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Milestones

ThemeliOS development is organized into phases. Each phase builds on the previous one and produces a working, testable artifact.

Phase 0 — Boot

Goal: Get the kernel booting on QEMU and printing to the serial console.

Deliverables:

  • Bootloader integration (Limine or UEFI)
  • Architecture-specific early init (x86_64 first)
  • Serial console output (16550 UART on x86_64)
  • “Hello from ThemeliOS” printed on boot
  • cargo xtask run boots the kernel in QEMU end-to-end

What you’ll learn: Bare-metal Rust, the boot process, how hardware/QEMU works at the lowest level.

Phase 1 — Kernel basics

Goal: A kernel that can manage memory and schedule tasks.

Deliverables:

  • Physical frame allocator (bitmap-based)
  • Virtual memory manager (page table setup, higher-half kernel)
  • Kernel heap allocator
  • Interrupt handling (IDT on x86_64, GIC on aarch64)
  • Timer-driven preemptive scheduler (round-robin)
  • Basic kernel shell over serial (for debugging, will be removed later)
  • aarch64 port of Phase 0 + Phase 1

Phase 2 — Isolation

Goal: Implement the capability system and process isolation.

Deliverables:

  • Capability types and capability space (CSpace)
  • Process creation with isolated address spaces
  • Capability grant, transfer, and revocation
  • Synchronous IPC (message passing between processes)
  • First userspace process (init)

Phase 3 — Storage

Goal: Read from a virtual disk and present a filesystem.

Deliverables:

  • VirtIO block driver (for QEMU’s virtual disk)
  • Read-only filesystem (simple format, possibly custom or FAT)
  • RAM-backed ephemeral writable layer
  • Immutable root image creation tooling

Phase 4 — Networking

Goal: TCP/IP connectivity.

Deliverables:

  • VirtIO network driver
  • Ethernet, ARP, IPv4
  • TCP and UDP
  • Basic socket-like API via capabilities
  • DHCP client

Phase 5 — Containers

Goal: Run OCI container images.

Deliverables:

  • OCI image format parsing and layer unpacking
  • Container lifecycle (create, start, stop, destroy)
  • Container-to-capability mapping (each container gets a capability set)
  • Container networking (virtual interfaces, isolation)
  • Log streaming from containers

Phase 6 — Management

Goal: External API for managing the node.

Deliverables:

  • HTTP or gRPC management API
  • Container management endpoints (create, start, stop, list, logs)
  • Node status and health reporting
  • Configuration injection at boot time
  • No SSH — API is the only interface

Future — Kubernetes

Goal: Serve as a K8s/K3s worker node.

Deliverables (rough):

  • CRI-compatible container runtime
  • kubelet (or custom equivalent)
  • CNI plugin support
  • Node registration with K8s control plane
  • Pod lifecycle management

This phase is explicitly not v1 and will be scoped in detail after Phase 6 is complete.