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[<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >

<chapter id='migration'>
<title>Migrating to a Newer Yocto Project Release</title>

    <para>
        This chapter provides information you can use to migrate work to a
        newer Yocto Project release.  You can find the same information in the
        release notes for a given release.
    </para>

<section id='moving-to-the-yocto-project-1.3-release'>
    <title>Moving to the Yocto Project 1.3 Release</title>

    <para>
        This section provides migration information for moving to the
        Yocto Project 1.3 Release from the prior release.
    </para>

    <section id='1.3-local-configuration'>
        <title>Local Configuration</title>

        <para>
            Differences include changes for
            <link linkend='var-SSTATE_MIRRORS'><filename>SSTATE_MIRRORS</filename></link>
            and <filename>bblayers.conf</filename>.
        </para>

        <section id='migration-1.3-sstate-mirrors'>
            <title>SSTATE_MIRRORS</title>

            <para>
                The shared state cache (sstate-cache), as pointed to by
                <link linkend='var-SSTATE_DIR'><filename>SSTATE_DIR</filename></link>, by default
                now has two-character subdirectories to prevent issues arising
                from too many files in the same directory.
                Also, native sstate-cache packages will go into a subdirectory named using
                the distro ID string.
                If you copy the newly structured sstate-cache to a mirror location
                (either local or remote) and then point to it in
                <link linkend='var-SSTATE_MIRRORS'><filename>SSTATE_MIRRORS</filename></link>,
                you need to append "PATH" to the end of the mirror URL so that
                the path used by BitBake before the mirror substitution is
                appended to the path used to access the mirror.
                Here is an example:
                <literallayout class='monospaced'>
     SSTATE_MIRRORS = "file://.* http://someserver.tld/share/sstate/PATH"
                </literallayout>
            </para>
        </section>

        <section id='migration-1.3-bblayers-conf'>
            <title>bblayers.conf</title>

            <para>
                The <filename>meta-yocto</filename> layer consists of two parts
                that correspond to the Poky reference distribution and the
                reference hardware Board Support Packages (BSPs), respectively:
                <filename>meta-yocto</filename> and
                <filename>meta-yocto-bsp</filename>.
                When running BitBake or Hob for the first time after upgrading,
                your <filename>conf/bblayers.conf</filename> file will be
                updated to handle this change and you will be asked to
                re-run or restart for the changes to take effect.
            </para>
        </section>
    </section>

    <section id='1.3-recipes'>
        <title>Recipes</title>

        <para>
            Differences include changes for the following:
            <itemizedlist>
                <listitem><para>Python function whitespace</para></listitem>
                <listitem><para><filename>proto=</filename> in <filename>SRC_URI</filename></para></listitem>
                <listitem><para><filename>nativesdk</filename></para></listitem>
                <listitem><para>Task recipes</para></listitem>
                <listitem><para><filename>IMAGE_FEATURES</filename></para></listitem>
                <listitem><para>Removed recipes</para></listitem>
            </itemizedlist>
        </para>

        <section id='migration-1.3-python-function-whitespace'>
            <title>Python Function Whitespace</title>

            <para>
                All Python functions must now use four spaces for indentation.
                Previously, an inconsistent mix of spaces and tabs existed,
                which made extending these functions using
                <filename>_append</filename> or <filename>_prepend</filename>
                complicated given that Python treats whitespace as
                syntactically significant.
                If you are defining or extending any Python functions (e.g.
                <filename>populate_packages</filename>, <filename>do_unpack</filename>,
                <filename>do_patch</filename> and so forth) in custom recipes
                or classes, you need to ensure you are using consistent
                four-space indentation.
            </para>
        </section>

        <section id='migration-1.3-proto=-in-src-uri'>
            <title>proto= in SRC_URI</title>

            <para>
                Any use of <filename>proto=</filename> in
                <link linkend='var-SRC_URI'><filename>SRC_URI</filename></link>
                needs to be changed to <filename>protocol=</filename>.
                In particular, this applies to the following URIs:
                <itemizedlist>
                    <listitem><para><filename>svn://</filename></para></listitem>
                    <listitem><para><filename>bzr://</filename></para></listitem>
                    <listitem><para><filename>hg://</filename></para></listitem>
                    <listitem><para><filename>osc://</filename></para></listitem>
                </itemizedlist>
                Other URIs were already using <filename>protocol=</filename>.
                This change improves consistency.
            </para>
        </section>

        <section id='migration-1.3-nativesdk'>
            <title>nativesdk</title>

            <para>
                The suffix <filename>nativesdk</filename> is now implemented
                as a prefix, which simplifies a lot of the packaging code for
                <filename>nativesdk</filename> recipes.
                All custom <filename>nativesdk</filename> recipes and any
                references need to be updated to use
                <filename>nativesdk-*</filename> instead of
                <filename>*-nativesdk</filename>.
            </para>
        </section>

        <section id='migration-1.3-task-recipes'>
            <title>Task Recipes</title>

            <para>
                "Task" recipes are now known as "Package groups" and have
                been renamed from <filename>task-*.bb</filename> to
                <filename>packagegroup-*.bb</filename>.
                Existing references to the previous <filename>task-*</filename>
                names should work in most cases as there is an automatic
                upgrade path for most packages.
                However, you should update references in your own recipes and
                configurations as they could be removed in future releases.
                You should also rename any custom <filename>task-*</filename>
                recipes to <filename>packagegroup-*</filename>, and change
                them to inherit <filename>packagegroup</filename> instead of
                <filename>task</filename>, as well as taking the opportunity
                to remove anything now handled by
                <filename>packagegroup.bbclass</filename>, such as providing
                <filename>-dev</filename> and <filename>-dbg</filename>
                packages, setting
                <link linkend='var-LIC_FILES_CHKSUM'><filename>LIC_FILES_CHKSUM</filename></link>,
                and so forth.
                See the
                "<link linkend='ref-classes-packagegroup'><filename>packagegroup.bbclass</filename></link>"
                section for further details.
            </para>
        </section>

        <section id='migration-1.3-image-features'>
            <title>IMAGE_FEATURES</title>

            <para>
                Image recipes that previously included "apps-console-core"
                in <link linkend='var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></link>
                should now include "splash" instead to enable the boot-up
                splash screen.
                Retaining "apps-console-core" will still include the splash
                screen but generates a warning.
                The "apps-x11-core" and "apps-x11-games"
                <filename>IMAGE_FEATURES</filename> features have been removed.
            </para>
        </section>

        <section id='migration-1.3-removed-recipes'>
            <title>Removed Recipes</title>

