Alpenglow

General-purpose musl+LLVM Linux distribution. dinit init, Oil packages. Boots to login in <1s on native virt (x86_64 KVM or aarch64 HVF).

Two deployment modes:

• Diskless/immutable — initramfs-only, RAM root, GlowFS overlay (appliance mode)
• Rootfs — normal root-on-disk (ext4/btrfs/zfs), package-managed

scripts/boot-native.sh           # build + boot initramfs (QEMU)
system/backends/appliance/scripts/qemu.sh   # boot existing build

Platform support:

• x86_64 — main branch (primary target)
• aarch64 — arch/aarch64 branch — QEMU virt, Apple Silicon HVF
• riscv64 — arch/riscv64 branch — QEMU virt, OpenSBI
• Rockchip RK3566 — board/rk3566 branch — PINE64 Quartz64

Quick Start

# Initramfs (diskless) mode — build + boot in QEMU
./scripts/boot-native.sh

# Rootfs mode — install to disk
# I'll clean up these instructions later, and am gonna make a website or sm for this.

# Custom kernel
KERNEL_BUILD=1 ./scripts/boot-native.sh

Design

Layer	Choice	Notes
Init	dinit	Parallel dependency graph, both modes
Userland	toybox (838KB), oksh	Static musl, no glibc
Package mgr	Oil	APK-compatible, standalone binary
Kernel	Linux 7.0 + Rust modules	CONFIG_RUST=y, alpenglow_core.ko
Kernel ctrl	kernelctl (Zig, 89KB)	Static, µs-scale startup
Network	netd (Rust), udhcpc, iwd	Zero-external-deps netd
Root FS	Diskless: GlowFS/erofs/squashfs in RAM. Rootfs: ext4 over LUKS
Compositor	Wayland + cage + foot	Optional, not in base
Security	AppArmor, read-only root (optional)	Hardened by default
Audio	ALSA + PipeWire
Kernel	Linux 7.0+ with CONFIG_RUST=y, GlowFS in-tree

Project Layout

system/
  backends/
    appliance/          Primary profile (kernel configs, dinit services, scripts)
  kernelctl-zig/        Cgroup + kernel policy (Zig, 89KB static)
  netd/                 Network state daemon (Rust, zero deps)
  glowfsctl-zig/        GlowFS image tooling (Zig, 164KB)
  oil/                  Package manager (Rust, APK-compatible)
  glowfs/               GlowFS kernel module source (C+Rust)
  kernel-modules/       Rust kernel modules (alpenglow_core, alpenglow_bootstat)
  init/                 Zig init (4.8KB static, initramfs fallback)
scripts/                Build, CI, benchmark scripts
docs/                   Architecture, build, install docs

Kernel configs live at system/backends/appliance/kernel/.

Performance

Boot to login (QEMU KVM, quiet)

OS	Boot	Initramfs	Kernel	Idle RAM
Alpenglow min	0.6s	1.4K	4.4MB	~17MB
Alpenglow std	1.3s	1.7MB	4.4MB	~26MB
Alpine Linux virt	1.3s	8.7MB	6.5MB	~58MB
Void Linux	2.5s	12MB	7MB	~80MB
Ubuntu Server	15s	40MB	12MB	~200MB

Alpenglow minimal (Zig init, 4.8KB) boots in 0.6s on x86_64 KVM. The standard build (dinit + toybox + getty) is 1.3s. Alpine matches boot speed but has 6000x larger initramfs and 3x the RAM. Both modes use the same toolchain — the difference is just initramfs contents.

Binary size (static musl, x86_64)

Tool	Lang	Size	vs alternative
kernelctl	Zig	89KB	501KB (Rust)
glowfsctl	Zig	164KB	501KB (Rust)
init	Zig	4.8KB	937KB (toybox+sh)
dinit	C++	1.6MB	20MB+ (systemd)
toybox	C	838KB	10MB+ (coreutils)
alpenglow_core.ko	Rust	9.2K	kernel built-in

Modes

Alpenglow runs in two deployment modes sharing the same codebase:

Diskless/Appliance — boot from initramfs, root in RAM (tmpfs), state on persistent partition. Uses GlowFS squashfs for verified immutable root. Target: embedded, edge, kiosk, containers.

Rootfs/Desktop — install to disk (ext4 over LUKS), normal r/w root. dinit manages services, Oil installs packages. Target: workstation, server, development.

The init script auto-detects mode: if /dev/disk/by-label/alpenglow-root exists, it switches root; otherwise runs diskless. Both modes use the same kernel, toolchain, and package format.

Services

Service	Status	Appliance	Desktop	Managed by
SSH (dropbear)	✅	✅	✅	dinit
NTP (chronyd)	✅	✅	✅	dinit
DNS cache (dnsmasq)	✅	✅	✅	dinit
Logging (syslogd)	✅	✅	✅	dinit
DHCP networking	✅	✅	✅	dinit
WiFi (iwd)	✅	optional	✅	dinit
Wayland + sway	✅	optional	✅	dinit
Audio (PipeWire)	✅	optional	✅	dinit
Package manager (Oil)	✅	✅	✅	dinit
Kernel policy (kernelctl)	✅	✅	✅	dinit
GlowFS mount	✅	✅	optional	dinit

Status

It boots on real hardware! 22/22 milestones. Booted on 2012 Mac Mini.

See AGENTS.md for full milestone table and docs/ for architecture docs.