[PATCH 00/21] Qualcomm generic board support

[Sumit Garg]

On Mon, 4 Dec 2023 at 16:30, Daniel Thompson <daniel.thompson at linaro.org> wrote:
>
> On Mon, Dec 04, 2023 at 11:02:57AM +0530, Sumit Garg wrote:
> > + Linux kernel DT bindings maintainers, EBBR ML
> >
> > On Thu, 30 Nov 2023 at 20:05, Tom Rini <trini at konsulko.com> wrote:
> > > On Thu, Nov 30, 2023 at 01:02:25PM +0530, Sumit Garg wrote:
> > > > On Wed, 29 Nov 2023 at 22:06, Neil Armstrong <neil.armstrong at linaro.org> wrote:
> > > > > > I've been thinking about and hacking on this for the last week or so,
> > > > > > sorry for the delayed reply here.
> > > > > >
> > > > > > The value is in preventing any of the existing bindings from regressing,
> > > >
> > > > That is actually best addressed in Linux by checking the DTS against
> > > > yaml DT bindings. We don't have that testing available in u-boot and
> > > > only depend on careful reviews.
> > >
> > > I would absolutely love for someone to make another attempt at updating
> > > our kbuild infrastucture so that we can run the validation targets.
> > >
> >
> > Given that EBBR requires [1] the platform (firmware/bootloader) and
> > not OS to supply the devicetree, it becomes evident that
> > firmware/bootloaders import DTS from Linux kernel (where it is
> > maintained).
> >
> > But currently u-boot doesn't have a proper way to validate those DTS
> > against DT bindings (maintained in Linux kernel). Although there are
> > Devicetree schema tools available here [2], there isn't a versioned
> > release package of DT bindings which one should use to validate DTS
> > files.
>
> The kernel is regularly released in multiple forms (including git
> tags and tarball). Why isn't the kernel itself sufficient to be a
> versioned release of the DT bindings directory?
>

The Linux kernel may come in various forms (upstream vs stable vs
vendor). It's difficult to decide from where the DT bindings should
come from. Should they come from upstream or should they come from the
kernel which is actually booted onto a particular device?

IOW, as of now which kernel version should u-boot pick up for DT
validation checks?

If we can have a separate release cadence for DT bindings then the
platform (firmware/bootloader) can attest the DTB against that. Later
one should be able to boot any kernel with the DTB provided by
platform.

-Sumit

>
> Daniel.