SkiffOS is a lightweight operating system for any Linux-compatible computer, ranging from RPi, Odroid, NVIDIA Jetson, to Desktop PCs, Laptops (i.e. Apple MacBook), Phones, Cloud VMs, and even Web Browsers. It is:
- Familiar: uses simple Makefile and KConfig language for configuration.
- Flexible: supports any OS distribution inside containers w/ ssh drop-in.
- Portable: replicate the exact same system across any hardware or arch.
- Reliable: read-only minimal in-RAM host system boots reliably every time.
- Reproducible: offline and deterministic builds for reproducible behavior.
SkiffOS adds a configuration package system to the Buildroot cross-compiler,
which makes it easy to re-target applications to new hardware. Packages are
merged together as specified in the SKIFF_CONFIG comma-separated environment
variable. For example: SKIFF_CONFIG=pi/4,core/gentoo will run Gentoo on a
Raspberry Pi 4.
Most Linux devices have a unique set of requirements for kernel, firmware, and hardware support packages. The SkiffOS host OS separates hardware-specific support from the containerized user environments, simplifying management of updates across multiple hardware combinations.
Buildroot dependencies must be installed as a prerequisite.
This example uses pi/4 for the Raspberry Pi 4, see Supported Systems.
Create a SSH key on your development machine. Add the public key to your build
with cp ~/.ssh/*.pub ./overrides/root_overlay/etc/skiff/authorized_keys. This
will be needed to enable SSH access.
$ make # lists all available options
$ export SKIFF_WORKSPACE=default # optional: supports multiple SKIFF_CONFIG at once
$ export SKIFF_CONFIG=pi/4,skiff/core
$ make configure # configure the system
$ make compile # build the systemAfter you run make configure your SKIFF_CONFIG selection will be saved. The
build can be interrupted and later resumed with make compile.
SKIFF_WORKSPACE defaults to default and is used to compile multiple
SKIFF_CONFIG simultaneously.
There are many other utility commands made available by Buildroot, which can be
listed using make br/help, some examples:
$ make br/menuconfig # explore Buildroot config menu
$ make br/sdk # build relocatable SDK for target
$ make br/graph-size # graph the target packages sizesThere are other application packages available i.e. apps/podman.
Once the build is complete, it's time to flash the system to a SD card. You will
need to switch to sudo bash for this on most systems.
$ sudo bash # switch to root
$ blkid # look for your SD card's device file
$ export PI_SD=/dev/sdz # make sure this is right!
$ make cmd/pi/common/format # tell skiff to format the device
$ make cmd/pi/common/install # tell skiff to install the osThe device needs to be formatted only one time, after which, the install command can be used to update the SkiffOS images without clearing the persistent data. The persist partition is not touched in this step, so anything you save there, including all Docker containers and system configuration, will not be modified.
Connect using SSH to root@my-ip-address to access the SkiffOS system, and
connect to core@my-ip-address to access the "Core" system container. See the
section above about SSH public keys if you get a password prompt.
The mapping between users and containers can be edited in the
/mnt/persist/skiff/core/config.yaml file.
The system can then be upgraded over-the-air (OTA) using the rsync script:
$ ./scripts/push_image.bash root@my-ip-addressThe SkiffOS upgrade (or downgrade) will take effect on next reboot.
Use the apps/podman configuration package to enable Podman support.
SkiffOS is based on Buildroot, which can compile operating systems for any Linux-compatible machine.
