MINIX 3

MINIX 3 is a free, open-source operating system designed to be highly reliable, flexible, and secure. Unlike traditional monolithic kernels (like Linux or Windows) where a single driver crash can bring down the entire system, MINIX 3 is built on a tiny microkernel architecture.

The project's primary goal is to create a "self-healing" system that can detect and repair its own faults on the fly without user intervention.

Note: This repository is a fork maintained by David Montero and is NOT maintained by the Stichting MINIX Research Foundation. See What's New for changes relative to upstream.

• Fault Tolerance — Most of the OS runs as isolated user-mode processes. If a driver crashes, it is automatically restarted by the Reincarnation Server without affecting the rest of the system.
• Microkernel Design — The kernel itself is only about 6,000 lines of executable code, making it easier to verify and secure.
• POSIX Compliant — Supports a wide range of standard UNIX software.
• NetBSD Compatibility — Uses the NetBSD pkgsrc package management system, giving access to thousands of prebuilt packages.
• Multi-Architecture — Runs on x86 (IA-32), x86-64 (amd64), and ARM.
• SMP Support — Symmetric multi-processing up to 32 CPUs.
• Educational Foundation — Originally created by Andrew S. Tanenbaum; a world-class resource for learning OS design and implementation.

MINIX 3 is structured in four layers:

The headline change is a new x86-64 (amd64) kernel port that boots to a login prompt under QEMU, with IDE storage, serial console, ACPI/APIC, and support for process address spaces above 2 GB. Other highlights since the upstream base:

• Modern CPU features — NX/XD enforcement, XSAVE/AVX FPU context, SSE4 / AVX2 / AES-NI / RDRAND / x2APIC / PCID detection, SMP limit raised to 32.
• New drivers — Intel I225/I226 2.5 GbE (igc), EHCI USB host (Phase 1), OHCI scaffolding (Phase 3a), multi-controller usbd.
• Security hardening — tree-wide audit replacing unsafe strcpy / sprintf / system() patterns; buffer-overflow fixes in kgets, backup, fdisk, minix-service; ELF auxvec UID/GID populated correctly.
• Performance — 30+ O(N²) strlen-in-loop patterns eliminated across the tree.
• Build & toolchain — GCC 15 compatibility, LLVM/clang by default, NetBSD 10 host-tools sync, C++ ATF and kyua-cli tests re-enabled.
• Test coverage — new ATF tests for dup2, libc string functions, the ISC event timer library, hgfs, cd9660, and PM ptrace.

For the full change log, see RELEASE_NOTES.md.

For the best experience, run MINIX 3 inside a virtual machine.

• Hypervisor: VirtualBox, VMware, or QEMU
• Image: build from source (see below) or download from the upstream Official Downloads Page

# i386 (original upstream target)
sh build.sh -j4 -mi386 -O ../obj.i386 -D ../obj.i386/destdir.i386 -U -u release
bash releasetools/x86_cdimage.sh

# amd64 (this fork)
sh build.sh -j4 -mamd64 -O ../obj.amd64 -D ../obj.amd64/destdir.amd64 -U -u release
bash releasetools/amd64_cdimage.sh

# amd64 ISO
qemu-system-x86_64 --enable-kvm -cdrom minix_amd64.iso

# amd64 HDD image
qemu-system-x86_64 --enable-kvm -m 256M -hda minix_amd64.img

1. Create a VM (256 MB RAM, 2 GB+ HDD).
2. Mount the ISO and boot.
3. Log in as root (no password).
4. Run setup and follow the prompts.
5. Power off, remove the ISO, reboot.

For detailed instructions see the MINIX 3 Installation Guide.

• Official Wiki: wiki.minix3.org
• User Guide: Getting Started
• Release Notes: RELEASE_NOTES.md — detailed changelog since the fork
• Book: Operating Systems: Design and Implementation (3rd ed.) — Tanenbaum & Woodhull

Pull requests are welcome. Whether you are fixing bugs, porting drivers, or improving documentation:

• Source tree is at /usr/src on a running MINIX system.
• Please follow existing BSD code style.
• Prefer strlcpy/strlcat over strcpy/strcat; snprintf over sprintf.
• For security-sensitive changes, reference the relevant CWE in the commit message.

MINIX 3 is released under the BSD-3-Clause License. See the LICENSE file for details.