legal-info: infrastructure to collect legally-relevant material

This allows to automatically collect material that may be needed to comply with
the license of packages that Buildroot prepares for the target device.

The core of the implementation is made by the following parts:
 - in package/pkg-utils.mk some helper functions are defined for common actions
   such as generating a warning, producing info about a package etc;
 - in package/pkg-gentargets.mk, within the GENTARGETS framework, a new
   <PKG>-legal-info target produces all the info for a given package;
 - Makefile implements the top-level targets:
   - legal-info-prepare creates the output directory and produces legal info
     about Buildroot itself and the toolchain, which mostly means just warning
     the user that this is not implemented;
   - legal-info, the only target that is supposed to be used directly, depends
     on all of the above and finishes things by producing the README files from
     the various pieces.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

2 files changed, 28 insertions, 0 deletions

diff --git a/support/legal-info/README.header b/support/legal-info/README.header
new file mode 100644
index 0000000000..3321adb7ed
--- /dev/null
+++ b/support/legal-info/README.header
@@ -0,0 +1,24 @@
+Most of the packages that were used by Buildroot to produce the image files,
+including Buildroot itself, have open-source licenses. It is your
+responsibility to comply to the requirements of these licenses.
+To make this easier for you, Buildroot collected in this directory some
+material you may need to get it done.
+
+This material is composed of the following items.
+ * The scripts used to control compilation of the packages and the generation
+   of image files, i.e. the Buildroot sources.
+   Note: this has not been saved due to technical limitations, you must
+   collect it manually.
+ * The Buildroot configuration file; this has been saved in buildroot.config.
+ * The toolchain (cross-compiler and related tools) used to generate all the
+   compiled programs.
+   Note: this has not been saved due to technical limitations, you must
+   collect it manually.
+ * The source code for all packages; this has been saved in the sources/
+   subdirectory (except for the proprietary packages, which have not been
+   saved); patches applied to some packages by Buildroot are included in the
+   Buildroot sources and were not duplicated in the sources/ subdirectory.
+ * A manifest file listing the configured packages and related information.
+ * The license text of the packages; they have been saved in the licenses/
+   subdirectory.
+
diff --git a/support/legal-info/README.warnings-header b/support/legal-info/README.warnings-header
new file mode 100644
index 0000000000..cd0829069c
--- /dev/null
+++ b/support/legal-info/README.warnings-header
@@ -0,0 +1,4 @@
+Due to technical limitations or lack of license definition in the package
+makefile, some of the material listed above could not been saved, as the
+following list details.
+