Adding upstream version 2.10.0+dfsg.upstream/2.10.0+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/docs/process/platform-ports-policy.rst b/docs/process/platform-ports-policy.rst
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+Platform Ports Policy
+=====================
+
+This document clarifies a couple of policy points around platform ports
+management.
+
+Platform compatibility policy
+-----------------------------
+
+Platform compatibility is mainly affected by changes to Platform APIs (as
+documented in the :ref:`Porting Guide`), driver APIs (like the GICv3 drivers) or
+library interfaces (like xlat_table library). The project will try to maintain
+compatibility for upstream platforms.
+
+Due to evolving requirements and enhancements, there might be changes affecting
+platform compatibility, which means the previous interface needs to be deprecated
+and a new interface introduced to replace it. In case the migration to the new
+interface is trivial, the contributor of the change is expected to make good
+effort to migrate the upstream platforms to the new interface.
+
+The project will generally not take into account downstream platforms. If those
+are affected by a deprecation / removal decision, we encourage their maintainers
+to upstream their platform code or copy the latest version of the code being
+deprecated into their downstream tree.
+
+The deprecated interfaces are listed inside :ref:`Release Processes` as well as
+the release after which each one will be removed. When an interface is
+deprecated, the page must be updated to indicate the release after which the
+interface will be removed. This must be at least 1 full release cycle in future.
+For non-trivial interface changes, an email should be sent out to the `TF-A
+public mailing list`_ to notify platforms that they should migrate away from the
+deprecated interfaces. Platforms are expected to migrate before the removal of
+the deprecated interface.
+
+Deprecation policy
+------------------
+
+If a platform, driver or library interface is no longer maintained, it is best
+to deprecate it to keep the projects' source tree clean and healthy. Deprecation
+can be a 1-stage or 2-stage process (up to the maintainers).
+
+ - *2-stage*: The source code can be kept in the repository for a cooling off
+   period before deleting it (typically 2 release cycles). In this case, we keep
+   track of the *Deprecated* version separately from the *Deleted* version.
+
+ - *1-stage*: The source code can be deleted straight away. In this case, both
+   versions are the same.
+
+The :ref:`Platform Ports` page provides a list of all deprecated/deleted
+platform ports (or soon to be) to this day.
+
+--------------
+
+*Copyright (c) 2018-2023, Arm Limited and Contributors. All rights reserved.*
+
+.. _TF-A public mailing list: https://lists.trustedfirmware.org/mailman3/lists/tf-a.lists.trustedfirmware.org/