Open-source alternatives to Bootloader

This project is a freestanding kernel written in Rust that boots on x86 hardware without a standard library. It serves as a low-level system implementation focusing on the creation of a bare metal operating system. The system implements a bootable disk image toolchain that transforms source code into binaries compatible with a bootloader. It features a custom memory allocator for dynamic memory management and an x86 kernel implementation that includes paging, interrupt handling, and VGA text mode. The project covers several core capability areas, including low-level memory management through

Embedded-hal is a hardware abstraction layer for embedded microcontrollers that defines common traits allowing peripheral drivers to remain entirely independent of specific hardware platforms. The library provides platform-agnostic interfaces that decouple driver logic from microcontroller architectures, utilizing zero-cost trait abstractions that compile down to direct hardware register manipulations without runtime overhead or memory allocation. The project features asynchronous execution support and synchronous-to-asynchronous adaptation, enabling non-blocking peripheral operations and coo

m1n1 is a low-level bootloader for ARM64-based Apple Silicon hardware. It serves as a firmware tool and experimentation environment for loading external kernels and non-native operating systems. The project enables the execution of concatenated binary payloads containing kernels, device trees, and ramdisks. It provides a platform for firmware experimentation and the deployment of custom kernels on Apple Silicon chips. The system covers low-level hardware abstraction, including memory-mapped register access, device tree transmission, and stage-based bootloading. It also includes UART-based se

Atmosphere is a custom firmware for the Nintendo Switch that provides core system components for loading custom kernels, managing modified operating systems, and redirecting hardware storage. It functions as a customized operating system designed to enable deep system modification and functional extensions. The project distinguishes itself through a system module injector and an application patching engine that allow for the loading of custom binary modules and patches to add features to the console. It also includes a virtual storage manager that redirects internal hardware writes to a virtu

This project is a shell-scripted utility designed for cloning and synchronizing Linux system disks. It enables the creation of bootable copies of active storage devices, allowing users to maintain functional backups or prepare new storage media for embedded computing environments. The tool performs partition-aware cloning by analyzing the source drive structure to recreate identical layouts on destination disks. It distinguishes itself by modifying boot configuration files and partition identifiers on the target drive, which ensures that cloned media remain bootable when moved to new hardware

ToaruOS is an independent operating system built from the ground up without external dependencies. It features a custom x86-64 kernel that supports symmetric multiprocessing and paging, paired with a graphical windowing system and a dedicated bytecode interpreter for application logic. The system distinguishes itself by integrating an embedded Python environment for system-level development and a custom graphical interface that handles its own window composition and text rendering. It includes a compatibility layer for third-party application support and a system package manager for handling

microvm.nix is a declarative virtual machine manager and orchestrator for defining, building, and managing isolated guest environments using Nix. It functions as a virtual machine image builder that transforms system specifications into bootable disk images and runner scripts. The project provides a hypervisor abstraction layer, enabling the deployment of guest images across multiple virtualization backends through a unified configuration. It includes specialized tools for PCI hardware passthrough, granting virtual machines direct access to physical host USB and PCI devices. The framework co

This project is a bare-metal operating system developed for ARM64 architecture. It serves as a low-level implementation of kernel engineering, focusing on the fundamental construction of an OS from the hardware level up. The system is distinguished by its comprehensive approach to ARM64 processor control, featuring a red-black tree task scheduler and a hierarchical page table system for virtual memory management. It implements a sophisticated privilege model that handles transitions between kernel and user modes, ensuring process isolation through address space splitting and exception level m

motioneyeos is a dedicated video surveillance operating system and embedded OS build system designed to turn single-board computers into standalone network video monitoring stations. It functions as a specialized Linux-based distribution for resource-constrained hardware, providing the necessary infrastructure to manage a network of cameras for continuous security monitoring. The project features a menu-driven build automation pipeline that allows for the configuration, compilation, and validation of custom system images. It utilizes toolchain-based cross compilation to ensure compatibility a

