Re: Device Tree Blob (DTB) licence

[Yann Droneaud]

Hi,

[removing Cc: licensing@xxxxxxx]

Le vendredi 22 mai 2015 Ã 12:05 +0200, Yann Droneaud a Ãcrit :
> Le mardi 05 mai 2015 Ã 11:41 -0500, Rob Herring a Ãcrit :
> > On Tue, May 5, 2015 at 5:05 AM, Yann Droneaud <ydroneaud@xxxxxxxxxx
> > > 
> > wrote:
> > > 
> > > 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.
> > 
> 
> Can you give me the rationale behind such dual licenses requirement ?
> 
> If a BSD .dts includes GPLv2 .h, the whole is covered by GPLv2,
> so I cannot find a case where a BSD covered .dts file could be used
> alone within BSD license rights.
> 
> > > 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!
> > 
> 
> That's also a good question.
> 
> Is this a form a "reverse engineering" with all the legalese burden ?
> 
> Anyway without a clear information attached to the DTB, it's 
> difficult
> to tell which licence cover the "decompiled" version.
> 
> > > 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.
> > 
> 
> It's a pity, and it's probably something to sort out.
> 
> DTB files produced as part of kernel compilation should have a well
> known license attached by default.
> 

I've added licensing@xxxxxxxx in Cc: in my previous message to have an 
advice on this subject, but I failed to notice licensing@xxxxxxx 
is not a mailing list: I was assigned request ID [gnu.org #1017262].

Regards.

-- 
Yann Droneaud
OPTEYA
> --- Begin Message ---
> This message has been automatically generated in response to a
> licensing question you sent to the Free Software Foundation, with subject:
> 	"Re: Device Tree Blob (DTB) licence".
>
> There is no need to reply to this message right now.  Your request has
> been assigned an ID of [gnu.org #1017262].
>
> Please include the string:
>          [gnu.org #1017262]
> in the subject line of all future correspondence about this issue.  To do
> so, you may reply to this message.
>
>
> Thank you so much for writing to the Free Software Foundation's
> Licensing and Compliance Lab. Questions sent to this address are
> answered largely by volunteers, with the help of FSF staff. We have the
> following licensing resources available which you might find helpful:
>
> Licensing FAQ page: http://www.gnu.org/licenses/gpl-faq.html
> Text of the GNU GPL: http://www.gnu.org/licenses/gpl.html
> Text of the GNU LGPL: http://www.gnu.org/licenses/lgpl.html
> Text of the GNU AGPL: http://www.gnu.org/licenses/agpl.html
> Our license list page: http://www.gnu.org/licenses/license-list.html
>
> We can always use more help in answering licensing questions (check out
> our license team page on Libreplanet if you are interested in helping
> out <http://libreplanet.org/wiki/Group:Free_Software_Foundation/Licensing_Volunteers>),
> so we thank you for your patience as you await a response. You can also
> help the licensing team by making a donation at <donate.fsf.org>. Your donations are
> what enable us to offer this service to the community.
>
> We do offer consulting services for companies who are working to develop
> products that incorporate free software so that they can do so in ways
> that comply with the terms of the GPL and other free software licenses.
> If you are interested in this service, please write a separate message
> to compliance-lab@xxxxxxxx
>
>                         Sincerely,
>                         FSF GPL Compliance Lab Office
>
> --- End Message ---