migration/release-notes-4.3: Add extra notes

(From yocto-docs rev: c365f3d02ed880d4cd3f7970094249780d443b2f)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Reviewed-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/migration-guides/migration-4.3.rst

@@ -9,6 +9,23 @@ Migration notes for 4.3 (nanbield)
 This section provides migration information for moving to the Yocto
 Project 4.3 Release (codename "nanbield") from the prior release.
 
+.. _migration-4.3-supported-kernel-versions:
+
+Supported kernel versions
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The :term:`OLDEST_KERNEL` setting has been changed to "5.15" in this release, meaning that
+out the box, older kernels are not supported. There were two reasons for this.
+Firstly it allows glibc optimisations that improve the performance of the system
+by removing compatibility code and using modern kernel APIs exclusively. The second
+issue was this allows 64 bit time support even on 32 bit platforms and resolves Y2038
+issues.
+
+It is still possible to override this value and build for older kernels, this is just
+no longer the default supported configuration. This setting does not affect which
+kernel versions SDKs will run against and does not affect which versions of the kernel
+can be used to run builds.
+
 .. _migration-4.3-supported-distributions:
 
 Supported distributions
@@ -27,7 +44,7 @@ Go language changes
 
 -  Support for the Glide package manager has been removed, as ``go mod``
    has become the standard.
-  
+
 .. _migration-4.3-recipe-changes:
 
 Recipe changes
@@ -36,6 +53,15 @@ Recipe changes
 -  Runtime testing of ptest now fails if no test results are returned by
    any given ptest.
 
+.. _migration-4.3-class-changes:
+
+Class changes
+~~~~~~~~~~~~~
+
+-  The ``perl-version`` class no longer provides the ``PERLVERSION`` and ``PERLARCH`` variables
+   as there were no users in any core layer. The functions for this functionality
+   are still available.
+
 .. _migration-4.3-removed-variables:
 
 Removed variables
@@ -43,6 +69,9 @@ Removed variables
 
 The following variables have been removed:
 
+-  ``PERLARCH``
+-  ``PERLVERSION``
+
 .. _migration-4.3-removed-recipes:
 
 Removed recipes

documentation/migration-guides/release-notes-4.3.rst

@@ -16,6 +16,10 @@ New Features / Enhancements in 4.3
 
 -  New core recipes:
 
+-  New classes:
+
+   - A ``ptest-cargo`` class was added to allow Cargo based recipes to easily add ptests
+
 -  QEMU/runqemu enhancements:
 
 -  Image-related enhancements:
@@ -37,6 +41,13 @@ New Features / Enhancements in 4.3
 
 -  Miscellaneous changes:
 
+   -  Git based recipes in OE-Core which used the git protocol have been
+      changed to use https where possibile. https is now believed to be
+      faster and more reliable.
+
+   -  The ``os-release`` recipe added a ``CPE_NAME`` to the fields provided, with the
+      default being populated from :term:`DISTRO`.
+
 Known Issues in 4.3
 ~~~~~~~~~~~~~~~~~~~