WinDiskWriter is a specialized utility for creating bootable Windows installation media from a macOS environment. It writes operating system images to USB drives while providing support for both UEFI and Legacy BIOS boot interfaces. The tool includes a file splitter to divide installation files larger than four gigabytes, ensuring compatibility with FAT32 formatted boot drives. It also provides a hardware bypass utility that modifies Windows 11 installers to remove TPM 2.0 and Secure Boot requirements. The software manages low-level disk image writing and bootloader integration. It handles s

NodeOS is an operating system that boots a Linux kernel with Node.js running as the primary userspace, replacing traditional shell utilities with JavaScript execution. Every npm package is treated as a native system command, making hundreds of thousands of packages directly executable at the OS level. The operating system is built inside Docker containers using a reproducible pipeline that generates ext2 filesystem images, with the ability to conditionally disable KVM for systems without hardware virtualization. It mounts a persistent usersfs partition for user home directories, preserving ch

This project is an OpenWrt firmware builder and specialized Linux router distribution designed to repurpose Amlogic S9xxx series hardware into functional routers. It provides a hardware adaptation layer consisting of kernel modifications and drivers that enable the operating system to run on Amlogic ARM SoC devices. The project features an automated firmware pipeline for scheduling, building, and distributing custom images. It includes a device recovery toolkit for bootstrapping, flashing, and restoring factory images, and supports the conversion of devices previously running different mobile

fnnas is a Debian-based network attached storage operating system and deployment framework designed to transform x86 and Arm64 hardware into private storage servers. It provides a custom operating system image builder and a kernel compilation tool for building and packaging specific kernels and device tree blobs for various hardware platforms. The project includes a hardware-specific deployer that maps device models to required bootloaders and kernel tags. It features an eMMC backup and recovery tool to save factory system images from internal storage and restore them to revert system changes

30dayMakeOS is an educational hobby operating system project designed for the x86 architecture. It implements a monolithic kernel and a custom bootloader that transitions the CPU from real mode to 32-bit protected mode to enable flat memory addressing. The project focuses on low-level system development, featuring a custom graphics driver for direct pixel-buffer rendering and window management without an existing operating system. It includes an x86 bootloader that loads the kernel from disk into memory. The system covers core kernel capabilities including round-robin task scheduling for pro

LiteX is an FPGA SoC development suite and SoC builder framework used to programmatically design system-on-chips. It provides a hardware description toolchain that uses a scriptable framework to define hardware layouts and automate the generation of hardware description language code. The project distinguishes itself by orchestrating multiple vendor and open-source toolchains to synthesize digital logic and generate deployable bitstreams. It supports multi-language logic integration, allowing disparate hardware description languages to be combined into a single project. The framework covers

Brunch is a boot framework and hardware adaptation layer designed to run ChromeOS on non-native x86_64 PCs. It utilizes a custom EFI bootloader and kernel injection to enable the operating system to function on Intel and AMD processors not originally supported by official images. The framework distinguishes itself by transforming official recovery images into generic bootable versions through the use of custom kernels and EFI partition bootstrapping. It allows for the importation of security keys into system firmware to support secure boot and provides tools to toggle hardware patches and fea

Anbox is an Android container environment and runtime designed to execute Android applications on Linux desktops. It utilizes a container-based system to run the Android operating system without the overhead associated with traditional hardware virtualization. The system features a hardware abstraction layer that routes hardware access and sensor data through a host daemon to provide accelerated rendering. It integrates with the Linux desktop by mapping individual Android application layers to separate windows, allowing apps to function as distinct desktop applications. The project supports

XNU is an operating system kernel designed to manage system hardware and process execution across different processor architectures. It utilizes a hybrid microkernel design that combines microkernel message passing with monolithic kernel performance by embedding critical subsystems into a single address space. The project implements a port-based asynchronous messaging system for communication between kernel tasks and userspace processes. It manages hardware interactions through a layered driver architecture and enforces system-wide security policies via a mandatory access control interface.

