AmiVM

AmiVM is a high-performance 68k Amiga-compatible virtual machine.

Its goal is not to reproduce every historical Amiga chipset cycle. Instead, AmiVM takes the best lessons from projects such as ARAnyM, UAE-family emulators and modern virtual-machine design to build the fastest practical Amiga-class 68k system for operating systems and productivity workloads.

Project goal

Build the fastest practical 68k Amiga-compatible virtual machine while preserving enough Amiga compatibility to run useful Amiga operating systems and software.

AmiVM is intended for:

• AmigaOS-class 68k operating systems
• AROS/m68k
• Linux/m68k, including m68kDeb development and qualification
• NetBSD/m68k
• OpenBSD/m68k where the maintained port and machine requirements permit
• high-performance native 68k compilation, development and CI workloads
• workstation applications such as rendering, scenery generation and animation
• future workstation-style and appliance use

AmiVM is not primarily intended to replace cycle-accurate Amiga emulators for games, demos or hardware-timing validation.

Design principles

1. Performance first — avoid emulating historical bottlenecks that software does not require.
2. 68k-native guest model — the guest sees a 68k machine, not a translated non-68k ABI.
3. 040/060-class baseline — MMU and FPU are first-class requirements.
4. Dynarec/JIT first — x86-64 and AArch64 are tier-1 host architectures.
5. Large memory — do not impose historical Amiga RAM limits unless a compatibility profile requires them.
6. Paravirtual I/O — provide efficient virtual storage, networking, framebuffer, audio and host integration.
7. Compatibility as a profile — keep a separate compatibility machine for software that expects traditional Amiga hardware conventions.
8. Automation first — serial console, deterministic launch configuration, headless mode, snapshots and CI-friendly execution are part of the architecture.

Initial machine profiles

AmiVM Hyper/040

The initial reference machine.

• Motorola 68040-class guest CPU contract
• MMU and FPU
• JIT/dynamic translation where available
• large contiguous FastRAM-style memory
• linear framebuffer / RTG-style display
• paravirtual block storage
• paravirtual Ethernet
• virtual serial console
• host-backed shared filesystem
• minimal compatibility hardware required for boot and OS integration

AmiVM Compatibility

A later profile providing additional Amiga-compatible devices and conventions for AmigaOS software that cannot use the Hyper profile directly.

Current M1 machine map

• ROM/bootstrap: 0x00f00000, 1 MiB
• RAM: starts at 0x10000000, configurable with --ram-mib
• MMIO: starts at 0xff000000
• vmserial: 0xff000000
• timer: 0xff001000
• interrupt controller: 0xff002000

The M1 device registry and map are intentionally small and deterministic. They may evolve before the stable guest ABI milestone.

Planned virtual devices

• vmblock.device — high-throughput block storage
• vmnet.device — host-backed networking
• vmserial.device — console and automation channel
• vmfs — host/shared filesystem transport
• vmgfx — linear framebuffer / RTG-class graphics
• vmaudio.device — low-overhead audio path

Linux/m68k, NetBSD/m68k and OpenBSD/m68k may use native AmiVM drivers instead of AmigaOS device interfaces. AROS/m68k and AmigaOS use Amiga-compatible bindings and, where appropriate, the Compatibility profile.

Guest operating-system targets

AmiVM treats operating-system support as a first-class compatibility contract rather than an incidental side effect. The primary targets are:

• Linux/m68k — Tier 1; first kernel bring-up target and m68kDeb qualification platform.
• NetBSD/m68k — Tier 1 BSD target.
• OpenBSD/m68k — supported where the maintained m68k port and machine requirements make an AmiVM target practical.
• AROS/m68k — Tier 1 Amiga-compatible target and a key freely redistributable CI guest.
• AmigaOS 3.x — Tier 1 classic Amiga target through the Amiga-compatible bootstrap/device path.

The Hyper profile remains a clean high-performance 68k VM for operating systems able to use AmiVM-native devices. The Compatibility profile adds Amiga conventions only where required by AmigaOS-class software.

Performance workloads

AmiVM explicitly targets workloads that benefit from a 68k machine unconstrained by historical hardware performance:

• native m68k compilation with GCC/binutils/make and other native toolchains;
• full native package builds inside Linux/m68k and m68kDeb;
• AmigaOS/AROS native software builds and qualification;
• CPU/FPU-heavy classic workstation software;
• Vista and VistaPro rendering;
• Scenery Animator workloads;
• reproducible build and benchmark jobs suitable for CI.

Native compilation is a first-class performance goal: AmiVM should make it practical to build m68k software inside a real m68k guest while approaching the convenience expected from modern development infrastructure.

Relationship to existing emulators

AmiVM complements rather than replaces projects such as FS-UAE, Amiberry and FellowNG.

Those projects are valuable when accurate Amiga-machine compatibility matters. AmiVM deliberately explores the other end of the design space: an Amiga-compatible 68k virtual workstation optimized for performance, modern I/O and operating-system workloads.

ARAnyM is an important architectural reference because it demonstrates the value of a fast extended 68k virtual machine rather than strict reproduction of one historical computer. AmiVM will adopt useful ideas while defining its own machine and device contracts.

Status

M1 — VM core skeleton: complete.

The host now has configurable RAM and ROM loading, a guest physical memory map, explicit MMIO device registration, interrupt/timer baselines, vmserial, deterministic machine description and Release-safe VM-core tests.

Next: M2 — 68k execution. The next proof point is a CPU-backend abstraction followed by reset-vector and first-instruction execution for the Hyper/040 guest.

See ROADMAP.md and docs/ARCHITECTURE.md.

License

MIT. Copyright Ploos AS.