            <para>
                The following recipes have been removed.
                For most of them, it is unlikely that you would have any
                references to them in your own
                <ulink url='&YOCTO_DOCS_DEV_URL;#metadata'>Metadata</ulink>.
                However, you should check your metadata against this list to be sure:
                <itemizedlist>
                    <listitem><para><emphasis><filename>libx11-trim</filename></emphasis>:
                        Replaced by <filename>libx11</filename>, which has a negligible
                        size difference with modern Xorg.</para></listitem>
                    <listitem><para><emphasis><filename>xserver-xorg-lite</filename></emphasis>:
                        Use <filename>xserver-xorg</filename>, which has a negligible
                        size difference when DRI and GLX modules are not installed.</para></listitem>
                    <listitem><para><emphasis><filename>xserver-kdrive</filename></emphasis>:
                        Effectively unmaintained for many years.</para></listitem>
                    <listitem><para><emphasis><filename>mesa-xlib</filename></emphasis>:
                        No longer serves any purpose.</para></listitem>
                    <listitem><para><emphasis><filename>galago</filename></emphasis>:
                        Replaced by telepathy.</para></listitem>
                    <listitem><para><emphasis><filename>gail</filename></emphasis>:
                        Functionality was integrated into GTK+ 2.13.</para></listitem>
                    <listitem><para><emphasis><filename>eggdbus</filename></emphasis>:
                        No longer needed.</para></listitem>
                    <listitem><para><emphasis><filename>gcc-*-intermediate</filename></emphasis>:
                        The build has been restructured to avoid the need for
                        this step.</para></listitem>
                    <listitem><para><emphasis><filename>libgsmd</filename></emphasis>:
                        Unmaintained for many years.
                        Functionality now provided by
                        <filename>ofono</filename> instead.</para></listitem>
                    <listitem><para><emphasis>contacts, dates, tasks, eds-tools</emphasis>:
                        Largely unmaintained PIM application suite.
                        It has been moved to <filename>meta-gnome</filename>
                        in <filename>meta-openembedded</filename>.</para></listitem>
                </itemizedlist>
                In addition to the previously listed changes, the
                <filename>meta-demoapps</filename> directory has also been removed
                because the recipes in it were not being maintained and many
                had become obsolete or broken.
                Additionally, these recipes were not parsed in the default configuration.
                Many of these recipes are already provided in an updated and
                maintained form within the OpenEmbedded community layers such as
                <filename>meta-oe</filename> and <filename>meta-gnome</filename>.
                For the remainder, you can now find them in the
                <filename>meta-extras</filename> repository, which is in the
                Yocto Project
                <ulink url='&YOCTO_DOCS_DEV_URL;#source-repositories'>Source Repositories</ulink>.
            </para>
        </section>
    </section>

    <section id='1.3-linux-kernel-naming'>
        <title>Linux Kernel Naming</title>

        <para>
            The naming scheme for kernel output binaries has been changed to
            now include
            <link linkend='var-PE'><filename>PE</filename></link> as part of the
            filename:
            <literallayout class='monospaced'>
     KERNEL_IMAGE_BASE_NAME ?= "${KERNEL_IMAGETYPE}-${PE}-${PV}-${PR}-${MACHINE}-${DATETIME}"
            </literallayout>
        </para>

        <para>
            Because the <filename>PE</filename> variable is not set by default,
            these binary files could result with names that include two dash
            characters.
            Here is an example:
            <literallayout class='monospaced'>
     bzImage--3.10.9+git0+cd502a8814_7144bcc4b8-r0-qemux86-64-20130830085431.bin
            </literallayout>
        </para>
    </section>
</section>

<section id='moving-to-the-yocto-project-1.4-release'>
    <title>Moving to the Yocto Project 1.4 Release</title>

    <para>
        This section provides migration information for moving to the
        Yocto Project 1.4 Release from the prior release.
    </para>

    <section id='migration-1.4-bitbake'>
        <title>BitBake</title>

        <para>
            Differences include the following:
            <itemizedlist>
                <listitem><para><emphasis>Comment Continuation:</emphasis>
                    If a comment ends with a line continuation (\) character,
                    then the next line must also be a comment.
                    Any instance where this is not the case, now triggers
                    a warning.
                    You must either remove the continuation character, or be
                    sure the next line is a comment.
                    </para></listitem>
                <listitem><para><emphasis>Package Name Overrides:</emphasis>
                    The runtime package specific variables
                    <link linkend='var-RDEPENDS'><filename>RDEPENDS</filename></link>,
                    <link linkend='var-RRECOMMENDS'><filename>RRECOMMENDS</filename></link>,
                    <link linkend='var-RSUGGESTS'><filename>RSUGGESTS</filename></link>,
                    <link linkend='var-RPROVIDES'><filename>RPROVIDES</filename></link>,
                    <link linkend='var-RCONFLICTS'><filename>RCONFLICTS</filename></link>,
                    <link linkend='var-RREPLACES'><filename>RREPLACES</filename></link>,
                    <link linkend='var-FILES'><filename>FILES</filename></link>,
                    <link linkend='var-ALLOW_EMPTY'><filename>ALLOW_EMPTY</filename></link>,
                    and the pre, post, install, and uninstall script functions
                    <filename>pkg_preinst</filename>,
                    <filename>pkg_postinst</filename>,
                    <filename>pkg_prerm</filename>, and
                    <filename>pkg_postrm</filename> should always have a
                    package name override.
                    For example, use <filename>RDEPENDS_${PN}</filename> for
                    the main package instead of <filename>RDEPENDS</filename>.
                    BitBake uses more strict checks when it parses recipes.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.4-build-behavior'>
        <title>Build Behavior</title>

        <para>
            Differences include the following:
            <itemizedlist>
                <listitem><para><emphasis>Shared State Code:</emphasis>
                    The shared state code has been optimized to avoid running
                    unnecessary tasks.
                    For example,
                    <filename>bitbake -c rootfs some-image</filename> from
                    shared state no longer populates the target sysroot
                    since that is not necessary.
                    Instead, the system just needs to extract the output
                    package contents, re-create the packages, and construct
                    the root filesystem.
                    This change is unlikely to cause any problems unless
                    you have missing declared dependencies.
                    </para></listitem>
                <listitem><para><emphasis>Scanning Directory Names:</emphasis>
                    When scanning for files in
                    <link linkend='var-SRC_URI'><filename>SRC_URI</filename></link>,
                    the build system now uses
                    <link linkend='var-FILESOVERRIDES'><filename>FILESOVERRIDES</filename></link>
                    instead of <link linkend='var-OVERRIDES'><filename>OVERRIDES</filename></link>
                    for the directory names.
                    In general, the values previously in
                    <filename>OVERRIDES</filename> are now in
                    <filename>FILESOVERRIDES</filename> as well.
                    However, if you relied upon an additional value
                    you previously added to <filename>OVERRIDES</filename>,
                    you might now need to add it to
                    <filename>FILESOVERRIDES</filename> unless you are already
                    adding it through the
                    <link linkend='var-MACHINEOVERRIDES'><filename>MACHINEOVERRIDES</filename></link>
                    or <link linkend='var-DISTROOVERRIDES'><filename>DISTROOVERRIDES</filename></link>
                    variables, as appropriate.
                    For more related changes, see the
                    "<link linkend='migration-1.4-variables'>Variables</link>"
                    section.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>


    <section id='migration-1.4-proxies-and-fetching-source'>
        <title>Proxies and Fetching Source</title>

        <para>
            A new <filename>oe-git-proxy</filename> script has been added to
            replace previous methods of handling proxies and fetching source
            from Git.
            See the <filename>meta-yocto/conf/site.conf.sample</filename> file
            for information on how to use this script.
        </para>
    </section>

