On Fri, May 1, 2020 at 7:17 AM Joel Sherrill <j...@rtems.org> wrote: > > This now captures historical rationale alone with cross-linking along
ACK this patch > code templates with license guidelines. > > Closes #3962. > --- > eng/coding-conventions.rst | 19 ++++----- > eng/license-requirements.rst | 91 > +++++++++++++++++++++++++++++++++++++++++--- > 2 files changed, 96 insertions(+), 14 deletions(-) > > diff --git a/eng/coding-conventions.rst b/eng/coding-conventions.rst > index 488ee26..10034df 100644 > --- a/eng/coding-conventions.rst > +++ b/eng/coding-conventions.rst > @@ -33,15 +33,16 @@ Source Documentation > Licenses > -------- > > -* The RTEMS `License <https://devel.rtems.org/wiki/TBR/Website/License>`_. > is the typical > - and preferred license. > - * 2- and 3-clause BSD, MIT, and other OSI-approved non-copyleft licenses > - that permit statically linking with the code of different licenses > - are acceptable. > - * GPL licensed code is NOT acceptable, neither is LGPL. > - See `this blog post explanation > <http://gedare-csphd.blogspot.com/2013/05/software-licenses-with-rtems.html>`_. > - for more information. > - * Advertising obligations are NOT acceptable, but restrictions are > permissible. > +The RTEMS Project has strict requirements on the types of software licenses > +that apply to software it includes and distributes. Submissions will be > +summarily rejected that do not follow the correct license or file header > +requirements. > + > +* Refer to :ref:`LicensingRequirements` for a discussion of the acceptable > + licenses and the rationale. > + > +* Refer to :ref:`FileHeaderCopyright` for example copyright/license comment > + blocks for various languages. > > Language and Compiler > --------------------- > diff --git a/eng/license-requirements.rst b/eng/license-requirements.rst > index 44814b1..b2720f2 100644 > --- a/eng/license-requirements.rst > +++ b/eng/license-requirements.rst > @@ -9,8 +9,10 @@ Licensing Requirements > ********************** > > All artifacts shall adhere to RTEMS Project licensing > -requirements. Currently, the preferred licenses are CC-BY-SA-4.0 license > -for documentation and "Two Paragraph BSD" for source code. > +requirements. Currently, the preferred licenses are: > + > +* "Two Clause BSD" (BSD-2-Clause) for source code, and > +* CC-BY-SA-4.0 license for documentation > > Historically, RTEMS has been licensed under the GPL v2 with linking > exception (https://www.rtems.org/license). It is preferred that new > @@ -19,7 +21,86 @@ previously submitted code to RTEMS under a historical > license, please > grant the project permission to relicense. See > https://devel.rtems.org/ticket/3053 for details. > > -TBD - Convert the following to Rest and insert into this file > -TBD - https://devel.rtems.org/wiki/Developer/Coding/Conventions#Licenses > +For example templates for what to include in source code and > +documentation, see :ref:`FileHeaderCopyright`. > + > + > +Rationale > +--------- > +.. COMMENT: Thanks to Gedare Bloom for his 2013 blog which > +.. COMMENT: discussed the rationale for RTEMS License section. > +.. COMMENT: > http://gedare-csphd.blogspot.com/2013/05/software-licenses-with-rtems.html > + > +RTEMS is intended for use in real-time embedded systems in which the > +application is statically linked with the operating system and all > +support libraries. Given this use case, the RTEMS development team > +evaluated a variety of licenses with with the goal of promoting use > +while protecting both users and the developers. > + > +Using the GNU General Public License Version 2 (GPLv2) unmodified > +was considered but discarded because the GPL can only be linked statically > +with other GPL code. Put simply, linking your application code statically > +with GPL code would cause your code to become GPL code. This would force > +both licensing and redistribution requirements onto RTEMS users. This > +was completely unacceptable. > + > +The GNU Lesser General Public License Version 2 (LGPLv2) was also > +considered and deemed to not be a suitable license for RTEMS. This is > +because it either requires use of a shared library that can be re-linked, > +or release of the linked (application) code. This would require an > +RTEMS-based embedded system to provide a "relinking kit." Again, this > +license would force an unacceptable requirement on RTEMS users and deemed > +unacceptable. > + > +Newer versions of the GPL (i.e. version 3) are completely unsuitable > +for embedded systems due to the additions which add further restrictions > +on end user applications. > + > +The historical RTEMS `License <https://www.rtems.org/license>`_ is a > +modified version of the GPL version 2 that includes an exception to permit > +including headers and linking against RTEMS object files statically. This > +was based on the license used by GCC language runtime libraries at that > +time. This license allows the static linking of RTEMS with applications > +without forcing obligations and restrictions on users. > + > +A problem for RTEMS is there are no copyleft licenses that are compatible > +with the deployment model of RTEMS. Thus, RTEMS Project has to reject any > +code that uses the GPL or LGPL, even though RTEMS has historically appeared > +to use the GPL itself -- but with the exception for static linking, and also > +because an upstream GPL version 2 project could at any time switch to > +GPL version 3 and become totally unusable. In practice, RTEMS can only > +accept original code contributed under the RTEMS License and code that > +has a permissive license. > + > +As stated above, the RTEMS Project has defined its preferred licenses. > +These allow generation of documentation and software from specification > +as well as allow end users to statically link with RTEMS and not incur > +obligations. > + > +In some cases, RTEMS includes software from third-party projects. In those > +cases, the license is carefully evaluated to meet the project licensing > +goals. The RTEMS Project can only include software under licenses which > follow > +these guidelines: > + > +* 2- and 3-clause BSD, MIT, and other OSI-approved non-copyleft licenses > + that permit statically linking with the code of different licenses > + are acceptable. > + > +* The historical RTEMS `License <https://www.rtems.org/license>`_ is > + acceptable for software already in the tree. This software is being > + relicensed to BSD-2-Clause, rewritten, or removed. > + > +* GPL licensed code is NOT acceptable, neither is LGPL. > + > +* Software which is dual-licensed in a manner which prevents free use > + in commercial applications is not acceptable. > + > +* Advertising obligations are not acceptable. > + > +* Some license restrictions may be permissible. These will be considered > + on a case-by-case basis. > > -TBD - Review and make sure this includes info on BSD variants > +In practice, these guidelines are not hard to follow. Critically, > +they protect the freedom of the RTEMS source code and that of end users > +to select the license and distribution terms they prefer for their > +RTEMS-based application. > -- > 1.8.3.1 > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
