[Buildroot] [PATCH 0/3] Support for out-of-tree Buildroot customization

[Yann E. MORIN <yann.morin.1998@free.fr>]

Thomas, All,

On 2013-09-12 20:33 +0200, Thomas Petazzoni spake thusly:
> On Thu, 12 Sep 2013 18:25:40 +0000, ANDY KENNEDY wrote:
> 
> > This sounds much like the way Linux does things for the IP related
> > drivers.  Is that the intent we are going for (personally, I think this
> > is a GREAT idea, as it allows companies to have IP related widgets in
> > BuildRoot without the fear of being REQUIRED to push back their secret
> > sauce)?
> > 
> > If that is what you intend, you have my vote!
> 
> I am not sure what you mean by "IP related drivers". Do you mean
> proprietary drivers?
> 
> It is true that the BR2_EXTERNAL thing raises a licensing question:
> should the BR2_EXTERNAL contents also be released under GPLv2, like the
> rest of Buildroot? Do we really want the root filesystem overlays and
> other highly project-specific contents be released under GPLv2 ?

IANAL, this is not legal advice, talk to your lawyer.

Here are however my toughts on this:

 1- all the Config.in and package.mk files, plus the external.mk file,
    and all other files sourced or otherwise included by a file from
    Buildroot (and thus use Buildroot's infrastructure) could be
    considered a derived work of Buildroot, and thus must be licensed
    with a compatible license,
 2- the defconfigs could be considered as what the GPL identifies as the
    "scripts used to control compilation and installation of the
    executable", since without the .config file, an end-user can not
    reproduce the executable(s),
 3- everything else might be considered not a derived work of Buildroot,
    and might not be required to be licensed with a license compatible
    with Buildroot's license.

Explanations:

1- It's not because it is to be licensed under a license compatible with
   the Buildroot  license that it *has* to be distributed. Just that if
   it *is* distributed, the licensing terms on that should be compatible
   with Buildroot's licensing terms.

2- That's because Buildroot will most probably build a GPL/LGPL program
   that will end up in the ytarget that this applies, because of the
   license of those programs, not because of Buildroot's license. Even
   if Buildroot was under a different license, this would still apply as
   long as a GPL/LGPL program ends up in the target.

3- By "everything else", I mean: a package (in Buildroot's terminology:
   the Config.in and associated .mk file) that directly embbeds the source
   files (.c and .h and ...) for this package (like the host-mkpasswd).
   These source files can not be considered a derived work of Buildroot,
   so Buildroot's license does not apply to those.

So, I think the make legal-stuff should descend into BR2_EXTERNAL, as if
it was an integral part of Buildroot.

BR2_EXTERNAL is here *just* to separate parts of the recipes from the
upstream ones, as a mean to clearly separate local changes from the
upstream reference.

But again: IANAL, this is not legal advice, talk to your legal counsel.

Regards,
Yann E. MORIN.

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