Here are the boards/systems currently supported:
| Board | Config Package | Bootloader | Kernel | Notes |
|---|---|---|---|---|
| VirtualBox | virt/virtualbox | N/A | ✔ 5.19.14 | Run in VM |
| Docker Img | virt/docker | N/A | N/A | Run in Docker |
| Qemu | virt/qemu | N/A | ✔ 5.19.14 | Run in QEmu |
| V86 on WebAssembly | browser/v86 | V86 | ✔ 5.19.14 | Run in Browser |
| WSL on Windows | virt/wsl | N/A | N/A | Run in WSL2 |
| ----------------------- | ----------------------- | ------------------ | ----------------- | ------------------ |
| Allwinner Nezha | allwinner/nezha | ✔ U-boot 2022.07 | ✔ sm-5.19-rc1 | RISC-V D1 |
| Apple Macbook | apple/macbook | ✔ rEFInd | ✔ 5.19.14 | ✔ Tested |
| BananaPi M1+/Pro | bananapi/m1plus | ✔ U-Boot 2022.04 | ✔ 5.19.14 | ⚠ Obsolete |
| BananaPi M1 | bananapi/m1 | ✔ U-Boot 2022.04 | ✔ 5.19.14 | ⚠ Obsolete |
| BananaPi M2+ | bananapi/m2plus | ✔ U-Boot 2022.04 | ✔ 5.19.14 | |
| BananaPi M2 | bananapi/m2 | ✔ U-Boot 2022.04 | ✔ 5.19.14 | ⚠ Obsolete |
| BananaPi M3 | bananapi/m3 | ✔ U-Boot 2022.04 | ✔ 5.19.14 | ✔ Tested |
| BeagleBoard X15 | beaglebone/x15 | ✔ U-Boot 2022.04 | ✔ 5.10.109-ti | |
| BeagleBone AI | beaglebone/ai | ✔ U-Boot 2022.04 | ✔ 5.10.109-ti | |
| BeagleBone Black | beaglebone/black | ✔ U-Boot 2022.04 | ✔ 5.10.109-ti | |
| BeagleBoard BeagleV | starfive/visionfive | ✔ U-Boot 2021.04 | ✔ sv-5.19-rc3 | RISC-V |
| Intel x86/64 | intel/desktop | ✔ rEFInd | ✔ 5.19.14 | ✔ Tested |
| ModalAI Voxl2 | modalai/voxl2 | N/A | ✔ msm-4.19.125 | |
| NVIDIA Jetson AGX | jetson/agx | ✔ UEFI | ✔ nv-5.10.104 | ✔ Tested |
| NVIDIA Jetson Nano | jetson/nano | ✔ U-Boot | ✔ nv-4.9.309 | ⚠ Obsolete |
| NVIDIA Jetson TX2 | jetson/tx2 | ✔ U-Boot | ✔ nv-4.9.309 | ⚠ Obsolete |
| Odroid C2 | odroid/c2 | ✔ U-Boot 2022.07 | ✔ tb-5.18.12 | ⚠ Obsolete |
| Odroid C4 | odroid/c4 | ✔ U-Boot 2022.07 | ✔ tb-5.18.12 | |
| Odroid HC1 | odroid/xu | ✔ U-Boot 2017.07 | ✔ tb-5.18.12 | ⚠ Obsolete |
| Odroid HC2 | odroid/xu | ✔ U-Boot 2017.07 | ✔ tb-5.18.12 | ✔ Tested |
| Odroid HC4 | odroid/hc4 | ✔ U-Boot 2022.07 | ✔ tb-5.18.12 | |
| Odroid M1 | odroid/m1 | ✔ U-Boot 2017.09 | ✔ tb-5.18.12 | |
| Odroid N2+ | odroid/n2 | ✔ U-Boot 2022.07 | ✔ tb-5.18.12 | ✔ Tested |
| Odroid U | odroid/u | ✔ U-Boot 2022.07 | ✔ tb-5.18.12 | ⚠ Obsolete |
| Odroid XU3 | odroid/xu | ✔ U-Boot 2017.07 | ✔ tb-5.18.12 | ⚠ Obsolete |
| Odroid XU4 | odroid/xu | ✔ U-Boot 2017.07 | ✔ tb-5.18.12 | ✔ Tested |
| OrangePi Lite | orangepi/lite | ✔ U-Boot 2018.05 | ✔ 5.19.14 | |
| OrangePi Zero | orangepi/zero | ✔ U-Boot 2018.07 | ✔ 5.19.14 | |
| PcDuino 3 | pcduino/3 | ✔ U-Boot 2019.07 | ✔ 5.19.14 | |
| PcEngines APU2 | pcengines/apu2 | ✔ CoreBoot | ✔ 5.19.14 | |
| Pi 0 | pi/0 | N/A | ✔ rpi-5.15.72 | ✔ Tested |
| Pi 1 | pi/1 | N/A | ✔ rpi-5.15.72 | |
| Pi 3 + 1, 2 | pi/3 | N/A | ✔ rpi-5.15.72 | ✔ Tested |
| Pi 4 | pi/4 | N/A | ✔ rpi-5.15.72 | ✔ Tested |
| Pi 4 (32bit mode) | pi/4x32 | N/A | ✔ rpi-5.15.72 | ✔ Tested |
| Pine64 H64 | pine64/h64 | ✔ U-Boot 2022.04 | ✔ megi-6.0 | |
| PineBook A64 | pine64/book_a64 | ✔ U-Boot (bin) | ✔ megi-6.0 | ⚠ Obsolete |
| PineBook Pro | pine64/book | ✔ U-Boot (bin) | ✔ megi-6.0 | ✔ Tested |
| PinePhone | pine64/phone | ✔ U-Boot (bin) | ✔ megi-6.0 | ✔ Tested |
| Rock64 rk3328 | pine64/rock64 | ✔ U-Boot 2022.04 | ✔ megi-6.0 | ✔ Tested |
| RockPro64 | pine64/rockpro64 | ✔ U-Boot (bin) | ✔ megi-6.0 | ✔ Tested |
| Sipeed LicheeRV | allwinner/licheerv | ✔ U-Boot 2022.07 | ✔ sm-5.19-rc1 | RISC-V D1 |
| StarFive VisionFive | starfive/visionfive | ✔ U-Boot 2021.04 | ✔ sv-5.19-rc3 | RISC-V |
| USBArmory Mk2 | usbarmory/mk2 | ✔ U-Boot 2020.10 | ✔ 5.19.14 | ✔ Tested |
| Valve Steam Deck | valve/deck | N/A | ✔ valve-5.13.0 | |
| Wandboard | freescale/wandboard | ✔ U-Boot 2022.04 | ✔ 5.19.14 |
All targets marked "tested" use automated end-to-end testing on real hardware. Targets marked "Obsolete" are discontinued by their manufacturer but still have a corresponding SkiffOS configuration and should still work.
