4.17 Moving to the Yocto Project 3.1 Release

This section provides migration information for moving to the Yocto Project 3.1 Release from the prior release.

4.17.1 Minimum system requirements

The following versions / requirements of build host components have been updated:

  • gcc 5.0

  • python 3.5

  • tar 1.28

  • rpcgen is now required on the host (part of the libc-dev-bin package on Ubuntu, Debian and related distributions, and the glibc package on RPM-based distributions).

Additionally, the makeinfo and pod2man tools are no longer required on the host.

4.17.2 mpc8315e-rdb machine removed

The MPC8315E-RDB machine is old/obsolete and unobtainable, thus given the maintenance burden the mpc8315e-rdb machine configuration that supported it has been removed in this release. The removal does leave a gap in official PowerPC reference hardware support; this may change in future if a suitable machine with accompanying support resources is found.

4.17.3 Python 2 removed

Due to the expiration of upstream support in January 2020, support for Python 2 has now been removed; it is recommended that you use Python 3 instead. If absolutely needed there is a meta-python2 community layer containing Python 2, related classes and various Python 2-based modules, however it should not be considered as supported.

4.17.4 Reproducible builds now enabled by default

In order to avoid unnecessary differences in output files (aiding binary reproducibility), the Poky distribution configuration (DISTRO = "poky") now inherits the reproducible_build class by default.

4.17.5 Impact of ptest feature is now more significant

The Poky distribution configuration (DISTRO = "poky") enables ptests by default to enable runtime testing of various components. In this release, a dependency needed to be added that has resulted in a significant increase in the number of components that will be built just when building a simple image such as core-image-minimal. If you do not need runtime tests enabled for core components, then it is recommended that you remove “ptest” from DISTRO_FEATURES to save a significant amount of build time e.g. by adding the following in your configuration:

DISTRO_FEATURES_remove = "ptest"

4.17.6 Removed recipes

The following recipes have been removed:

  • chkconfig: obsolete

  • console-tools: obsolete

  • enchant: replaced by enchant2

  • foomatic-filters: obsolete

  • libidn: no longer needed, moved to meta-oe

  • libmodulemd: replaced by libmodulemd-v1

  • linux-yocto: drop 4.19, 5.2 version recipes (5.4 now provided)

  • nspr: no longer needed, moved to meta-oe

  • nss: no longer needed, moved to meta-oe

  • python: Python 2 removed (Python 3 preferred)

  • python-setuptools: Python 2 version removed (python3-setuptools preferred)

  • sysprof: no longer needed, moved to meta-oe

  • texi2html: obsolete

  • u-boot-fw-utils: functionally replaced by libubootenv

4.17.7 features_check class replaces distro_features_check

The distro_features_check class has had its functionality expanded, now supporting ANY_OF_MACHINE_FEATURES, REQUIRED_MACHINE_FEATURES, CONFLICT_MACHINE_FEATURES, ANY_OF_COMBINED_FEATURES, REQUIRED_COMBINED_FEATURES, CONFLICT_COMBINED_FEATURES. As a result the class has now been renamed to features_check; the distro_features_check class still exists but generates a warning and redirects to the new class. In preparation for a future removal of the old class it is recommended that you update recipes currently inheriting distro_features_check to inherit features_check instead.

4.17.8 Removed classes

The following classes have been removed:

  • distutils-base: moved to meta-python2

  • distutils: moved to meta-python2

  • libc-common: merged into the glibc recipe as nothing else used it.

  • python-dir: moved to meta-python2

  • pythonnative: moved to meta-python2

  • setuptools: moved to meta-python2

  • tinderclient: dropped as it was obsolete.

4.17.9 SRC_URI checksum behaviour

Previously, recipes by tradition included both SHA256 and MD5 checksums for remotely fetched files in SRC_URI, even though only one is actually mandated. However, the MD5 checksum does not add much given its inherent weakness; thus when a checksum fails only the SHA256 sum will now be printed. The md5sum will still be verified if it is specified.

4.17.10 npm fetcher changes

The npm fetcher has been completely reworked in this release. The npm fetcher now only fetches the package source itself and no longer the dependencies; there is now also an npmsw fetcher which explicitly fetches the shrinkwrap file and the dependencies. This removes the slightly awkward NPM_LOCKDOWN and NPM_SHRINKWRAP variables which pointed to local files; the lockdown file is no longer needed at all. Additionally, the package name in npm:// entries in SRC_URI is now specified using a package parameter instead of the earlier name which overlapped with the generic name parameter. All recipes using the npm fetcher will need to be changed as a result.

An example of the new scheme:

SRC_URI = "npm://registry.npmjs.org;package=array-flatten;version=1.1.1 \

Another example where the sources are fetched from git rather than an npm repository:

SRC_URI = "git://github.com/foo/bar.git;protocol=https \

devtool and recipetool have also been updated to match with the npm fetcher changes. Other than producing working and more complete recipes for npm sources, there is also a minor change to the command line for devtool: the --fetch-dev option has been renamed to --npm-dev as it is npm-specific.

4.17.11 Packaging changes

  • intltool has been removed from packagegroup-core-sdk as it is rarely needed to build modern software - gettext can do most of the things it used to be needed for. intltool has also been removed from packagegroup-core-self-hosted as it is not needed to for standard builds.

  • git: git-am, git-difftool, git-submodule, and git-request-pull are no longer perl-based, so are now installed with the main git package instead of within git-perltools.

  • The ldconfig binary built as part of glibc has now been moved to its own ldconfig package (note no glibc- prefix). This package is in the RRECOMMENDS of the main glibc package if ldconfig is present in DISTRO_FEATURES.

  • libevent now splits each shared library into its own package (as Debian does). Since these are shared libraries and will be pulled in through the normal shared library dependency handling, there should be no impact to existing configurations other than less unnecessary libraries being installed in some cases.

  • linux-firmware now has a new package for bcm4366c and includes available NVRAM config files into the bcm43340, bcm43362, bcm43430 and bcm4356-pcie packages.

  • harfbuzz now splits the new libharfbuzz-subset.so library into its own package to reduce the main package size in cases where libharfbuzz-subset.so is not needed.

4.17.12 Additional warnings

Warnings will now be shown at do_package_qa time in the following circumstances:

  • A recipe installs .desktop files containing MimeType keys but does not inherit the new mime-xdg class

  • A recipe installs .xml files into ${datadir}/mime/packages but does not inherit the mime class

4.17.13 wic image type now used instead of live by default for x86

conf/machine/include/x86-base.inc (inherited by most x86 machine configurations) now specifies wic instead of live by default in IMAGE_FSTYPES. The live image type will likely be removed in a future release so it is recommended that you use wic instead.

4.17.14 Miscellaneous changes

  • The undocumented SRC_DISTRIBUTE_LICENSES variable has now been removed in favour of a new AVAILABLE_LICENSES variable which is dynamically set based upon license files found in ${COMMON_LICENSE_DIR} and ${LICENSE_PATH}.

  • The tune definition for big-endian microblaze machines is now microblaze instead of microblazeeb.

  • newlib no longer has built-in syscalls. libgloss should then provide the syscalls, crt0.o and other functions that are no longer part of newlib itself. If you are using TCLIBC = "newlib" this now means that you must link applications with both newlib and libgloss, whereas before newlib would run in many configurations by itself.