    <section id='migration-1.4-custom-interfaces-file-netbase-change'>
        <title>Custom Interfaces File (netbase change)</title>

        <para>
            If you have created your own custom
            <filename>etc/network/interfaces</filename> file by creating
            an append file for the <filename>netbase</filename> recipe,
            you now need to create an append file for the
            <filename>init-ifupdown</filename> recipe instead, which you can
            find in the
            <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>
            at <filename>meta/recipes-core/init-ifupdown</filename>.
            For information on how to use append files, see the
            "<ulink url='&YOCTO_DOCS_DEV_URL;#using-bbappend-files'>Using .bbappend Files</ulink>"
            in the Yocto Project Development Manual.
        </para>
    </section>

    <section id='migration-1.4-remote-debugging'>
        <title>Remote Debugging</title>

        <para>
            Support for remote debugging with the Eclipse IDE is now
            separated into an image feature
            (<filename>eclipse-debug</filename>) that corresponds to the
            <filename>packagegroup-core-eclipse-debug</filename> package group.
            Previously, the debugging feature was included through the
            <filename>tools-debug</filename> image feature, which corresponds
            to the <filename>packagegroup-core-tools-debug</filename>
            package group.
        </para>
    </section>

    <section id='migration-1.4-variables'>
        <title>Variables</title>

        <para>
            The following variables have changed:
            <itemizedlist>
                <listitem><para><emphasis><filename>SANITY_TESTED_DISTROS</filename>:</emphasis>
                    This variable now uses a distribution ID, which is composed
                    of the host distributor ID followed by the release.
                    Previously,
                    <link linkend='var-SANITY_TESTED_DISTROS'><filename>SANITY_TESTED_DISTROS</filename></link>
                    was composed of the description field.
                    For example, "Ubuntu 12.10" becomes "Ubuntu-12.10".
                    You do not need to worry about this change if you are not
                    specifically setting this variable, or if you are
                    specifically setting it to "".
                    </para></listitem>
                <listitem><para><emphasis><filename>SRC_URI</filename>:</emphasis>
                    The <filename>${</filename><link linkend='var-PN'><filename>PN</filename></link><filename>}</filename>,
                    <filename>${</filename><link linkend='var-PF'><filename>PF</filename></link><filename>}</filename>,
                    <filename>${</filename><link linkend='var-P'><filename>P</filename></link><filename>}</filename>,
                    and <filename>FILE_DIRNAME</filename> directories have been
                    dropped from the default value of the
                    <link linkend='var-FILESPATH'><filename>FILESPATH</filename></link>
                    variable, which is used as the search path for finding files
                    referred to in
                    <link linkend='var-SRC_URI'><filename>SRC_URI</filename></link>.
                    If you have a recipe that relied upon these directories,
                    which would be unusual, then you will need to add the
                    appropriate paths within the recipe or, alternatively,
                    rearrange the files.
                    The most common locations are still covered by
                    <filename>${BP}</filename>, <filename>${BPN}</filename>,
                    and "files", which all remain in the default value of
                    <link linkend='var-FILESPATH'><filename>FILESPATH</filename></link>.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-target-package-management-with-rpm'>
        <title>Target Package Management with RPM</title>

        <para>
            If runtime package management is enabled and the RPM backend
            is selected, Smart is now installed for package download, dependency
            resolution, and upgrades instead of Zypper.
            For more information on how to use Smart, run the following command
            on the target:
            <literallayout class='monospaced'>
     smart --help
            </literallayout>
        </para>
    </section>

    <section id='migration-1.4-recipes-moved'>
        <title>Recipes Moved</title>

        <para>
            The following recipes were moved from their previous locations
            because they are no longer used by anything in
            the OpenEmbedded-Core:
            <itemizedlist>
                <listitem><para><emphasis><filename>clutter-box2d</filename>:</emphasis>
                    Now resides in the <filename>meta-oe</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>evolution-data-server</filename>:</emphasis>
                    Now resides in the <filename>meta-gnome</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>gthumb</filename>:</emphasis>
                    Now resides in the <filename>meta-gnome</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>gtkhtml2</filename>:</emphasis>
                    Now resides in the <filename>meta-oe</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>gupnp</filename>:</emphasis>
                    Now resides in the <filename>meta-multimedia</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>gypsy</filename>:</emphasis>
                    Now resides in the <filename>meta-oe</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>libcanberra</filename>:</emphasis>
                    Now resides in the <filename>meta-gnome</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>libgdata</filename>:</emphasis>
                    Now resides in the <filename>meta-gnome</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>libmusicbrainz</filename>:</emphasis>
                    Now resides in the <filename>meta-multimedia</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>metacity</filename>:</emphasis>
                    Now resides in the <filename>meta-gnome</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>polkit</filename>:</emphasis>
                    Now resides in the <filename>meta-oe</filename> layer.
                    </para></listitem>
                <listitem><para><emphasis><filename>zeroconf</filename>:</emphasis>
                    Now resides in the <filename>meta-networking</filename> layer.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.4-removals-and-renames'>
        <title>Removals and Renames</title>

        <para>
            The following list shows what has been removed or renamed:
            <itemizedlist>
                <listitem><para><emphasis><filename>evieext</filename>:</emphasis>
                    Removed because it has been removed from
                    <filename>xserver</filename> since 2008.
                    </para></listitem>
                <listitem><para><emphasis>Gtk+ DirectFB:</emphasis>
                    Removed support because upstream Gtk+ no longer supports it
                    as of version 2.18.
                    </para></listitem>
                <listitem><para><emphasis><filename>libxfontcache / xfontcacheproto</filename>:</emphasis>
                    Removed because they were removed from the Xorg server in 2008.
                    </para></listitem>
                <listitem><para><emphasis><filename>libxp / libxprintapputil / libxprintutil / printproto</filename>:</emphasis>
                    Removed because the XPrint server was removed from
                    Xorg in 2008.
                    </para></listitem>
                <listitem><para><emphasis><filename>libxtrap / xtrapproto</filename>:</emphasis>
                    Removed because their functionality was broken upstream.
                    </para></listitem>
                <listitem><para><emphasis>linux-yocto 3.0 kernel:</emphasis>
                    Removed with linux-yocto 3.8 kernel being added.
                    The linux-yocto 3.2 and linux-yocto 3.4 kernels remain
                    as part of the release.
                    </para></listitem>
                <listitem><para><emphasis><filename>lsbsetup</filename>:</emphasis>
                    Removed with functionality now provided by
                    <filename>lsbtest</filename>.
                    </para></listitem>
                <listitem><para><emphasis><filename>matchbox-stroke</filename>:</emphasis>
                    Removed because it was never more than a proof-of-concept.
                    </para></listitem>
                <listitem><para><emphasis><filename>matchbox-wm-2 / matchbox-theme-sato-2</filename>:</emphasis>
                    Removed because they are not maintained.
                    However, <filename>matchbox-wm</filename> and
                    <filename>matchbox-theme-sato</filename> are still
                    provided.
                    </para></listitem>
                <listitem><para><emphasis><filename>mesa-dri</filename>:</emphasis>
                    Renamed to <filename>mesa</filename>.
                    </para></listitem>
                <listitem><para><emphasis><filename>mesa-xlib</filename>:</emphasis>
                    Removed because it was no longer useful.
                    </para></listitem>
                <listitem><para><emphasis><filename>mutter</filename>:</emphasis>
                    Removed because nothing ever uses it and the recipe is
                    very old.
                    </para></listitem>
                <listitem><para><emphasis><filename>orinoco-conf</filename>:</emphasis>
                    Removed because it has become obsolete.
                    </para></listitem>
                <listitem><para><emphasis><filename>update-modules</filename>:</emphasis>
                    Removed because it is no longer used.
                    The kernel module <filename>postinstall</filename> and
                    <filename>postrm</filename> scripts can now do the same
                    task without the use of this script.
                    </para></listitem>
                <listitem><para><emphasis><filename>web</filename>:</emphasis>
                    Removed because it is not maintained.  Superseded by
                    <filename>web-webkit</filename>.
                    </para></listitem>
                <listitem><para><emphasis><filename>xf86bigfontproto</filename>:</emphasis>
                    Removed because upstream it has been disabled by default
                    since 2007.
                    Nothing uses <filename>xf86bigfontproto</filename>.
                    </para></listitem>
                <listitem><para><emphasis><filename>xf86rushproto</filename>:</emphasis>
                    Removed because its dependency in
                    <filename>xserver</filename> was spurious and it was
                    removed in 2005.
                    </para></listitem>
                <listitem><para><emphasis><filename>zypper / libzypp / sat-solver</filename>:</emphasis>
                    Removed and been functionally replaced with Smart
                    (<filename>python-smartpm</filename>) when RPM packaging
                    is used and package management is enabled on the target.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>
</section>