Adding support for a board involves creating a Skiff configuration package for the board, as described above. If you have a device that is not yet supported by SkiffOS, please open an issue.
SkiffOS Core runs Linux distributions in privileged containers:
- YAML configuration for mapping users to containers
- systemd and/or other init systems operate as PID 1 inside the container
- container images can be pulled or compiled from scratch
Adding skiff/core to SKIFF_CONFIG enables Debian Sid with an XFCE desktop.
Other distributions and images supported:
| Distribution | Config Package | Notes |
|---|---|---|
| Alpine | core/alpine | OpenRC |
| Debian Sid | skiff/core | Default: XFCE desktop |
| Fedora | core/fedora | Minimal desktop |
| Gentoo | core/gentoo | Based on latest stage3 |
| Ubuntu | core/ubuntu | Snaps & Ubuntu Desktop |
Other less frequently updated images:
| Distribution | Config Package | Notes |
|---|---|---|
| DietPi | core/dietpi | DietPi applications tool |
| NASA cFS Framework | core/nasa_cfs | Flight software framework |
| NASA Fprime Framework | core/nasa_fprime | Flight software framework |
| NixOS | core/nixos | |
| NixOS with XFCE | core/nixos_xfce |
There are also core images specific to pine64/phone and pine64/book and jetson/common.
The default configuration creates a user named "core" mapped into a container,
but this can be adjusted with the skiff-core.yaml configuration file:
containers:
core:
image: skiffos/skiff-core-gentoo:latest
[...]
users:
core:
container: core
containerUser: core
[...]The full example config is in the skiff/core package.
To customize a running system, edit /mnt/persist/skiff/core/config.yaml and
run systemctl restart skiff-core to apply. You may need to delete existing
containers and restart skiff-core to re-create them after changing their config.
The config format is defined in the skiff-core repo.
SkiffOS supports modular configuration packages: kernel & buildroot configs, root filesystem overlays, patches, hooks, and other resources.
Layers are named as namespace/name. For example, a Raspberry Pi 4
configuration would be pi/4 and Docker is apps/docker.
├── cflags: compiler flags in files
├── buildroot: buildroot configuration fragments
├── buildroot_ext: buildroot extensions (extra packages)
├── buildroot_patches: extra Buildroot global patches
│ ├── <packagename>: patch files for Buildroot <packagename>
│ └── <packagename>/<version>: patches for package version
├── busybox: busybox configuration fragments
├── extensions: extra commands to add to the build system
│ └── Makefile
├── hooks: scripts hooking pre/post build steps
│ ├── post.sh
│ └── pre.sh
├── kernel: kernel configuration fragments
├── kernel_patches: kernel .patch files
├── root_overlay: root overlay files
├── metadata: metadata files
│ ├── commands
│ ├── dependencies
│ ├── description
│ └── unlisted
├── resources: files used by the configuration package
├── scripts: any scripts used by the extensions
├── uboot: u-boot configuration fragments
├── uboot_patches: u-boot .patch files
└── users: additional buildroot user config files
All files are optional.
To add custom users, add files in the "users" dir with the makeuser syntax.
You can set the following env variables to control this process:
SKIFF_CONFIG_PATH_ODROID_XU: Set the path for the ODROID_XU config package. You can set this to add new packages or override old ones.SKIFF_EXTRA_CONFIGS_PATH: Colon:separated list of paths to look for config packages.SKIFF_CONFIG: Name of skiff config to use, or comma separated list to overlay, with the later options taking precedence
These packages will be available in the SkiffOS system.
It's often useful to be able to adjust the configs during development without actually creating a new configuration layer. This can be easily done with the overrides layer.
The overrides directory is treated as an additional configuration layer. The layout of the configuration layers is described above. Overrides is ignored by Git, and serves as a quick and easy way to modify the configuration.
To apply the changes & re-pack the build, run "make configure compile" again.
Use Workspaces to compile multiple SKIFF_CONFIG combinations simultaneously.
