Release 4.3 (nanbield)

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.

Supported kernel versions

The 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.

Layername override implications

Code can now know which layer a recipe is coming from through the newly added FILE_LAYERNAME variable and the layer-<layername> override. This is being used for enabling QA checks on a per layer basis. For existing code this has the side effect that the QA checks will apply to things being bbappended to recipes from other layers. Those other layers would need to have patch upstream status entries for patches being bbappended for example.

Supported distributions

This release supports running BitBake on new GNU/Linux distributions:

On the other hand, some earlier distributions are no longer supported:

See all supported distributions.

Go language changes

  • Support for the Glide package manager has been removed, as go mod has become the standard.

Systemd changes

Upstream systemd is now more strict on filesystem layout and the usrmerge feature is therefore required alongside systemd. The Poky test configurations have been updated accordingly for systemd.

Recipe changes

  • Runtime testing of ptest now fails if no test results are returned by any given ptest.

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.

Removed variables

The following variables have been removed:

  • PERLARCH

  • PERLVERSION

Removed recipes

The following recipes have been removed in this release:

Removed classes

The following classes have been removed in this release:

Miscellaneous changes

  • The -crosssdk suffix and any MLPREFIX were removed from virtual/XXX provider/dependencies where a PREFIX was used as well, as we don’t need both and it made automated dependency rewriting unnecessarily complex. In general this only affects internal toolchain dependencies so isn’t end user visible.