometimes have dramatic consequences in competition. I’ll cover what makes up peripheral latency, kernel and processor interruption, and how input is taken into account in the game engine.

Understanding Regular Expression Engines: differences between non-deterministic (NFA) and deterministic finite automata (DFA)

Fri, 03 Oct 2025 07:21:45 +0000

This article offers a deep dive into regular expressions, exploring how they work under the hood and how understanding their inner mechanics can help you write safe, more efficient patterns.

How your GPU turns a list of points into a 3D model

Tue, 30 Sep 2025 09:17:23 +0000

An introduction to the 3D graphics pipeline used by GPUs in personal computers. It should walk the reader through the main stages involved in transforming raw geometric data into pixels displayed on screen.

Deep dive into PyO3

Wed, 24 Sep 2025 17:51:08 +0000

Comment fonctionnent les convertions de types Python-Rust

Hiding and retrieving information in PNG file using Steganography

Fri, 19 Sep 2025 12:28:38 +0000

What is steganography and how it could be used to hide and retrieve information ? This article will use the example of a PNG file.

The booting process of the Nintendo DS and its Dual-CPU architecture

Fri, 19 Sep 2025 10:53:40 +0000

Overview of the Dual-CPU architecture of the Nintendo DS, how its BIOS and its firmware work when booted up, and how games are loaded from the cartridge.

La Redstone sur Minecraft et les possibilités techniques

Fri, 12 Sep 2025 12:12:46 +0000

Minecraft, un des jeux-vidéos les plus populaires, utile en GISTRE

Temps réel et volant de F1

Tue, 09 Sep 2025 10:00:00 +0200

Quand un pilote appuie sur un bouton de son volant de F1, que se passe-t-il réellement ? Plongée dans l’univers des systèmes embarqués critiques : de la détection mécanique au bus CAN, en passant par l’ECU et les contraintes temps réel. Une course contre la montre où chaque microseconde compte.

The Future of 3D Printing: From Planar to Non-Planar Slicing

Fri, 05 Sep 2025 10:52:25 +0000

Discuss about the evolution of the 3D printers and what’s coming next.

What happens when you plug in a USB stick ?

Tue, 02 Sep 2025 09:58:14 +0000

This article follows the journey of a USB flash drive from physical connection to user integration.

Building a physics simulation engine in rust

Mon, 07 Jul 2025 07:07:17 +0000

A tutorial on how to make a physics engine from 0 using basic physics theory and Verlet integration

The DWARF Debugging Information Format

Mon, 12 May 2025 09:24:24 +0000

The DWARF debugging Format Requirements For this article we will be using a few different programs to do some tests on the debugging format. To replicate the examples in this article you need: gcc or clang a nice and simple C program readelf and objdump During this article we will be using gcc and clang to compare and do a few experiments. To generate debugging information, you can use the -gdwarf flag in the two compilers to get an ELF file with the right DWARF debugging info in it. I recommend also using -O0 to avoid any problems with optimized out sections of code.

RowHammer vulnerability and how to protect our devices

Fri, 21 Mar 2025 17:18:35 +0000

A Hardware vulnerability in DRAM and its actual solution

Evolution of GPU Architectures and Hardware Graphics Pipeline through Nintendo Consoles - Part 1

Sat, 08 Feb 2025 11:07:49 +0000

This article goes over the evolution of the hardware graphics pipeline on GPUs across the different game console generations.

Evolution of GPU Architectures and Hardware Graphics Pipeline through Nintendo Consoles - Part 2

Sat, 08 Feb 2025 11:07:49 +0000

This article goes over the evolution of the hardware graphics pipeline on GPUs across the different game console generations.

An introduction to MEMS

Mon, 30 Dec 2024 13:45:47 +0000

This article explores the expansive field of MEMS (Micro-Electro-Mechanical Systems), encompassing various types such as sensors, actuators, purely electronic or structural elements.

Nix as a Project Manager

Sat, 21 Dec 2024 16:26:42 +0000

A short tutorial on how to use nix features to easily manage, reproduce and expand your projects.

How are processors made and why their production becomes more complex over the years

Wed, 18 Dec 2024 07:47:45 +0000

Deep dive through the manufacturing process of CPUs and what are the challenges related to it

Navigating the Complexity of Emulating Diverse Microcontroller Architectures Pre Emulation, Part II

Mon, 09 Dec 2024 17:08:57 +0000

An overview of the steps involved in emulating diverse architectures and the challenges encountered throughout the process.

Navigating the Complexity of Emulating Diverse Microcontroller Architectures - Pre-Emulation, Part I

Mon, 02 Dec 2024 12:11:19 +0000

An overview of the steps involved in emulating diverse architectures and the challenges encountered throughout the process.

How to implement our own file system

Mon, 02 Dec 2024 10:19:48 +0000

In this article, we’ll see how to write a simple file system

The Evolution of Gaming on Linux

Thu, 21 Nov 2024 10:29:41 +0000

A dive into the evolution of Linux as a gaming platform over the years, and the technical challenges that were overcome to make gaming viable on the open-source OS.

How perf(1) works, or asking my CPU about their feelings.

