What it is #
Falcon OS is a small Linux for 64-bit Raspberry Pi boards, built from source with Buildroot. It does very little, on purpose: it boots, joins your Wi-Fi or Ethernet, appears on the local network as <name>.local, and accepts SSH. There is no desktop, no telemetry and no Falcon model on the image; it is a clean, fast base to build on.
Inside: Linux 6.12 from the Raspberry Pi kernel tree, glibc, BusyBox, OpenSSH, sudo, wpa_supplicant with the Raspberry Pi Wi-Fi firmware, dhcpcd, Avahi for .local names and the time zone database. It runs in about 1 MB of memory for its own services, so it suits the Raspberry Pi Zero 2 W and its 512 MB. On first boot it creates its own SSH host keys and grows to fill the card.
Falcon Imager is a small desktop app for macOS and Windows. Pick the image, pick the card, fill in the settings, and it writes the card and checks every byte it wrote.
Download #
Falcon Imager 0.1.0 downloads the right image for you.
| Download | For | Size |
|---|---|---|
| falcon-imager-0.1.0-macos-universal.dmg | macOS 11 or later, Apple silicon and Intel | 5.7 MB |
| falcon-imager-0.1.0-windows-x64-setup.exe | Windows 10 and 11, 64-bit | 2.4 MB |
Checksums: SHA256SUMS. Falcon Imager is MIT-licensed; the open-source licences of the libraries it is built with ship inside the app and are also listed here.
Opening the app the first time #
The apps are not signed yet, so each system warns once.
- macOS: open the disk image and drag Falcon Imager to Applications. The first time, macOS says it cannot check the app: open System Settings → Privacy & Security, find the message about Falcon Imager and choose Open Anyway. On macOS 14 and earlier you can instead Control-click the app and choose Open.
- Windows: SmartScreen says “Windows protected your PC”. Choose More info, then Run anyway. Writing a card asks for administrator approval each time.
Images #
Use these with Falcon Imager’s “Use a local file” option, or with any other SD card writer.
| Image | Boards | Download | Size |
|---|---|---|---|
| Falcon OS 2026.10.0 | Raspberry Pi 3 (64-bit), Zero 2 W, 4, 400, CM4 | falcon-os-2026.10.0-pi.img.xz (sha256) | 39 MB |
| Falcon OS 2026.10.0 | Raspberry Pi 5, 500, CM5 | falcon-os-2026.10.0-pi5.img.xz (sha256) | 38 MB |
Each image needs an SD card of 1 GB or more. The release list is what Falcon Imager reads.
Set up a card #
- Open Falcon Imager and choose Falcon OS for your board.
- Choose the SD card. Only removable cards are listed, never your computer’s own disk.
- Fill in the settings: a name for the Pi, a user and password, SSH, your Wi-Fi networks and country, and your time zone. Falcon Imager can remember them for next time.
- Write the card, put it in the Pi and power it on. After a minute or two, connect with
ssh <user>@<name>.local.
To change the Wi-Fi or the password later, put the card back in your computer and choose Change settings on an existing card; the Pi applies the change on its next boot.
How your settings are kept #
Falcon Imager writes a short settings file to the card’s boot partition. Your Wi-Fi passphrase and your password never go on the card: it holds a one-way hash of the password and the Wi-Fi key derived from the passphrase. On boot the Pi checks every value, applies them all or none, and then overwrites the file with zeros and deletes it.
If you ask Falcon Imager to remember your settings, the hash and the Wi-Fi keys go only to your computer’s own keychain (the macOS Keychain or the Windows Credential Manager), never to a plain file, and you can delete them from the app.
A card with no settings has no network login at all. On a screen and keyboard, root logs in once without a password and must choose one at that first login.
Status #
This is the first release. Falcon OS is tested on every build with about 820 checks of the settings handling, five boots in an emulated Raspberry Pi-class machine, and checks of both images. It has not yet been tested on every board, so treat this release as early: keep anything important backed up, and expect fixes in the next releases.
WPA3-only Wi-Fi networks are not supported yet.
Licences and source #
Falcon OS is made of open-source packages under their own licences (the Linux kernel and BusyBox under GPL-2.0, glibc under LGPL, and others) plus the Raspberry Pi firmware under its redistribution licence. The licence texts and the complete source of every package under a copyleft licence, exactly as built, are in falcon-os-2026.10.0-legal-info.tar (417 MB, sha256). Our own scripts and Falcon Imager are MIT-licensed.