Lupos - An Operating System made in Rust with AI

Lupos is a Rust reimplementation of the Linux kernel ABI for x86_64 first, with AArch64 planned later. The success condition is binary-level Linux ABI parity: binaries built for Linux should observe Linux-compatible syscalls, filesystems, device interfaces, and process behavior.

Working on virtualbox

The public build surface is intentionally small:

• make kernel / cargo xtask build: build the pure Lupos kernel, ELF and bzImage, from the shared generic x86_64 config.
• make image / cargo xtask build --userland --iso: build the same kernel, stage a minimal Arch base userland, and emit a bootable ISO.

Both commands use configs/lupos_defconfig, which tracks the overlapping symbols from Linux's vendor/linux/arch/x86/configs/x86_64_defconfig.

Userland

The default userland is a real Arch base rootfs:

• LUPOS_DISTRO=arch
• staged guest rootfs: target/userland/stage
• root login: root / lupos
• ping smoke host: LUPOS_PING_HOST=example.com

The userland builder downloads the pinned Arch bootstrap tarball, extracts it unprivileged into target/userland/, and applies the Lupos guest overlay. No root, no chroot, no mounts required.

Prerequisites

Use a native Linux shell. Install the equivalent of these packages with your system package manager:

build-essential nasm grub-pc-bin xorriso mtools curl ca-certificates qemu-system-x86

The ISO build uses GRUB and xorriso. grub-pc-bin is required; without it grub-mkrescue builds an EFI-only ISO that QEMU's BIOS cannot boot. QEMU is required for run and smoke targets.

The X11 graphics profile (cargo xtask run --gui, LUPOS_USERLAND_GRAPHICS=1) additionally needs mkfontdir on the host, from xorg-mkfontscale (Arch) or xfonts-utils (Debian/Ubuntu), to build the core-X fonts.dir index that the pinned Arch font package ships without.

Populate vendor/linux once so the Makefile can build Linux's Kconfig tools:

./vendor/setup_linux.sh

Install the Rust toolchain components:

rustup toolchain install nightly
rustup component add llvm-tools-preview rust-src --toolchain nightly

Build

Configure once, then use one of the two canonical build commands:

make config
make kernel
make image

Equivalent xtask commands:

cargo xtask build
cargo xtask build --userland --iso

Backend build products remain available for focused work:

cargo xtask build --modules
cargo xtask build --modules-install
cargo xtask build --all

To refresh the Arch userland:

LUPOS_ARCH_REFRESH=1 cargo xtask build --userland --iso

Run

Boot in dev mode with a visible QEMU display:

cargo xtask run

Log in as root with password lupos. QEMU exposes framebuffer/DRM video, 8250 serial, virtio-net user networking, xHCI USB, and Intel HDA audio. The GUI boot uses the emulated PS/2 mouse so XFCE receives relative pointer input; other run modes retain the USB tablet. The generic config enables the matching Kconfig symbols.

Use the explicit public boot modes when you want a terminal or graphical shell:

cargo xtask run --terminal
cargo xtask run --gui        # or: make run-gui

--gui boots the X11 graphics image and opens a QEMU window on a branded LightDM GTK graphical login (Xorg on the framebuffer via xf86-video-fbdev). Log in as root / lupos at the greeter to enter the XFCE desktop, including its window manager, settings daemon, panel, desktop, file manager, and terminal. The first run stages the graphics userland automatically (LUPOS_USERLAND_GRAPHICS=1: xorg-server, xf86-video-fbdev, xf86-input-evdev, lightdm, lightdm-gtk-greeter, and the XFCE components), so it takes longer than the text login. A serial console stays available for debugging; the run prints its log path.

For QEMU/GDB debugging:

cargo xtask run --terminal --gdb
cargo xtask run --gui --gdb

For automated/headless runs, use the same command with flags:

cargo xtask run --headless
cargo xtask run --mode module-loader
cargo xtask run --ping-smoke

--ping-smoke boots Lupos with a static PID 1, exercises the guest DNS and ICMP socket paths, and emits:

ping -c 1 example.com

Override the host with:

LUPOS_PING_HOST=example.org cargo xtask run --ping-smoke

Test

cargo xtask test

The default test command runs formatting, both Rust unit suites, the driver-binary-only policy scan, the core layout/parity audits, and the critical-runtime stub gate. Deeper gates are flags:

cargo xtask test --boot
cargo xtask test --mode module-loader
cargo xtask test --mode userspace-smoke
cargo xtask test --mode runtime-stress
cargo xtask test --modules
cargo xtask test --all

Linux compliance is proven by original Linux tests cross-built and run against Lupos, through the suite build/run/compare flow in cargo xtask.

FAQ

Please check FAQ.md. If your question is not there, open an issue.