Cloud Hypervisor is a Rust-based hypervisor and KVM virtual machine monitor designed to execute 64-bit guest operating systems. It functions as a user-space virtual machine manager that employs a minimal emulation layer to reduce memory overhead and latency for cloud workloads. The project distinguishes itself through the use of a memory-safe language to implement a virtio device emulator and a user-space device model. It provides a standardized web API for managing virtual machine lifecycles and resource configurations. The platform covers broad virtualization capabilities, including the em

v86 is a browser-based virtual machine and x86 hardware simulator that allows 16-bit and 32-bit operating systems to run directly within a web page. It functions as an x86 emulator for WebAssembly, simulating CPUs, memory, and storage devices to execute legacy software without original native hardware. The project utilizes a WebAssembly just-in-time compiler to translate x86 machine code into WebAssembly modules for high-performance execution in the browser. The system covers hardware emulation and lifecycle management, including the ability to boot from disk images, configure virtual hardwa

xv6-riscv is a simplified Unix-like teaching operating system designed for the study of kernel design and hardware interaction. It provides a low-level RISC-V kernel implementation that serves as a bootable system image for execution and debugging within a virtual machine or emulator. The project focuses on educational instruction regarding the RISC-V architecture. It enables the study of operating system concepts through a minimal kernel that implements process management and memory handling. The system covers core kernel operations including multiprocessor resource management and the imple

This project provides a functional package manager and a reproducible build system designed to ensure identical build inputs always produce the same outputs. It serves as the foundation for a declarative Linux distribution where the entire system state is defined in a configuration file, enabling predictable deployments and full-system rollbacks. The system uses a deterministic functional language and a lazy-evaluation expression engine to manage software dependencies and isolate build environments. It distinguishes itself through a content-addressable store that allows multiple versions of s

Microsandbox is a runtime for creating and managing lightweight, hardware-isolated virtual machines — called sandboxes — that boot directly from standard OCI container images. Each sandbox runs as its own host process with a separate kernel, filesystem, and network stack, providing process-per-sandbox isolation. The project includes a command-line tool and multi-language SDKs (Rust, TypeScript, Python, Go) for programmatic lifecycle control, and it communicates with sandbox agents over Unix sockets using a CBOR-encoded protocol. What distinguishes Microsandbox is its combination of host-manag

microsandbox is a platform that runs untrusted code inside hardware-isolated microVMs, each with its own kernel, filesystem, and network stack. It boots directly from standard OCI container images, supports copy-on-write filesystem layers, and integrates with AI agents to execute tool calls and generated code in isolated environments with secret protection. What sets microsandbox apart is its host-side network proxy that enforces firewall rules, intercepts DNS, inspects TLS traffic, and injects secrets at the network boundary without exposing them inside the VM. It provides SSH access to micr

PX4-Autopilot is a professional-grade flight control software stack designed for autonomous unmanned vehicles, including multicopters, fixed-wing aircraft, and vertical takeoff and landing platforms. It operates as a modular, real-time framework that decouples flight control logic from hardware drivers through a publish-subscribe middleware architecture. The system utilizes a deterministic microkernel runtime to execute time-critical flight control loops and sensor fusion tasks, ensuring stable navigation and vehicle operation. The platform distinguishes itself through a parameter-driven conf

This project is an educational resource for developing bare-metal operating systems and kernels from scratch on Raspberry Pi hardware. It provides a structured guide to systems programming using the Rust language, focusing on the implementation of core kernel components that execute directly on ARM-based hardware without the support of an underlying operating system or standard library. The tutorials emphasize a modular architecture that separates hardware-independent kernel logic from processor-specific and board-specific configurations. By utilizing a hardware abstraction layer and distinct

F Prime is a component-based framework designed for the development and deployment of embedded and spaceflight software. It provides a modular architecture that decouples software logic from communication interfaces, allowing developers to define system structures through a domain-specific modeling language. This model-based approach enables automated code generation, ensuring consistency across complex system topologies while maintaining strict interface contracts between software modules. The framework distinguishes itself through its integrated build system and ground data operations suite