PPCVM

Portable PowerPC virtual machine and machine emulator by Ploos AS.

Status: Experimental PowerPC32/Pegasos II emulator. Cross-assembled PowerPC ELF diagnostics execute inside PPCVM in CI; no guest operating system boots yet. Firmware, Linux handoff, MMU, and full G4 compatibility remain incomplete.

Goals

• P0: MorphOS, AmigaOS 4.x, AROS PPC.
• P1: Linux PowerPC, OpenBSD/macppc, NetBSD/ofppc and macppc.
• First machine: Pegasos II (G4 / Marvell Discovery II), followed by Sam460ex, Sam460cr, compatible Power Mac, and later AmigaOne, Efika, Genesi ODW and Mirari T1042.
• Operating modes: desktop, headless/CI, and appliance (host Linux hidden).
• Faithful emulation first; optional JIT acceleration later.

The project now includes a growing 32-bit PowerPC interpreter, a provisional Pegasos II machine model, PCI/Discovery II diagnostics, and experimental firmware/boot interfaces. These are development scaffolds, not validated Pegasos II hardware or Open Firmware compatibility.

CI evidence: build-test and windows-build-test exercise host builds/tests; powerpc-guest-execution cross-builds PowerPC ELF programs and runs guest diagnostics under PPCVM. None of these jobs currently demonstrates a Linux, MorphOS, or AmigaOS 4 boot. See roadmap for the reset-to-firmware and Linux-handoff priorities.

Build and test

cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug
cmake --build build
ctest --test-dir build --output-on-failure
./build/ppcvm --elf path/to/powerpc-be-elf32.elf --ram 128 --steps 10000 --trace --trace-limit 200 --dump-registers

First Linux/PPC boot investigation

PPCVM currently accepts ELF32 big-endian PowerPC executables, not arbitrary compressed vmlinuz, zImage, uImage, or a complete Linux installation. Use readelf -h -l kernel.elf to check the file before loading it. The interpreter must not be mistaken for a real Pegasos II firmware environment.

A first diagnostic attempt with a suitable uncompressed, ELF32 PowerPC kernel image is:

readelf -h -l kernel.elf
./build/ppcvm --elf kernel.elf --ram 256 --steps 100000 \
  --trace --trace-limit 200 --dump-registers

A successful ELF load is not evidence that Linux booted. Linux/PPC expects a board-specific firmware handoff (including a device tree or Open Firmware services, depending on kernel and platform), correct physical memory layout, exception behavior, interrupt controller and devices. PPCVM's --abi-v2 uses its private PVC1 diagnostic record and must not be passed as a Linux boot ABI. The initial goal is to record the first unsupported instruction, memory fault or missing firmware dependency and implement that prerequisite, not to declare boot success after a step limit.

Documentation

See architecture, roadmap and legal notes.