[PATCH v2 1/3] devicetree: bindings: Document qcom, msm-id and qcom, board-id

Arnd Bergmann
2015-03-09T12:11:26Z

On Friday 06 March 2015 14:37:52 Kumar Gala wrote:
> On Mar 6, 2015, at 1:15 PM, Olof Johansson <olof@lixom.net> wrote:
>
> > On Fri, Mar 6, 2015 at 8:08 AM, Kumar Gala <galak@codeaurora.org> wrote:
> >>
> >> On Mar 5, 2015, at 7:59 PM, Olof Johansson <olof@lixom.net> wrote:
> >>
> >>> On Thu, Mar 5, 2015 at 12:23 PM, Kumar Gala <galak@codeaurora.org> wrote:
> >>>>
> >>>> On Mar 5, 2015, at 1:42 PM, Kevin Hilman <khilman@kernel.org> wrote:
> >>>>
> >>>>> Kumar Gala <galak@codeaurora.org> writes:
> >>>>>
> >>>>>> The top level qcom,msm-id and qcom,board-id are utilized by bootloaders
> >>>>>> on Qualcomm MSM platforms to determine which device tree should be
> >>>>>> utilized and passed to the kernel.
> >>>>>>
> >>>>>> Cc: <devicetree@vger.kernel.org>
> >>>>>> Signed-off-by: Kumar Gala <galak@codeaurora.org>
> >>>>>
> >>>>> Is this the special magic that allows qcom bootloaders to take a kernel
> >>>>> plus multiple DTBs and figure out which DTB to pass?
> >>>>>
> >>>>> Kevin
> >>>>
> >>>> yes
> >>>
> >>> That's a bummer.
> >>>
> >>> Luckily, the solution for upstream is still quite simple: Provide only
> >>> one devicetree, and it'll be used, right?
> >>
> >> We can provide only one, we still need the IDs in the DT.
> >
> > How are the DTS provided? Concatenated with the kernel, or in a
> > wrapped data format? Or in a separate partition from the kernel?
>
> Its a wrapped data format that is than concatenated with the kernel if I remember correctly.

Then you should be able to create a tool that can write this concatenated
format and insert these properties from a table that matches the boot
loader, right?

Arnd