<section id='moving-to-the-yocto-project-1.5-release'>
    <title>Moving to the Yocto Project 1.5 Release</title>

    <para>
        This section provides migration information for moving to the
        Yocto Project 1.5 Release from the prior release.
    </para>

    <section id='migration-1.5-host-dependency-changes'>
        <title>Host Dependency Changes</title>

        <para>
            The OpenEmbedded build system now has some additional requirements
            on the host system:
            <itemizedlist>
                <listitem><para>Python 2.7.3+</para></listitem>
                <listitem><para>Tar 1.24+</para></listitem>
                <listitem><para>Git 1.7.5+</para></listitem>
                <listitem><para>Patched version of Make if you are using
                    3.82.
                    Most distributions that provide Make 3.82 use the patched
                    version.</para></listitem>
            </itemizedlist>
            If the Linux distribution you are using on your build host
            does not provide packages for these, you can install and use
            the Buildtools tarball, which provides an SDK-like environment
            containing them.
        </para>

        <para>
            For more information on this requirement, see the
            "<link linkend='required-git-tar-and-python-versions'>Required Git, tar, and Python Versions</link>"
            section.
        </para>
    </section>

    <section id='migration-1.5-atom-pc-bsp'>
        <title><filename>atom-pc</filename> Board Support Package (BSP)</title>

        <para>
            The <filename>atom-pc</filename> hardware reference BSP has been
            replaced by a <filename>genericx86</filename> BSP.
            This BSP is not necessarily guaranteed to work on all x86
            hardware, but it will run on a wider range of systems than the
            <filename>atom-pc</filename> did.
            <note>
                Additionally, a <filename>genericx86-64</filename> BSP has been
                added for 64-bit systems.
            </note>
        </para>
    </section>

    <section id='migration-1.5-bitbake'>
        <title>BitBake</title>

        <para>
            The following changes have been made that relate to BitBake:
            <itemizedlist>
                <listitem><para>
                    BitBake now supports a <filename>_remove</filename>
                    operator.
                    The addition of this operator means you will have to
                    rename any items in recipe space (functions, variables)
                    whose names currently contain
                    <filename>_remove_</filename> or end with
                    <filename>_remove</filename> to avoid unexpected behavior.
                    </para></listitem>
                <listitem><para>
                    BitBake's global method pool has been removed.
                    This method is not particularly useful and led to clashes
                    between recipes containing functions that had the
                    same name.</para></listitem>
                <listitem><para>
                    The "none" server backend has been removed.
                    The "process" server backend has been serving well as the
                    default for a long time now.</para></listitem>
                <listitem><para>
                    The <filename>bitbake-runtask</filename> script has been
                    removed.</para></listitem>
                <listitem><para>
                    <filename>${</filename><link linkend='var-P'><filename>P</filename></link><filename>}</filename>
                    and
                    <filename>${</filename><link linkend='var-PF'><filename>PF</filename></link><filename>}</filename>
                    are no longer added to
                    <link linkend='var-PROVIDES'><filename>PROVIDES</filename></link>
                    by default in <filename>bitbake.conf</filename>.
                    These version-specific <filename>PROVIDES</filename>
                    items were seldom used.
                    Attempting to use them could result in two versions being
                    built simultaneously rather than just one version due to
                    the way BitBake resolves dependencies.</para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.5-qa-warnings'>
        <title>QA Warnings</title>

        <para>
            The following changes have been made to the package QA checks:
            <itemizedlist>
                <listitem><para>
                    If you have customized
                    <link linkend='var-ERROR_QA'><filename>ERROR_QA</filename></link>
                    or <link linkend='var-WARN_QA'><filename>WARN_QA</filename></link>
                    values in your configuration, check that they contain all of
                    the issues that you wish to be reported.
                    Previous Yocto Project versions contained a bug that meant
                    that any item not mentioned in <filename>ERROR_QA</filename>
                    or <filename>WARN_QA</filename> would be treated as a
                    warning.
                    Consequently, several important items were not already in
                    the default value of <filename>WARN_QA</filename>.
                    All of the possible QA checks are now documented in the
                    "<link linkend='ref-classes-insane'><filename>insane.bbclass</filename></link>"
                    section.</para></listitem>
                <listitem><para>
                    An additional QA check has been added to check if
                    <filename>/usr/share/info/dir</filename> is being installed.
                    Your recipe should delete this file within
                    <filename>do_install</filename> if "make install" is
                    installing it.</para></listitem>
                <listitem><para>
                    If you are using the buildhistory class, the check for the
                    package version going backwards is now controlled using a
                    standard QA check.
                    Thus, if you have customized your
                    <filename>ERROR_QA</filename> or
                    <filename>WARN_QA</filename> values and still wish to have
                    this check performed, you should add
                    "version-going-backwards" to your value for one or the
                    other variables depending on how you wish it to be handled.
                    See the documented QA checks in the
                    "<link linkend='ref-classes-insane'><filename>insane.bbclass</filename></link>"
                    section.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.5-directory-layout-changes'>
        <title>Directory Layout Changes</title>

