[Buildroot] Buildroot on Windows Subsystem for Linux (WSL)

[Buildroot] Buildroot on Windows Subsystem for Linux (WSL)

[Christian Stewart]

Hi all,

Windows Subsystem for Linux 1.0 runs a userspace without a kernel, and
2.0 runs a full Linux Kernel inside a VM.

SkiffOS, using Buildroot, now supports WSL with the "virt/wsl" package.
This could be extracted from Skiff and submitted to mainline Buildroot
as a "board" configuration as well.

https://github.com/skiffos/SkiffOS/tree/master/configs/virt/wsl

The Buildroot system works as expected in the WSL environment. The
buildroot output tar.gz can be imported directly into WSL 2.0. WSL 1.0
requires using the WSL-DistroLauncher project to load the distribution
via a Windows Appx.

This is an interesting way to use Buildroot under Windows.

Best regards,
Christian Stewart

[Buildroot] Buildroot on Windows Subsystem for Linux (WSL)

[Peter Korsgaard]

>>>>> "Christian" == Christian Stewart <christian@paral.in> writes:

 > Hi all,

 > Windows Subsystem for Linux 1.0 runs a userspace without a kernel, and
 > 2.0 runs a full Linux Kernel inside a VM.

 > SkiffOS, using Buildroot, now supports WSL with the "virt/wsl" package.
 > This could be extracted from Skiff and submitted to mainline Buildroot
 > as a "board" configuration as well.

 > https://github.com/skiffos/SkiffOS/tree/master/configs/virt/wsl

 > The Buildroot system works as expected in the WSL environment. The
 > buildroot output tar.gz can be imported directly into WSL 2.0. WSL 1.0
 > requires using the WSL-DistroLauncher project to load the distribution
 > via a Windows Appx.

 > This is an interesting way to use Buildroot under Windows.

Cute. Besides the fact that you are booting a (heavily patched) Linux
kernel, is there any specific advantages to just creating a docker
container or a classic VM from a Buildroot build?

-- 
Bye, Peter Korsgaard

[Buildroot] Buildroot on Windows Subsystem for Linux (WSL)

[Christian Stewart]

Hi Peter,

On Mon, Jan 18, 2021 at 12:15 PM Peter Korsgaard <peter@korsgaard.com> wrote:
>
> >>>>> "Christian" == Christian Stewart <christian@paral.in> writes:
>  > The Buildroot system works as expected in the WSL environment. The
>  > buildroot output tar.gz can be imported directly into WSL 2.0. WSL 1.0
>  > requires using the WSL-DistroLauncher project to load the distribution
>  > via a Windows Appx.
>
>  > This is an interesting way to use Buildroot under Windows.
>
> Cute. Besides the fact that you are booting a (heavily patched) Linux
> kernel, is there any specific advantages to just creating a docker
> container or a classic VM from a Buildroot build?

By my (limited) understanding, WSL2 promises tighter integration
between Linux and the Windows OS.

I haven't tested it, but docs say you can override the kernel image.

It forces a wsl-provided /init binary, which forks several times to
consume PID 1, 2, 3.

https://github.com/microsoft/WSL2-Linux-Kernel/issues/30#issuecomment-698922943

According to this, Windows 10 insider builds 20201 or above, you can
add a custom init process:

Adding to /etc/wsl.conf inside the VM:

[boot]
command = "/my-init"

However, the my-init binary will not run as PID 1.

I am working on a workaround similar to the "systemd-genie" project to
create a PID namespace and run systemd as PID 1 inside that.

Best regards,
Christian Stewart

[Buildroot] Buildroot on Windows Subsystem for Linux (WSL)

[Peter Korsgaard]

>>>>> "Christian" == Christian Stewart <christian@paral.in> writes:

 > Hi Peter,
 > On Mon, Jan 18, 2021 at 12:15 PM Peter Korsgaard <peter@korsgaard.com> wrote:
 >> 
 >> >>>>> "Christian" == Christian Stewart <christian@paral.in> writes:
 >> > The Buildroot system works as expected in the WSL environment. The
 >> > buildroot output tar.gz can be imported directly into WSL 2.0. WSL 1.0
 >> > requires using the WSL-DistroLauncher project to load the distribution
 >> > via a Windows Appx.
 >> 
 >> > This is an interesting way to use Buildroot under Windows.
 >> 
 >> Cute. Besides the fact that you are booting a (heavily patched) Linux
 >> kernel, is there any specific advantages to just creating a docker
 >> container or a classic VM from a Buildroot build?

 > By my (limited) understanding, WSL2 promises tighter integration
 > between Linux and the Windows OS.

 > I haven't tested it, but docs say you can override the kernel image.

You haven't tested it? Didn't the defconfig you point to build a Linux
kernel as well?

-- 
Bye, Peter Korsgaard