On Tuesday 10 March 2015 13:10:08 Kumar Gala wrote:

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The top level qcom,msm-id and qcom,board-id are utilized by bootloaders

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on Qualcomm MSM platforms to determine which device tree should be
utilized and passed to the kernel.

Cc: <redacted>
Signed-off-by: Kumar Gala <redacted>

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.

To insert platform-local properties that mean nothing outside of the
firmware packaging of the device trees, which is the case here?

I think the idea of having the installer script inserting them is
quite reasonable in this case.


-Olof

These values are static, so not sure what the point of having the installer script do that?

It combines two hacks to work around a nonstandard boot loader.
Once the bootloader is fixed, you can stop using that script.

	Arnd