        <para>
            The following directory changes exist:
            <itemizedlist>
                <listitem><para>
                    Output SDK installer files are now named to include the
                    image name and tuning architecture through the
                    <link linkend='var-SDK_NAME'><filename>SDK_NAME</filename></link>
                    variable.</para></listitem>
                <listitem><para>
                    Images and related files are now installed into a directory
                    that is specific to the machine, instead of a parent
                    directory containing output files for multiple machines.
                    The
                    <link linkend='var-DEPLOY_DIR_IMAGE'><filename>DEPLOY_DIR_IMAGE</filename></link>
                    variable continues to point to the directory containing
                    images for the current
                    <link linkend='var-MACHINE'><filename>MACHINE</filename></link>
                    and should be used anywhere there is a need to refer to
                    this directory.
                    The <filename>runqemu</filename> script now uses this
                    variable to find images and kernel binaries and will use
                    BitBake to determine the directory.
                    Alternatively, you can set the
                    <filename>DEPLOY_DIR_IMAGE</filename> variable in the
                    external environment.</para></listitem>
                <listitem><para>
                    When buildhistory is enabled, its output is now written
                    under the
                    <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink>
                    rather than
                    <link linkend='var-TMPDIR'><filename>TMPDIR</filename></link>.
                    Doing so makes it easier to delete
                    <filename>TMPDIR</filename> and preserve the build history.
                    Additionally, data for produced SDKs is now split by
                    <link linkend='var-IMAGE_NAME'><filename>IMAGE_NAME</filename></link>.
                    </para></listitem>
                <listitem><para>
                    The <filename>pkgdata</filename> directory produced as
                    part of the packaging process has been collapsed into a
                    single machine-specific directory.
                    This directory is located under
                    <filename>sysroots</filename> and uses a machine-specific
                    name (i.e.
                    <filename>tmp/sysroots/&lt;machine&gt;/pkgdata</filename>).
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.5-shortened-git-srcrev-values'>
        <title>Shortened Git <filename>SRCREV</filename> Values</title>

        <para>
            BitBake will now shorten revisions from Git repositories from the
            normal 40 characters down to 10 characters within
            <link linkend='var-SRCPV'><filename>SRCPV</filename></link>
            for improved usability in path and file names.
            This change should be safe within contexts where these revisions
            are used because the chances of spatially close collisions
            is very low.
            Distant collisions are not a major issue in the way
            the values are used.
        </para>
    </section>

    <section id='migration-1.5-image-features'>
        <title><filename>IMAGE_FEATURES</filename></title>

        <para>
            The following changes have been made that relate to
            <link linkend='var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></link>:
            <itemizedlist>
                <listitem><para>
                    The value of
                    <link linkend='var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></link>
                    is now validated to ensure invalid feature items are not
                    added.
                    Some users mistakenly add package names to this variable
                    instead of using
                    <link linkend='var-IMAGE_INSTALL'><filename>IMAGE_INSTALL</filename></link>
                    in order to have the package added to the image, which does
                    not work.
                    This change is intended to catch those kinds of situations.
                    Valid <filename>IMAGE_FEATURES</filename> are drawn from
                    <link linkend='var-PACKAGE_GROUP'><filename>PACKAGE_GROUP</filename></link>
                    definitions,
                    <link linkend='var-COMPLEMENTARY_GLOB'><filename>COMPLEMENTARY_GLOB</filename></link>
                    and a new "validitems" varflag on
                    <filename>IMAGE_FEATURES</filename>.
                    The "validitems" varflag change allows additional features
                    to be added if they are not provided using the previous
                    two mechanisms.
                    </para></listitem>
                <listitem><para>
                    The previously deprecated "apps-console-core"
                    <filename>IMAGE_FEATURES</filename> item is no longer
                    supported.
                    Add "splash" to <filename>IMAGE_FEATURES</filename> if you
                    wish to have the splash screen enabled, since this is
                    all that apps-console-core was doing.</para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.5-run'>
        <title><filename>run</filename></title>

        <para>
            The <filename>run</filename> directory from the Filesystem
            Hierarchy Standard 3.0 has been introduced.
            You can find some of the implications for this change
            <ulink url='http://cgit.openembedded.org/openembedded-core/commit/?id=0e326280a15b0f2c4ef2ef4ec441f63f55b75873'>here</ulink>.
            The change also means that recipes that install files to
            <filename>/var/run</filename> must be changed.
            You can find a guide on how to make these changes
            <ulink url='http://permalink.gmane.org/gmane.comp.handhelds.openembedded/58530'>here</ulink>.
        </para>
    </section>

    <section id='migration-1.5-removal-of-package-manager-database-within-image-recipes'>
        <title>Removal of Package Manager Database Within Image Recipes</title>

        <para>
            The image <filename>core-image-minimal</filename> no longer adds
            <filename>remove_packaging_data_files</filename> to
            <link linkend='var-ROOTFS_POSTPROCESS_COMMAND'><filename>ROOTFS_POSTPROCESS_COMMAND</filename></link>.
            This addition is now handled automatically when "package-management"
            is not in
            <link linkend='var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></link>.
            If you have custom image recipes that make this addition,
            you should remove the lines, as they are not needed and might
            interfere with correct operation of postinstall scripts.
        </para>
    </section>

    <section id='migration-1.5-images-now-rebuild-only-on-changes-instead-of-every-time'>
        <title>Images Now Rebuild Only on Changes Instead of Every Time</title>

        <para>
            The <filename>do_rootfs</filename> and other related image
            construction tasks are no longer marked as "nostamp".
            Consequently, they will only be re-executed when their inputs have
            changed.
            Previous versions of the OpenEmbedded build system always rebuilt
            the image when requested rather when necessary.
        </para>
    </section>

    <section id='migration-1.5-task-recipes'>
        <title>Task Recipes</title>

        <para>
            The previously deprecated <filename>task.bbclass</filename> has
            now been dropped.
            For recipes that previously inherited from this task, you should
            rename them from <filename>task-*</filename> to
            <filename>packagegroup-*</filename> and inherit packagegroup
            instead.
        </para>

        <para>
            For more information, see the
            "<link linkend='ref-classes-packagegroup'><filename>packagegroup.bbclass</filename></link>"
            section.
        </para>
    </section>

    <section id='migration-1.5-busybox'>
        <title>BusyBox</title>

        <para>
            By default, we now split BusyBox into two binaries:
            one that is suid root for those components that need it, and
            another for the rest of the components.
            Splitting BusyBox allows for optimization that eliminates the
            <filename>tinylogin</filename> recipe as recommended by upstream.
            You can disable this split by setting
            <link linkend='var-BUSYBOX_SPLIT_SUID'><filename>BUSYBOX_SPLIT_SUID</filename></link>
            to "0".
        </para>
    </section>

    <section id='migration-1.5-automated-image-testing'>
        <title>Automated Image Testing</title>

        <para>
            A new automated image testing framework has been added
            through the
            <link linkend='ref-classes-testimage'><filename>testimage*.bbclass</filename></link>
            class.
            This framework replaces the older
            <filename>imagetest-qemu</filename> framework.
        </para>

        <para>
            You can learn more about performing automated image tests in the
            "<ulink url='&YOCTO_DOCS_DEV_URL;#performing-automated-runtime-testing'>Performing Automated Runtime Testing</ulink>"
            section.
        </para>
    </section>

