[PATCH v2 00/41] Initial implementation of standard boot

[Peter Robinson]

On Thu, Oct 28, 2021 at 6:47 PM Tom Rini <trini at konsulko.com> wrote:
>
> On Thu, Oct 28, 2021 at 06:37:42PM +0100, Peter Robinson wrote:
> > On Wed, Oct 27, 2021 at 3:11 PM Simon Glass <sjg at chromium.org> wrote:
> > >
> > > Hi Heinrich,
> > >
> > > On Wed, 27 Oct 2021 at 05:38, Heinrich Schuchardt
> > > <heinrich.schuchardt at canonical.com> wrote:
> > > >
> > > >
> > > >
> > > > On 10/24/21 01:25, Simon Glass wrote:
> > > > >
> > > > > The bootflow feature provide a built-in way for U-Boot to automatically
> > > > > boot an Operating System without custom scripting and other customisation.
> > > > > This is called 'standard boot' since it provides a standard way for
> > > > > U-Boot to boot a distro, without scripting.
> > > > >
> > > > > It introduces the following concepts:
> > > > >
> > > > >     - bootdev - a device which can hold a distro
> > > > >     - bootmeth - a method to scan a bootdev to find bootflows (owned by
> > > > >                  U-Boot)
> > > > >     - bootflow - a description of how to boot (owned by the distro)
> > > >
> > > > Please, describe why you are suggesting this change.
> > > >
> > > > Replacing a script by a devicetree chunk is just decreasing flexibility
> > > > and increasing complexity. Where is the benefit?
> > > >
> > > > I am missing a description here of where and how a boot flow shall be
> > > > defined. Describing some device-tree binding in patch 40/41 does not
> > > > replace describing the development and usage workflow. Who will provide
> > > > which bootflow information when?
> > > >
> > > > You still have an open discussion with Linaro about the source of
> > > > devicetrees. This discussion needs to be finalized before considering
> > > > this series.
> > > >
> > > > In my view bootflows cannot be defined in the devicetree because prior
> > > > firmware providing a devicetree is completely independent of any distro
> > > > and therefore cannot provide a distro specific bootflow.
> > >
> > > There is actually no need to use devicetree here. I think you might
> > > have the wrong end of the stick. It is certainly possible to add nodes
> > > to configure things, if needed, but it works find without any changes
> > > to the devicetree, as you can see from the rpi_3 patch.
> > >
> > > There are several aims with this effort:
> > >
> > > - Provide a standard way to boot anything on U-Boot, that everyone can
> > > plug into (distros, board vendors, people using a custom flow)
> >
> > I as a distro maintainer don't want this, we already get the "standard
> > way to boot" from UEFI, this just feels like another unnecessary
> > abstraction to that.
>
> Right.  But part of the problem is "How do I find UEFI".  Something
> somewhere needs to be configurable to say where to look, yes?

Is this question from the board PoV, the developer of U-Boot or the
distro trying to boot?

If you mean from a boot flow PoV for UEFI to find the HW that contains
the OS to boot I thought that was handled elsewhere in the series.