Unix-like kernel (GPL-3.0) — x86-64 bring-up under QEMU, narrow facades, partial Linux ABI.
IR0 is a operating-system kernel (GPL-3.0). Primary bring-up target is
x86-64 under QEMU (Multiboot, GRUB, VFS/MINIX, ELF userspace). Version
string: 0.0.1-rc6 (last pre-release before v0.0.1 final).
ISD is the official product userspace for IR0: runit PID 1, BusyBox,
login/firstboot, packages, rootfs, and the MINIX disk.img. Sources live in
the sibling repo ISD. This tree is the
kernel, UAPI export, and QEMU/boot orchestration.
| Layer | Role |
|---|---|
| IR0 (this tree) | mechanisms, drivers, UAPI, ISO |
| ISD (sibling repo) | packages, services, rootfs, disk.img |
| Product (both) | make first-boot / make run PROFILE=… |
IR0 does not inject BusyBox/runit/nano individually on the canonical path — ISD builds a finished image; IR0 boots it.
First boot: runit stage1 → account wizard (password also used for doas).
Logged-in shell: Unix hierarchy, uname -a, privilege elevation with doas.
BusyBox vi on the ISD rootfs (QEMU GTK).
BusyBox top: runit PID 1, runsvdir/runsv, ash, and idle.
Doom on IR0/Unix (PROFILE=desktop): framebuffer + input path.
Upstream X11 session on IR0 (PROFILE=desktop-console, manual startx): TinyX/Xfbdev, twm, xterm, Xaw clients. Terminal shows uname -a on kernel 0.0.1-rc6.
Desktop session with twm, xclock, xeyes, and xlogo; GNU nano editing a small C program in xterm (PROFILE=desktop).
Kernel panic on the GTK framebuffer (trigger: write to /sys/kernel/panic). Uptime, panic level, and Safe to power off or reboot.
git clone https://github.com/IRodriguez13/IR0.git
cd IR0
make check-env # host diagnostic (or: first-boot asks to install)
make first-boot PROFILE=minimal # host deps (ask) + clone ../ISD + image + ISO
make run PROFILE=minimal # QEMU GTK → getty → BusyBox ash
# Full desktop userspace (X11 stack) — terminal first, start GUI when you want:
make first-boot PROFILE=desktop-console
make run PROFILE=desktop-console # login → ash; then: startxfirst-boot asks before installing host packages (IR0_DEPS_INSTALL=ask|yes|never).
sudo is used only for that install, never for clone/build. It does not require Rust
nightly (only if you enable example drivers in menuconfig). Host needs musl-tools,
bison (yacc), git, curl, and the usual desktop ISO toolchain — see SETUP.md.
Layout:
parent/
├── IR0/
└── ISD/ # cloned automatically if missing
Kernel-only ISO (no shell): make ir0. Without /sbin/init on the ISD disk the
kernel panics at handoff — there is no in-kernel fallback shell.
make sync-mandocs # man pages → ~/.local/share/man (no sudo)
make man TOPIC=onboarding
make man TOPIC=bootFull coupling guide: Documentation/USERSPACE.md.
| Profile | Meaning | Status |
|---|---|---|
desktop / make desktop-x86_64 |
x86-64 ISO + QEMU | Supported — official first boot |
userspace |
musl / BusyBox ISO path | Experimental |
hub-rpi4 |
ARM64 RPi4 UART min | Hardware lab / UART — boots under QEMU raspi4b when present; not SD-flashable |
watch-rpi5-stub |
ARM64 RPi5 stub | Planned — compile-only (uart=none) |
make check-env PROFILE=desktop-x86_64
make run-bootlog # optional: boot log → build/hostshare/ir0-boot.log
make help-profiles
make pre-submit # local contributor gate → PRE_SUBMIT_OKFull toolchain notes: SETUP.md.
How to contribute: CONTRIBUTING.md.
Subsystem docs: Documentation/ — make man TOPIC=….
Linux ABI: partial by design — syscall coverage grows contract-by-contract
(Documentation/releases/IR0_0.0.1_ABI_BOARD.md, make linux-abi-audit).
x86-64 (default): uniprocessor kernel with RR scheduling, fork/exec/wait,
demand paging and fork COW paths exercised in-tree, VFS (MINIX root, tmpfs,
path-routed /proc//sys), console/TTY, musl/BusyBox bring-up. Networking
includes UDP/ICMP, AF_UNIX streams, and lab-grade TCP — not a full Internet
stack or production NIC story. Optional demos: BusyBox ash via runit
(make load-userspace-runit / run-fase58e-ash-gui), doomgeneric on /dev/fb0.
ARM64: early bring-up and board scaffolding (QEMU virt, RPi4 UART lab).
Not a flashable appliance and not feature-parity with x86.
Non-goals today: SMP, desktop-class userspace, or “better than Linux.” Near-term focus is open, rebuildable appliance profiles with a thin Makefile surface and actionable diagnostics.
Failure model: BUG_ON / ASSERT go straight to panicex() and halt
(no continue-in-prod path). Before the final banner you still get classified
output on serial: panic level, optional FAULT FRAME (CPU cause vs reporter),
[KTM][PANIC_SITE], stack/registers, and nested-fault tagging
(CLASSIFY NESTED_PANIC_OR_FAULT). Userspace faults log USER_FAULT_FRAME
without kernel panic. See includes/ir0/oops.h, kernel/lib/oops.c.
GNU General Public License v3.0 — see LICENSE.
Third-party trees (BusyBox, doomgeneric, …) keep their own licenses under setup/.