    <section id='migration-1.5-build-history'>
        <title>Build History</title>

        <para>
            Following are changes to Build History:
            <itemizedlist>
                <listitem><para>
                     Installed package sizes:
                     <filename>installed-package-sizes.txt</filename> for an
                     image now records the size of the files installed by each
                     package instead of the size of each compressed package
                     archive file.</para></listitem>
                <listitem><para>
                    The dependency graphs (<filename>depends*.dot</filename>)
                    now use the actual package names instead of replacing
                    dashes, dots and plus signs with underscores.
                    </para></listitem>
                <listitem><para>
                    The <filename>buildhistory-diff</filename> and
                    <filename>buildhistory-collect-srcrevs</filename>
                    utilities have improved command-line handling.
                    Use the <filename>&dash;&dash;help</filename> option for
                    each utility for more information on the new syntax.
                    </para></listitem>
            </itemizedlist>
            For more information on Build History, see the
            "<link linkend='maintaining-build-output-quality'>Maintaining Build Output Quality</link>"
            section.
        </para>
    </section>

    <section id='migration-1.5-udev'>
        <title><filename>udev</filename></title>

        <para>
            Following are changes to <filename>udev</filename>:
            <itemizedlist>
                <listitem><para>
                    <filename>udev</filename> no longer brings in
                    <filename>udev-extraconf</filename> automatically
                    through
                    <link linkend='var-RRECOMMENDS'><filename>RRECOMMENDS</filename></link>,
                    since this was originally intended to be optional.
                    If you need the extra rules, then add
                    <filename>udev-extraconf</filename> to your image.
                    </para></listitem>
                <listitem><para>
                    <filename>udev</filename> no longer brings in
                    <filename>pciutils-ids</filename> or
                    <filename>usbutils-ids</filename> through
                    <filename>RRECOMMENDS</filename>.
                    These are not needed by <filename>udev</filename> itself
                    and removing them saves around 350KB.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.5-removed-renamed-recipes'>
        <title>Removed and Renamed Recipes</title>

        <itemizedlist>
            <listitem><para>
                The <filename>linux-yocto</filename> 3.2 kernel has been
                removed.</para></listitem>
            <listitem><para>
                <filename>libtool-nativesdk</filename> has been renamed to
                <filename>nativesdk-libtool</filename>.</para></listitem>
            <listitem><para>
                <filename>tinylogin</filename> has been removed.
                It has been replaced by a suid portion of Busybox.
                See the
                "<link linkend='migration-1.5-busybox'>BusyBox</link>" section
                for more information.</para></listitem>
            <listitem><para>
                <filename>external-python-tarball</filename> has been renamed
                to <filename>buildtools-tarball</filename>.
                </para></listitem>
            <listitem><para>
                <filename>web-webkit</filename> has been removed.
                It has been functionally replaced by
                <filename>midori</filename>.</para></listitem>
            <listitem><para>
                <filename>imake</filename> has been removed.
                It is no longer needed by any other recipe.
                </para></listitem>
            <listitem><para>
                <filename>transfig-native</filename> has been removed.
                It is no longer needed by any other recipe.
                </para></listitem>
            <listitem><para>
                <filename>anjuta-remote-run</filename> has been removed.
                Anjuta IDE integration has not been officially supported for
                several releases.</para></listitem>
        </itemizedlist>
    </section>

    <section id='migration-1.5-other-changes'>
        <title>Other Changes</title>

        <para>
            Following is a list of short entries describing other changes:
            <itemizedlist>
                <listitem><para>
                    <filename>run-postinsts</filename>: Make this generic.
                    </para></listitem>
                <listitem><para>
                    <filename>base-files</filename>: Remove the unnecessary
                    <filename>media/xxx</filename> directories.
                    </para></listitem>
                <listitem><para>
                    <filename>alsa-state</filename>: Provide an empty
                    <filename>asound.conf</filename> by default.
                    </para></listitem>
                <listitem><para>
                    <filename>classes/image</filename>: Ensure
                    <link linkend='var-BAD_RECOMMENDATIONS'><filename>BAD_RECOMMENDATIONS</filename></link>
                    supports pre-renamed package names.</para></listitem>
                <listitem><para>
                    <filename>classes/rootfs_rpm</filename>: Implement
                    <link linkend='var-BAD_RECOMMENDATIONS'><filename>BAD_RECOMMENDATIONS</filename></link>
                    for RPM.</para></listitem>
                <listitem><para>
                    <filename>systemd</filename>: Remove
                    <filename>systemd_unitdir</filename> if
                    <filename>systemd</filename> is not in
                    <link linkend='var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></link>.
                    </para></listitem>
                <listitem><para>
                    <filename>systemd</filename>: Remove
                    <filename>init.d</filename> dir if
                    <filename>systemd</filename> unit file is present and
                    <filename>sysvinit</filename> is not a distro feature.
                    </para></listitem>
                <listitem><para>
                    <filename>libpam</filename>: Deny all services for the
                    <filename>OTHER</filename> entries.
                    </para></listitem>
                <listitem><para>
                    <filename>image.bbclass</filename>: Move
                    <filename>runtime_mapping_rename</filename> to avoid
                    conflict with <filename>multilib</filename>.
                    See
                    <ulink url='https://bugzilla.yoctoproject.org/show_bug.cgi?id=4993'><filename>YOCTO #4993</filename></ulink>
                    in Bugzilla for more information.
                    </para></listitem>
                <listitem><para>
                    <filename>linux-dtb</filename>: Use kernel build system
                    to generate the <filename>dtb</filename> files.
                    </para></listitem>
                <listitem><para>
                    <filename>kern-tools</filename>: Switch from guilt to
                    new <filename>kgit-s2q</filename> tool.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>
</section>

<section id='moving-to-the-yocto-project-1.6-release'>
    <title>Moving to the Yocto Project 1.6 Release</title>

    <para>
        This section provides migration information for moving to the
        Yocto Project 1.6 Release from the prior release.
    </para>


    <section id='migration-1.6-archiver-class'>
        <title><filename>archiver</filename> Class</title>

        <para>
            The
            <link linkend='ref-classes-archiver'><filename>archiver</filename></link>
            class has been rewritten and its configuration has been simplified.
            For more details on the source archiver, see the
            "<ulink url='&YOCTO_DOCS_DEV_URL;#maintaining-open-source-license-compliance-during-your-products-lifecycle'>Maintaining Open Source License Compliance During Your Product's Lifecycle</ulink>"
            section in the Yocto Project Development Manual.
        </para>
    </section>

    <section id='migration-1.6-packaging-changes'>
        <title>Packaging Changes</title>

        <para>
            The following packaging changes have been made:
            <itemizedlist>
                <listitem><para>
                    The <filename>binutils</filename> recipe no longer produces
                    a <filename>binutils-symlinks</filename> package.
                    <filename>update-alternatives</filename> is now used to
                    handle the preferred <filename>binutils</filename>
                    variant on the target instead.
                    </para></listitem>
                <listitem><para>
                    The tc (traffic control) utilities have been split out of
                    the main <filename>iproute2</filename> package and put
                    into the <filename>iproute2-tc</filename> package.
                    </para></listitem>
                <listitem><para>
                    The <filename>gtk-engines</filename> schemas have been
                    moved to a dedicated
                    <filename>gtk-engines-schemas</filename> package.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.6-bitbake'>
        <title>BitBake</title>

