Re: [Automated-testing] Plumbers Testing MC potential topic: specialised toolchains

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Tue, 2024-07-09 at 00:10 +0200, Guillaume Tucker via
lists.yoctoproject.org wrote:
> Based on these assumptions, the issue is about reproducibility -
> yet alone setting up a toolchain that can build the code at all.
> For an automated system to cover these use-cases, or for any
> developer wanting to work on these particular areas of the
> kernel, having the ability to reliably build it in a reproducible
> way using a reference toolchain adds a lot of value.  It means
> better quality control, less scope for errors and unexpected
> behaviour with different code paths being executed or built
> differently.
> 
> The current state of the art are the kernel.org toolchains:
> 
>   https://mirrors.edge.kernel.org/pub/tools/
> 
> These are for LLVM and cross-compilers, and they already solve a
> large part of the issue described above.  However, they don't
> include Rust (yet), and all the dependencies need to be installed
> manually which can have a significant impact on the build
> result (gcc, binutils...).  One step further are the Linaro
> TuxMake Docker images[2] which got some very recent blog
> coverage[3].  The issues then are that not all the toolchains are
> necessarily available in Docker images, they're tailored to
> TuxMake use-cases, and I'm not sure to which extent upstream
> kernel maintainers rely on them.
> 
> 
> Now, I might have missed some other important aspects so please
> correct me if this reasoning seems flawed in any way.  I have
> however seen how hard it can be for automated systems to build
> kernels correctly and in a way that developers can reproduce, so
> this is no trivial issue.  Then for the Testing MC, I would be
> very interested to hear whether people feel it would be
> beneficial to work towards a more exhaustive solution supported
> upstream: kernel.org Docker images or something close such as
> Dockerfiles in Git or another type of images with all the
> dependencies included.  How does that sound?

Sadly I can't be at plumbers however I wanted to mention that Yocto
Project's SDKs are effectively standalone toolchains. They can be
configured to contain all their dependencies and whatever tools are
desirable (e.g. git, python etc.), are fully reproducible, installable
at any location and we have working rust compilers in the SDKs if
configured to include them.

I just want to make sure people know that capability exists!

Cheers,

Richard