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

Kumar Gala galak at codeaurora.org
Tue Mar 10 10:13:46 PDT 2015


On Mar 9, 2015, at 7:11 AM, Arnd Bergmann <arnd at arndb.de> wrote:

> On Friday 06 March 2015 14:37:52 Kumar Gala wrote:
>> On Mar 6, 2015, at 1:15 PM, Olof Johansson <olof at lixom.net> wrote:
>> 
>>> On Fri, Mar 6, 2015 at 8:08 AM, Kumar Gala <galak at codeaurora.org> wrote:
>>>> 
>>>> On Mar 5, 2015, at 7:59 PM, Olof Johansson <olof at lixom.net> wrote:
>>>> 
>>>>> On Thu, Mar 5, 2015 at 12:23 PM, Kumar Gala <galak at codeaurora.org> wrote:
>>>>>> 
>>>>>> On Mar 5, 2015, at 1:42 PM, Kevin Hilman <khilman at kernel.org> wrote:
>>>>>> 
>>>>>>> Kumar Gala <galak at 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 at vger.kernel.org>
>>>>>>>> Signed-off-by: Kumar Gala <galak at 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

Are you suggesting the tool insert the properties in the DT?  I’m not sure I understand what the point of doing that would be.

- k

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