        <para>
            The following changes have been made to
            <ulink url='&YOCTO_DOCS_DEV_URL;#bitbake-term'>BitBake</ulink>.
        </para>

        <section id='migration-1.6-bitbake-deps'>
            <title>Python Definition substitutions</title>

            <para>
                BitBake had some previously deprecated Python definitions
                within its <filename>bb</filename> module removed.
                You should use their sub-module counterparts instead:
                <itemizedlist>
                    <listitem><para><filename>bb.MalformedUrl</filename>:
                        Use <filename>bb.fetch.MalformedUrl</filename>.
                        </para></listitem>
                    <listitem><para><filename>bb.fetch.encodeurl</filename>:
                        Use <filename>bb.fetch.encodeurl</filename>.
                        </para></listitem>
                    <listitem><para><filename>bb.decodeurl</filename>:
                        Use <filename>bb.fetch.decodeurl</filename>
                        </para></listitem>
                    <listitem><para><filename>bb.mkdirhier</filename>:
                        Use <filename>bb.utils.mkdirhier</filename>.
                        </para></listitem>
                    <listitem><para><filename>bb.movefile</filename>:
                        Use <filename>bb.utils.movefile</filename>.
                        </para></listitem>
                    <listitem><para><filename>bb.copyfile</filename>:
                        Use <filename>bb.utils.copyfile</filename>.
                        </para></listitem>
                    <listitem><para><filename>bb.which</filename>:
                        Use <filename>bb.utils.which</filename>.
                        </para></listitem>
                    <listitem><para><filename>bb.vercmp_string</filename>:
                        Use <filename>bb.utils.vercmp_string</filename>.
                        </para></listitem>
                    <listitem><para><filename>bb.vercmp</filename>:
                        Use <filename>bb.utils.vercmp</filename>.
                        </para></listitem>
                </itemizedlist>
            </para>
        </section>

        <section id='migration-1.6-bitbake-fetcher'>
            <title>SVK Fetcher</title>

            <para>
                The SVK fetcher has been removed from BitBake.
            </para>
        </section>

        <section id='migration-1.6-bitbake-console-output'>
            <title>Console Output Error Redirection</title>

            <para>
                The BitBake console UI will now output errors to
                <filename>stderr</filename> instead of
                <filename>stdout</filename>.
                Consequently, if you are piping or redirecting the output of
                <filename>bitbake</filename> to somewhere else, and you wish
                to retain the errors, you will need to add
                <filename>2>&amp;1</filename> (or something similar) to the
                end of your <filename>bitbake</filename> command line.
            </para>
        </section>

        <section id='migration-1.6-task-taskname-overrides'>
            <title><filename>task-&lt;taskname&gt;</filename> Overrides</title>

            <para>
                <filename>task-&lt;taskname&gt;</filename> overrides have been
                adjusted so that tasks whose names contain underscores have the
                underscores replaced by hyphens for the override so that they
                now function properly.
                For example, the task override for
                <filename>do_populate_sdk</filename> is
                <filename>task-populate-sdk</filename>.
            </para>
        </section>
    </section>

    <section id='migration-1.6-variable-changes'>
        <title>Changes to Variables</title>

        <para>
            The following variables have changed.
            For information on the OpenEmbedded build system variables, see the
            "<link linkend='ref-variables-glos'>Variables Glossary</link>" Chapter.
        </para>

        <section id='migration-1.6-variable-changes-TMPDIR'>
            <title><filename>TMPDIR</filename></title>

            <para>
                <link linkend='var-TMPDIR'><filename>TMPDIR</filename></link>
                can no longer be on an NFS mount.
                NFS does not offer full POSIX locking and inode consistency
                and can cause unexpected issues if used to store
                <filename>TMPDIR</filename>.
            </para>

            <para>
                The check for this occurs on startup.
                If <filename>TMPDIR</filename> is detected on an NFS mount,
                an error occurs.
            </para>
        </section>

        <section id='migration-1.6-variable-changes-PRINC'>
            <title><filename>PRINC</filename></title>

            <para>
                The
                <link linkend='var-PRINC'><filename>PRINC</filename></link>
                variable has been deprecated and triggers a warning if
                detected during a build.
                For
                <link linkend='var-PR'><filename>PR</filename></link>
                increments on changes, use the PR service instead.
                You can find out more about this service in the
                "<ulink url='&YOCTO_DOCS_DEV_URL;#working-with-a-pr-service'>Working With a PR Service</ulink>"
                section in the Yocto Project Development Manual.
            </para>
        </section>

        <section id='migration-1.6-variable-changes-IMAGE_TYPES'>
            <title><filename>IMAGE_TYPES</filename></title>

            <para>
                The "sum.jffs2" option for
                <link linkend='var-IMAGE_TYPES'><filename>IMAGE_TYPES</filename></link>
                has been replaced by the "jffs2.sum" option, which fits the
                processing order.
            </para>
        </section>

        <section id='migration-1.6-variable-changes-COPY_LIC_MANIFEST'>
            <title><filename>COPY_LIC_MANIFEST</filename></title>

            <para>
                The
                <link linkend='var-COPY_LIC_MANIFEST'><filename>COPY_LIC_MANIFEST</filename></link>
                variable must
                now be set to "1" rather than any value in order to enable
                it.
            </para>
        </section>

        <section id='migration-1.6-variable-changes-COPY_LIC_DIRS'>
            <title><filename>COPY_LIC_DIRS</filename></title>

            <para>
                The
                <link linkend='var-COPY_LIC_DIRS'><filename>COPY_LIC_DIRS</filename></link>
                variable must
                now be set to "1" rather than any value in order to enable
                it.
            </para>
        </section>

        <section id='migration-1.6-variable-changes-PACKAGE_GROUP'>
            <title><filename>PACKAGE_GROUP</filename></title>

            <para>
                The
                <link linkend='var-PACKAGE_GROUP'><filename>PACKAGE_GROUP</filename></link>
                variable has been renamed to
                <link linkend='var-FEATURE_PACKAGES'><filename>FEATURE_PACKAGES</filename></link>
                to more accurately reflect its purpose.
                You can still use <filename>PACKAGE_GROUP</filename> but
                the OpenEmbedded build system produces a warning message when
                it encounters the variable.
            </para>
        </section>
    </section>

    <section id='migration-1.6-directory-layout-changes'>
        <title>Directory Layout Changes</title>

        <para>
            The <filename>meta-hob</filename> layer has been removed from
            the top-level of the
            <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>.
            The contents of this layer are no longer needed by the Hob
            user interface for building images and toolchains.
        </para>
    </section>

