On Tue, May 5, 2015 at 5:05 AM, Yann Droneaud [off-list ref] wrote:

Hi,

I believe Device Tree Blob (.dtb file) built from kernel's Device Tree
Sources (.dts, which #include .dtsi, which #include .h) using Device
Tree Compiler (dtc) are covered by GNU General Public Licence v2
(GPLv2), but cannot find any reference.

By default yes, but we've been steering people to dual license them GPL/BSD.

As most .dtsi in arch/arm/boot/dts/ are covered by GPLv2, and,
as most .h in include/dt-bindings/ are also covered by GPLv2,
the source code is likely covered by GPLv2.

Then this source code is translated in a different language (flattened
device tree), so the resulting translation is also likely covered by
GPLv2.

So, when I'm proposed to download a .dtb file from a random vendor,
can I require to get the associated source code ?

I believe so yes. However, you already have the "source" for the most
part. Just run "dtc -I dtb -O dts <dtb file>". You loose the
preprocessing and include structure though (not necessarily a bad
thing IMO).

Then the question is what is the license on that generated dts!

Anyway, for a .dtb file generated from kernel sources, it's rather
painful to look after all .dts, .dtsi, .h, to find what kind of
licences are applicables, as some are covered by BSD, dual licensed
(any combination of X11, MIT, BSD, GPLv2).

I imagine the includes cause some licensing discrepancies if you dug into it.

Rob