The SKIFF_WORKSPACE environment variable controls which workspace is selected.
The directory at workspaces/$SKIFF_WORKSPACE contains the Buildroot build directory.
Configuration files in overrides/workspaces/$SKIFF_WORKSPACE/ will override
settings for that workspace using the configuration package structure.
The virt/ packages are designed for running Skiff in various virtualized environments.
Here is a minimal working example of running Skiff in Qemu:
$ SKIFF_CONFIG=virt/qemu,util/rootlogin make configure compile
$ make cmd/virt/qemu/runThe util/rootlogin package is used here to enable logging in as "root" on the
qemu debug console shown when running "cmd/virt/qemu/run".
Qemu can emulate other architectures, for example, riscv64:
export SKIFF_WORKSPACE=qemu
export SKIFF_CONFIG=virt/qemu,core/gentoo,util/rootlogin
mkdir -p ./overrides/workspaces/qemu/buildroot
echo "BR2_riscv=y" > ./overrides/workspaces/qemu/buildroot/arch
echo "BR2_PACKAGE_HOST_GENEXT2FS=y
BR2_PACKAGE_HOST_GENIMAGE=y
BR2_PACKAGE_HOST_E2FSPROGS=y" > ./overrides/workspaces/qemu/buildroot/genimage
make compile
Most Buildroot-supported architectures can be selected & emulated.
The parameters for running the VM can also be adjusted:
export ROOTFS_MAX_SIZE=120G
export QEMU_MEMORY=8G
export QEMU_CPUS=8
make cmd/virt/qemu/run
Here is a minimal working example of running SkiffOS in Docker:
$ SKIFF_CONFIG=virt/docker,skiff/core make configure compile
$ make cmd/virt/docker/buildimage
$ make cmd/virt/docker/run
# inside container
$ su - coreThe build command compiles the image, and run executes it.
You can execute a shell inside the container with:
$ make cmd/virt/docker/exec
# alternatively
$ docker exec -it skiff shAlternatively, run the latest demo release on Docker Hub:
docker run -t -d --name=skiff \
--privileged \
--cap-add=NET_ADMIN \
--security-opt seccomp=unconfined \
--stop-signal=SIGRTMIN+3 \
-v /sys/fs/cgroup:/sys/fs/cgroup:ro \
-v $(pwd)/skiff-persist:/mnt/persist \
skiffos/skiffos:latest
SkiffOS can be configured dynamically with files in the "persist" partition.
Set the hostname by placing the desired hostname in the skiff/hostname file on
the persist partition. You could also set this in one of your config packages by
writing the desired hostname to /etc/hostname.
You can use nmcli on the device to manage NetworkManager, and any connection
definitions written by nmcli device wifi connect or similar will automatically
be written to the persist partition and persisted to future boots.
To connect to WiFi: nmcli device wifi connect myssid password mypassword.
The configuration file format for these connections is documented here with examples.
Example for a WiFi network called mywifi with password mypassword:
[connection]
id=mywifi
uuid=12f6c21d-f077-4b95-a4cb-bf41555d87a5
type=wifi
[wifi]
mode=infrastructure
ssid=mywifi
[wifi-security]
key-mgmt=wpa-psk
psk=mypassword
[ipv4]
method=auto
[ipv6]
addr-gen-mode=stable-privacy
method=auto
Network configuration files are plaintext files located at either of:
/etc/NetworkManager/system-connections/inside the build image/mnt/persist/skiff/connections/on the persist partition.
To add the above example to your build:
gedit ./overrides/root_overlay/etc/NetworkManager/system-connections/mywifi- paste the above plaintext & save
- run "make compile" to update the image with the changes.
The system will generate the authorized_keys file for the users on startup.
It takes SSH public key files (*.pub) from these locations:
/etc/skiff/authorized_keysfrom inside the imageskiff/keysfrom inside the persist partition
Your SSH public key will usually be located at ~/.ssh/id_ed25519.pub.
To mount a Linux disk, for example an ext4 partition, to a path inside a
Docker container, you can use the Docker Volumes feature:
# create a volume for the storage drive
docker volume create --driver=local --opt device=/dev/disk/by-label/storage storage
# run a temporary container to view the contents
docker run --rm -it -v storage:/storage --workdir /storage alpine:edge shThe volume can be mounted into a Skiff Core container by adding to the mounts
list in /mnt/persist/skiff/core/config.yaml:
containers:
core:
image: skiffos/skiff-core-gentoo:latest
mounts:
- storage:/mnt/storageAfter adding the mount, delete and re-create the container:
docker rm -f core
systemctl restart skiff-coreSkiffOS is built & supported by Aperture Robotics, LLC.
Community contributions and discussion are welcomed!
Please file a GitHub issue and/or Join Discord with any questions.
... or feel free to reach out on Matrix Chat!