Re: [PATCH 2/4] dt-bindings: raspberrypi,bcm2835-firmware: Include 'reboot-mode.yaml'

[Gregor Herburger]

Hi Conor,

On Fri, Jun 26, 2026 at 04:57:35PM +0100, Conor Dooley wrote:
> On Fri, Jun 26, 2026 at 09:35:05AM +0200, Gregor Herburger wrote:
> > The Raspberry Pi firmware allows to set a reboot mode called tryboot
> > that allows to try booting from a different partition to allow updating
> > of the boot partition. Allow reboot mode properties by referencing the
> > reboot-mode schema.
> > 
> > Signed-off-by: Gregor Herburger <gregor.herburger@xxxxxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml    | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
> > index 983ea80eaec97..30b490e0d9fb3 100644
> > --- a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
> > +++ b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
> > @@ -133,11 +133,14 @@ properties:
> >      required:
> >        - compatible
> >  
> > +allOf:
> > +  - $ref: /schemas/power/reset/reboot-mode.yaml#
> > +
> >  required:
> >    - compatible
> >    - mboxes
> >  
> > -additionalProperties: false
> > +unevaluatedProperties: false
> 
> I think you should keep additionalProperties: false and add
> mode-normal: true
> mode-tryboot: true
> 
> (I don't know if the latter works though, you may need to have a $ref to
> uint32-array).
> 
> What you've done permits freeform reboot modes, but I think only normal
> and tryboot are valid?

Ah yes good point. I do think it should be restricted to
'mode-{normal,tryboot}'. 

Sashiko also suggested to set maxItems to 1 and I think that is a good idea as
well, because afaik the firmware only accepts a 32bit value for the reboot flag.
The $ref to uin32 is not needed that is already enforced by the
patternProperties "^mode-.*$": in reboot-mode.yaml.

Therefore I will add the following (and keep additionalProperties: false):

properties:
...

  mode-normal:
    maxItems: 1

  mode-tryboot:
    maxItems: 1

allOf:
  - $ref: /schemas/power/reset/reboot-mode.yaml#


I will do some more testing and send a v2 later.

Regards
-- 
Gregor Herburger
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