Sun, 17 Nov 2024 10:15:00 +0200

Perf is a performance analysis tool for Linux. It instrumentalizes events setup by the kernel to monitor applications. While it makes sense that kernel events are available to a tool implemented inside the kernel, how can perf know about CPU metrics, such as the number of instructions a program executed?

Device communication in embedded systems

Thu, 14 Nov 2024 18:35:00 +0200

This article is about device communication in embedded systems. It will compare and explain the different types of device communication in embedded systems (I2C, UART, SPI, CAN) to beginners who want to learn how device communication works and which one to use.

EUCLEAK : Using side-channel attack to extract secret key from YubiKey 5 Series

Tue, 12 Nov 2024 08:15:00 +0200

This article aims to give an in depth description on EUCLEAK, an attack that was discovered by NinjaLab. Focusing on how side-channels attacks were used to exploit a vulnerability found in ECDSA implementation in YubiKey 5 Series and to reverse engineer the ECDSA algorithm.

The USB keyboard protocol

Sun, 10 Nov 2024 11:15:00 +0200

Introduction to USB keyboard protocol

Implementation of collision avoidance algorithms in real time autonomous vehicles

Sat, 09 Nov 2024 12:00:00 +0200

This article describes the implementation of collision avoidance algorithms in real-time autonomous vehicles.

Chip binning : why your CPU is most likely broken (partially)?

Sun, 03 Nov 2024 18:15:00 +0200

CPU manufacturing is so complex that the chips often have imperfections. Some cores do not work or must run at lower speeds. Manufacturers test them and sell based on performance.

Optimizing regular expressions

Sun, 20 Oct 2024 18:50:00 +0200

This article will explain in detail how to optimize regular expressions. It will explore various techniques to reduce backtracking and improve speed, enabling the writing of more efficient and high-performance regex.

Starlink et l'internet par satellite

Tue, 15 Oct 2024 16:50:00 +0200

Une brève introduction au monde de l’internet par satellite avec une présentation des spécificités de la société Starlink

LadderLeak, comment retrouver une clef privée ECC sur analyse de consommation électrique

Fri, 16 Feb 2024 18:05:00 +0200

Short article to cover the LadderLeak problem for ECC

Developing a Bluetooth application on Linux

Mon, 12 Feb 2024 10:30:00 +0100

Introduction to BlueZ and its API

Why Wayland: A Brief History of Display Protocols

Sun, 11 Feb 2024 10:30:00 +0100

A short introduction to the world of display protocols, detailing parts of the design of the X Window System, its shortcomings and the rise of the Wayland protocol.

Holographic Displays: Your Windshield as a Virtual Assistant

Mon, 05 Feb 2024 18:10:00 +0200

A quick view on how holographic displays aim to aid driving

Random number generation in embedded systems

Mon, 05 Feb 2024 18:00:00 +0200

This article explores the world of random number generation in embedded systems, covering both pseudo-random number generators (PRNGs) and hardware-based random number generators (HRNGs). It explains their principles, provides examples of code, discusses their advantages and limitations, and highlights their applications in embedded systems.

How to write you first kernel

Sun, 07 Jan 2024 16:00:00 +0200

In this article, we’ll write a simple 32bits ‘Hello, World!’ kernel for x86

IMUs and Kalman Filters

Sun, 07 Jan 2024 00:15:45 +0200

How to use an MPU6050 with an STM32 and use an Kalman Filter to measure angles

Why your contactless credit card can't be cloned

Thu, 21 Dec 2023 08:00:00 +0200

How the EMV specification prevents contactless cloning and tracking

Introduction to Atari 2600 Emulation

Sun, 17 Dec 2023 14:50:00 +0200

This article provides an introduction to Atari 2600 emulation, shedding light on the principles of emulation and how to create an emulator. It discusses the challenges of understanding the hardware, the legal aspects, and offers a historical overview of the Atari 2600. While it doesn’t delve into building a full emulator, it points out key components like cartridges and opcodes. The article highlights the Atari 2600 as a suitable candidate for emulation due to its simpler technology and available documentation.

Introduction to ROS2 Humble and Gazebo Fortress

Sun, 17 Dec 2023 14:40:00 +0200

A small tutorial to apprehend more easily robot simulation with ROS2 and Gazebo

Python scripting in GDB: a CTF example

Sat, 16 Dec 2023 16:15:00 +0200

a CTF writeup that uses a GDB Python wrapper allowing scripting in GDB debugging

Fonctionnement d'un VCO (Voltage Control Oscilator)

Sat, 16 Dec 2023 16:05:00 +0200

Introduction simplifiée au design d’un VCO

How the Nintendo Switch booting process was hacked

Mon, 11 Dec 2023 08:15:38 +0200

Introduction to the Nintendo Switch booting process and how it was hacked using a buffer overflow in the recovery mode.

The miniaturisation of electronics applied to sensors

Thu, 07 Dec 2023 19:20:00 +0200

The miniaturisation of electronics applied to sensors

ReRAM, ou le futur de la mémoire depuis 1970

Thu, 07 Dec 2023 19:00:00 +0200

La Resistive Random Access Memory est une technologie de mémoire non-volatile se basant sur le phénomène de résistance. Plus compact et beaucoup moins énergivore que les autres mémoires concurrentes, elle est une très bonne candidate pour le futur des objets connectés.

