Boot Source Override feature problems

[Konstantin Aladyshev]

On Wed, Jun 23, 2021 at 8:09 PM Andrei Kartashev <a.kartashev at yadro.com> wrote:
>
> On Wed, 2021-06-23 at 19:36 +0300, Konstantin Aladyshev wrote:
> > We need to have two `xyz.openbmc_project.Object.Enable` interfaces:
> > 1) one that stores information whether the BootSourceOverride feature
> > is enabled or not,
> > 2) another one that stores information whether the BootSourceOverride
> > feature is permanent or one_time.
> >
> > The current implementation has only 1), proposed design has both 1)
> > and 2):
> > ```
> >  /xyz/openbmc_project/control/host0/boot:
> >       - Interface: xyz.openbmc_project.Control.Boot.Source
> >       - Interface: xyz.openbmc_project.Control.Boot.Mode
> >       - Interface: xyz.openbmc_project.Control.Boot.Type
> >       - Interface: xyz.openbmc_project.Object.Enable              <--
> > -------  1)
> >  /xyz/openbmc_project/control/host0/boot/one_time:
> >       - Interface: xyz.openbmc_project.Object.Enable              <--
> > -------  2)
> > ```
> >
>
> Right, but your initial proposal was to use "Permanent" flag instead of
> second one:
>     - Interface: xyz.openbmc_project.Control.Boot.Permanent #
> true/false

To use something like  `xyz.openbmc_project.Control.Boot.Permanent` we
need to create another interface in the `phosphor-dbus-interfaces`
repository, which is something the OpenBMC community want to avoid
without necessities.
As the same functionality can be achieved with the
`xyz.openbmc_project.Object.Enable` interface under
`/xyz/openbmc_project/control/host0/boot` I've decided to take this
approach instead.

>
> BTW, can anyone explain me, why do we have all this as separate
> interfaces with only one properties?
> As for me, it should be one interface
> "xyz.openbmc_project.Control.Boot" with several properties.
>

I don't know.

> > Also earlier there were two sets of Boot.Source/Boot.Mode/Boot.Type
> > settings. But the second one isn't really necessary as the
> > BootSourceOverride feature doesn't fallback to permanent override
> > after one-time override. So we need to keep only one set of
> > Boot.Source/Boot.Mode/Boot.Type settings.
> >
>
> The fact that it was broken doesn't automatically mean that this need
> to be removed. May be it worth to fix this...
>

I didn't mean that something was broken here. I just meant that the
typical BootSourceOverride functionality in a BMC is not intended to
work this way.

> But here I tend to agree that
> "/xyz/openbmc_project/control/host0/boot/one_time" can be wasted. I
> just think it can be wasted completely. Then you can use GetAll on
> /xyz/openbmc_project/control/host0/boot to get all required data.
>

Currently "/xyz/openbmc_project/control/host0/boot/one_time" is used
to keep two separate `xyz.openbmc_project.Object.Enable` objects, so
we can't waste it.


> > Best regards,
> > Konstantin Aladyshev
>
> --
> Best regards,
> Andrei Kartashev
>
>