buildroot-s6: s6 Supervision for Embedded Devices

Overview

s6 is small and secure supervision suite. Its companion, s6-rc is a complete service manager.

buildroot is a tool to generate embedded Linux systems.

buildroot-s6 allows the user to build a firmware for an embedded Linux device using s6 and s6-rc as its init system instead of SysV or systemd.

Several predefined configurations to showcase s6 are provided:

• QEMU/x86
• Raspberry Pi
• HardKernel ODROID-C2

How to Build a Firmware

QEMU

In this configuration, all the programs are built using the GNU libc and dynamically linked. To build a firmware, execute:

$ make BR2_EXTERNAL=$PWD/custom O=$PWD/output-x86 -C buildroot demo_s6_qemu_x86_defconfig
$ make O=$PWD/output-x86 -C buildroot

Once the build is finished, the images for QEMU are available in ./output-x86/images. Run it like this:

$ qemu-system-i386 -M pc -kernel output-x86/images/bzImage \
    -drive file=output-x86/images/rootfs.ext2,if=virtio,format=raw \
    -append "root=/dev/vda" \
    -net nic,model=virtio \
    -net user,hostfwd=tcp::2222-:22,hostfwd=tcp::8080-:80

It is possible to connect via SSH to the target using:

$ ssh -p 2222 -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null root@localhost

The web server running on the target can be accessed by opening a web browser at http://localhost:8080.

Raspberry Pi

In this configuration, all the programs are built using musl libc and statically linked. To build a firmware, execute:

$ make BR2_EXTERNAL=$PWD/custom O=$PWD/output-rpi -C buildroot demo_s6_rpi_defconfig
$ make O=$PWD/output-rpi -C buildroot

Once the build is finished, the images for the SD card are available in ./output-rpi/images.

ODROID-C2

In this configuration, all the programs are built using the GNU libc and dynamically linked. To build a firmware, execute:

$ make BR2_EXTERNAL=$PWD/custom O=$PWD/output-odroidc2 -C buildroot demo_s6_odroidc2_defconfig
$ make O=$PWD/output-odroidc2 -C buildroot

Once the build is finished, the images for the SD card are available in ./output-odroidc2/images.