CONTRIBUTING.md: mention license and SPDX

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/134
[ Mention LGPL is preferred, even for tools/ ]
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 8648eba4772b071f316f04a709d8fdbc26bd2c70..5abcf7aa6a3ff6586f1bb2c7566045917841a676 100644 (file)
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -7,6 +7,7 @@ patches sent to the [mailing list]. In addition you can open issues and feature
 requests on our [GitHub tracker].
 
 In this file you can find:
+  * [License and SPDX](#license-and-spdx)
   * [Commit style and history](#commit-style-and-history)
   * [Using commit trailers](#using-commit-trailers)
     + [Signed-off-by](#signed-off-by)
@@ -19,6 +20,13 @@ In this file you can find:
   * [Tools manual pages](#tools-manual-pages)
   * [Tools shell completion](#tools-shell-completion)
 
+## License and SPDX
+
+The project uses `GPLv2+` for `tools/` and `LGPLv2.1+` for everything else.
+New tools should be licensed under `LGPLv2.1+` to make it easy to migrate code
+to other places when/if needed. When adding new files use the respective
+`SPDX-License-Identifier:` instead of the complete license text.
+
 ## Commit style and history
 
 The kmod project uses a [linear, "recipe" style] history. This means that