Bring up a Raspberry Pi 4B

Where this stands

SpaceOS does not run on the Raspberry Pi 4B today. No target profile ships for it, and the platform source lists the board under “Not currently supported” in its support matrix (docs/support-matrix.md).

The board was demonstrated under the OSIP T1 programme at the minimal integration level. That is programme history, and it is not reproducible from the platform source, which names no Pi 4B board anywhere.

Use the Raspberry Pi CM5 instead if you want a supported board on your desk today. It ships two profiles and it is the deploy reference.

The Raspberry Pi 4B is the lowest-cost board in the target matrix, intended as a daemon install: Raspberry Pi OS would keep the boot path, with the SpaceOS runner as a service on top and unikernel workloads under Solo5/KVM. The Raspberry Pi CM5 runs the system-image model (SpaceOS-owned boot, verified root, health-gated system releases); the two boards share the aarch64 architecture and the same runtime binaries.

Hardware topology

• BCM2711 SoC: quad-core ARM Cortex-A72 at 1.5 GHz.
• 2 GB / 4 GB / 8 GB LPDDR4 variants. 4 GB or more is comfortable for development.
• microSD card boot. USB-3 mass storage is faster once you configure the bootloader.
• HDMI, Ethernet, Wi-Fi, Bluetooth on the development board.

Set up the host

1. Flash a standard Raspberry Pi OS Lite (64-bit) image with rpi-imager or dd.
2. Boot the Pi and finish first-run setup.
3. Confirm KVM is available. The standard 64-bit kernel includes it; the 32-bit kernel does not.

ls /dev/kvm
lsmod | grep kvm

Steps 4 and 5 would install the SpaceOS runtime binaries and connect the board to your context as a target. Neither is possible today.

space target connect binds a board to an exact target profile, and the shipped catalog holds five: cm5, cm5-dev, hosted-linux, macos-vmm and scaleway. None of them names the Pi 4B, and the command refuses a profile it cannot resolve, so there is no working form of it for this board. Connecting a Pi 4B needs a Pi 4B profile written first.

The intended arrangement, once that profile exists, runs unikernel workloads under the Solo5 hvt tender where KVM is present, giving each one a hardware-isolated micro-VM, and falls back to the seccomp-confined spt tender where it is absent. Note that no shipped profile declares spt today, and no end-to-end test boots a workload under either tender.

Selection criteria

• Development. The board runs SpaceOS workloads against the Solo5/KVM substrate on hardware you keep at your desk.
• Ground-test bench. Pair several Pis to model a multi-machine deployment. UART-link two of them to model a bus and payload split across two machines.
• Education and hackathons. Commodity hardware is the constraint in student competitions, and the Pi 4B is the cheapest way in. Parsimoni’s adversarial testing at HACKSAT’25 is recorded as external security evidence. It does not make the Pi 4B a supported configuration.

The Pi 4B is a development board without verified boot. The Raspberry Pi CM5 is the deploy reference with verified boot and the one supported board of the three, while the Innoflight CFC-400 is a commercial flight-computer family that bring-up has not started on.