Create your first application on the Flipper Zero

Fri, 24 Nov 2023 15:15:00 +0200

Introduction to the development of applications on the Flipper Zero.

Initiation to creating a Robot Arm with Raspberry Pi and Dynamixel motors

Fri, 24 Nov 2023 14:56:00 +0200

This tutorial provide guidance on building and programming an articulated robotic arm using a Raspberry Pi single board computer and Dynamixel smart servo motors. It covers the hardware components, software installation, and Python code needed to precisely control the arm’s joint positions.

Quels sont les avantages d'une architecture RISC-V comparée à une architecture ARM

Sun, 19 Nov 2023 14:30:00 +0100

Présentation des architectures RISC-V et ARM puis comparaison des deux architectures

Anatomy of an Arduino UNO

Tue, 14 Nov 2023 00:00:00 +0000

What constitutes an Arduino UNO? In this article, we will explore the electronic components of this famous board. Then, an overview about I2C and Arduino memory will be given.

Introduction to testing ESP32 code with Pytest

Thu, 19 Oct 2023 13:18:00 +0100

How to test your ESP32 code with Pytest

Mode d'endormissement de l'ESP32

Tue, 10 Oct 2023 10:42:20 +0200

Dans cet article, je vais vous introduire les différents modes d’endormissement de l’ESP32. Des exemple de code vous permettront de testé et de prendre en main ces différents mode facilement.

Overview of the Language Server Protocol

Sat, 30 Sep 2023 15:54:09 +0100

Principles of the protocol, together with examples of interactions between a client and a server.

Comment détecter une couleur avec Arduino ?

Mon, 25 Sep 2023 16:46:34 +0200

Utilisation de capteurs de couleur et d’une IA pour détecter efficacement une couleur avec une carte Arduino.

Introduction to embedded Rust

Thu, 07 Sep 2023 00:21:13 +0200

How can Rust be leveraged to make better connected toasters

Pertinence du développement système avec Hare

Sat, 01 Jul 2023 13:18:00 +0100

Comparatif entre le C et le Hare

ART of UARTS part 1

Mon, 08 May 2023 17:32:20 +0200

Electrical devices are a social species. They shout, declare, tell, utter, verbalize, yakety-yak and yak all day - all night - their blabber to one another as part of a complex herd full of protocols and social hierarchy and all that, with not much of single sound. Now, imagine a world where all those devices where to fell silent overnight ; how would you recreate communication between them ?

La conception électronique démystifiée

Tue, 28 Mar 2023 19:19:00 +0200

Une introduction rapide à la conception électronique, avec KiCad comme exemple

About DNA Data Storage

Tue, 28 Mar 2023 08:51:30 +0100

DNA data storage is an appealing alternative to mainstream information storage thanks to its density and durability. In this article, we will review the process of writing, storing and reading back DNA-coded data.

Why you need clean architecture

Tue, 28 Mar 2023 08:50:35 +0100

Introduction of clean architecture : a versatile design approach to build software.

Many processes: A VHDL state machine pattern

Mon, 13 Mar 2023 04:32:20 +0200

Introducing multi-process FSM in VHDL

Le virus Stuxnet: origine et impact

Sat, 04 Feb 2023 17:07:17 +0200

Introduction à Stuxnet

Address Sanitizer Internals

Wed, 01 Feb 2023 12:07:47 +0200

Going in depth into the Address Sanitizer internals.

Ce qui se cache sous pthread dans Linux

Wed, 11 Jan 2023 10:29:24 +0100

Comment fonctionne pthread de la glibc sous Linux.

Exotic Microcontrollers: Parallax Propeller P8X32A

Sun, 30 Oct 2022 16:07:17 +0200

Introduction of the Parallax Propeller 1 (P8X32A), a not well known micro-controller featuring 8 symetric cores.

About

Sun, 23 Oct 2022 14:39:46 +0200

GISTRE’s Blog This blog was designed as a place to share thoughts and ideas about technology, programming, and other topics that any student of GISTRE might find interesting. About GISTRE The GISTRE Major at EPITA is focused on the knowledge of systems and software platforms applied to embedded and real time projects. More info here.

Contact

Sun, 23 Oct 2022 14:39:46 +0200

Contact information You can ask any questions about this blog by sending an email to: the person in charge of the Major Geoffrey Le Gourriérec. the current blog maintainers M. Medaglia Historical main contributors of this blog 2024 Blog maintainers M. Floissac – Duforez L. Benito 2023 Blog maintainers B. Malhomme - Blog maintainer / Hugo initial deployement / Contributing guide / Modified theme A. Petit - Feedbacks / Repository / CRI Tickets P.-E. Patry - Feedbacks L. Gasnault - Blog maintainer / Building Tools / CI / Blog Content

Suckless software, or how to revive your computer

Mon, 01 Jan 0001 00:00:00 +0000

An overview of the suckless philosophy and its implementations