1.. SPDX-License-Identifier: CC-BY-SA-2.0-UK 2 3Release 4.3 (nanbield) 4======================== 5 6Migration notes for 4.3 (nanbield) 7------------------------------------ 8 9This section provides migration information for moving to the Yocto 10Project 4.3 Release (codename "nanbield") from the prior release. 11 12.. _migration-4.3-supported-kernel-versions: 13 14Supported kernel versions 15~~~~~~~~~~~~~~~~~~~~~~~~~ 16 17The :term:`OLDEST_KERNEL` setting has been changed to "5.15" in this release, meaning that 18out the box, older kernels are not supported. There were two reasons for this. 19Firstly it allows glibc optimisations that improve the performance of the system 20by removing compatibility code and using modern kernel APIs exclusively. The second 21issue was this allows 64 bit time support even on 32 bit platforms and resolves Y2038 22issues. 23 24It is still possible to override this value and build for older kernels, this is just 25no longer the default supported configuration. This setting does not affect which 26kernel versions SDKs will run against and does not affect which versions of the kernel 27can be used to run builds. 28 29Layername override implications 30~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 31 32Code can now know which layer a recipe is coming from through the newly added 33:term:`FILE_LAYERNAME` variable and the ``layer-<layername> override``. This is being used 34for enabling QA checks on a per layer basis. For existing code this has the 35side effect that the QA checks will apply to things being bbappended to recipes 36from other layers. Those other layers would need to have patch upstream status 37entries for patches being bbappended for example. 38 39.. _migration-4.3-supported-distributions: 40 41Supported distributions 42~~~~~~~~~~~~~~~~~~~~~~~ 43 44This release supports running BitBake on new GNU/Linux distributions: 45 46On the other hand, some earlier distributions are no longer supported: 47 48See :ref:`all supported distributions <system-requirements-supported-distros>`. 49 50.. _migration-4.3-go-changes: 51 52Go language changes 53~~~~~~~~~~~~~~~~~~~ 54 55- Support for the Glide package manager has been removed, as ``go mod`` 56 has become the standard. 57 58Systemd changes 59~~~~~~~~~~~~~~~ 60 61Upstream systemd is now more strict on filesystem layout and the ``usrmerge`` 62feature is therefore required alongside systemd. The Poky test configurations 63have been updated accordingly for systemd. 64 65.. _migration-4.3-recipe-changes: 66 67Recipe changes 68~~~~~~~~~~~~~~ 69 70- Runtime testing of ptest now fails if no test results are returned by 71 any given ptest. 72 73.. _migration-4.3-class-changes: 74 75Class changes 76~~~~~~~~~~~~~ 77 78- The ``perl-version`` class no longer provides the ``PERLVERSION`` and ``PERLARCH`` variables 79 as there were no users in any core layer. The functions for this functionality 80 are still available. 81 82.. _migration-4.3-removed-variables: 83 84Removed variables 85~~~~~~~~~~~~~~~~~ 86 87The following variables have been removed: 88 89- ``PERLARCH`` 90- ``PERLVERSION`` 91 92.. _migration-4.3-removed-recipes: 93 94Removed recipes 95~~~~~~~~~~~~~~~ 96 97The following recipes have been removed in this release: 98 99- ``glide``, as explained in :ref:`migration-4.3-go-changes`. 100 101.. _migration-4.3-removed-classes: 102 103Removed classes 104~~~~~~~~~~~~~~~ 105 106The following classes have been removed in this release: 107 108 109.. _migration-4.3-misc-changes: 110 111Miscellaneous changes 112~~~~~~~~~~~~~~~~~~~~~ 113 114- The ``-crosssdk`` suffix and any :term:`MLPREFIX` were removed from 115 ``virtual/XXX`` provider/dependencies where a ``PREFIX`` was used as well, 116 as we don't need both and it made automated dependency rewriting 117 unnecessarily complex. In general this only affects internal toolchain 118 dependencies so isn't end user visible. 119 120