    <section id='migration-1.6-build-changes'>
        <title>Build Changes</title>

        <para>
            Separate build and source directories have been enabled
            by default for selected recipes where it is known to work
            (a whitelist) and for all recipes that inherit the
            <link linkend='ref-classes-cmake'><filename>cmake</filename></link>
            class.
            In future releases the
            <link linkend='ref-classes-autotools'><filename>autotools</filename></link>
            class will enable a separate build directory by default as
            well.
            Recipes building Autotools-based
            software that fails to build with a separate build directory
            should be changed to inherit from the
            <link linkend='ref-classes-autotools-brokensep'><filename>autotools-brokensep</filename></link>
            class instead of the <filename>autotools</filename> class.
        </para>
    </section>

    <section id='migration-1.6-building-qemu-native'>
        <title><filename>qemu-native</filename></title>

        <para>
            <filename>qemu-native</filename> now builds without
            SDL-based graphical output support by default.
            The following additional lines are needed in your
            <filename>local.conf</filename> to enable it:
            <literallayout class='monospaced'>
     PACKAGECONFIG_pn-qemu-native = "sdl"
     ASSUME_PROVIDED += "libsdl-native"
            </literallayout>
            <note>
                The default <filename>local.conf</filename>
                contains these statements.
                Consequently, if you are building a headless system and using
                a default <filename>local.conf</filename> file, you will need
                comment these two lines out.
            </note>
        </para>
    </section>

    <section id='migration-1.6-core-image-basic'>
        <title><filename>core-image-basic</filename></title>

        <para>
            <filename>core-image-basic</filename> has been renamed to
            <filename>core-image-full-cmdline</filename>.
        </para>

        <para>
            In addition to <filename>core-image-basic</filename> being renamed,
            <filename>packagegroup-core-basic</filename> has been renamed to
            <filename>packagegroup-core-full-cmdline</filename> to match.
        </para>
    </section>

    <section id='migration-1.6-licensing'>
        <title>Licensing</title>

        <para>
            The top-level <filename>LICENSE</filename> file has been changed
            to better describe the license of the various components of
            OE-Core.
            However, the licensing itself remains unchanged.
        </para>

        <para>
            Normally, this change would not cause any side-effects.
            However, some recipes point to this file within
            <link linkend='var-LIC_FILES_CHKSUM'><filename>LIC_FILES_CHKSUM</filename></link>
            (as <filename>${COREBASE}/LICENSE</filename>) and thus the
            accompanying checksum must be changed from
            3f40d7994397109285ec7b81fdeb3b58 to
            4d92cd373abda3937c2bc47fbc49d690.
            A better alternative is to have
            <filename>LIC_FILES_CHKSUM</filename> point to a file
            describing the license that is distributed with the source
            that the recipe is building, if possible, rather than pointing
            to <filename>${COREBASE}/LICENSE</filename>.
        </para>
    </section>

    <section id='migration-1.6-cflags-options'>
        <title><filename>CFLAGS</filename> Options</title>

        <para>
            The "-fpermissive" option has been removed from the default
            <link linkend='var-CFLAGS'><filename>CFLAGS</filename></link>
            value.
            You need to take action on individual recipes that fail when
            building with this option.
            You need to either patch the recipes to fix the issues reported by
            the compiler, or you need to add "-fpermissive" to
            <filename>CFLAGS</filename> in the recipes.
        </para>
    </section>

    <section id='migration-1.6-custom-images'>
        <title>Custom Image Output Types</title>

        <para>
            Custom image output types, as selected using
            <link linkend='var-IMAGE_FSTYPES'><filename>IMAGE_FSTYPES</filename></link>,
            must declare their dependencies on other image types (if any) using
            a new
            <link linkend='var-IMAGE_TYPEDEP'><filename>IMAGE_TYPEDEP</filename></link>
            variable.
        </para>
    </section>

    <section id='migration-1.6-do-package-write-task'>
        <title>Tasks</title>

        <para>
            The <filename>do_package_write</filename> task has been removed.
            The task is no longer needed.
        </para>
    </section>

    <section id='migration-1.6-update-alternatives-provider'>
        <title><filename>update-alternative</filename> Provider</title>

        <para>
            The default <filename>update-alternatives</filename> provider has
            been changed from <filename>opkg</filename> to
            <filename>opkg-utils</filename>.
            This change resolves some troublesome circular dependencies.
            The runtime package has also been renamed from
            <filename>update-alternatives-cworth</filename>
            to <filename>update-alternatives-opkg</filename>.
        </para>
    </section>

    <section id='migration-1.6-virtclass-overrides'>
        <title><filename>virtclass</filename> Overrides</title>

        <para>
            The <filename>virtclass</filename> overrides are now deprecated.
            Use the equivalent class overrides instead (e.g.
            <filename>virtclass-native</filename> becomes
            <filename>class-native</filename>.)
        </para>
    </section>

    <section id='migration-1.6-removed-renamed-recipes'>
        <title>Removed and Renamed Recipes</title>

        <para>
            The following recipes have been removed:
            <itemizedlist>
                <listitem><para><filename>packagegroup-toolset-native</filename> -
                    This recipe is largely unused.
                    </para></listitem>
                <listitem><para><filename>linux-yocto-3.8</filename> -
                    Support for the Linux yocto 3.8 kernel has been dropped.
                    Support for the 3.10 and 3.14 kernels have been added
                    with the <filename>linux-yocto-3.10</filename> and
                    <filename>linux-yocto-3.14</filename> recipes.
                    </para></listitem>
                <listitem><para><filename>ocf-linux</filename> -
                    This recipe has been functionally replaced using
                    <filename>cryptodev-linux</filename>.
                    </para></listitem>
                <listitem><para><filename>genext2fs</filename> -
                    <filename>genext2fs</filename> is no longer used by the
                    build system and is unmaintained upstream.
                    </para></listitem>
                <listitem><para><filename>js</filename> -
                    This provided an ancient version of Mozilla's javascript
                    engine that is no longer needed.
                    </para></listitem>
                <listitem><para><filename>zaurusd</filename> -
                    The recipe has been moved to the
                    <filename>meta-handheld</filename> layer.
                    </para></listitem>
                <listitem><para><filename>eglibc 2.17</filename> -
                    Replaced by the <filename>eglibc 2.19</filename>
                    recipe.
                    </para></listitem>
                <listitem><para><filename>gcc 4.7.2</filename> -
                    Replaced by the now stable
                    <filename>gcc 4.8.2</filename>.
                    </para></listitem>
                <listitem><para><filename>external-sourcery-toolchain</filename> -
                    this recipe is now maintained in the
                    <filename>meta-sourcery</filename> layer.
                    </para></listitem>
                <listitem><para><filename>linux-libc-headers-yocto 3.4+git</filename> -
                    Now using version 3.10 of the
                    <filename>linux-libc-headers</filename> by default.
                    </para></listitem>
                <listitem><para><filename>meta-toolchain-gmae</filename> -
                    This recipe is obsolete.
                    </para></listitem>
                <listitem><para><filename>packagegroup-core-sdk-gmae</filename> -
                    This recipe is obsolete.
                    </para></listitem>
                <listitem><para><filename>packagegroup-core-standalone-gmae-sdk-target</filename> -
                    This recipe is obsolete.
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.6-removed-classes'>
        <title>Removed Classes</title>

        <para>
            The following classes have become obsolete and have been removed:
            <itemizedlist>
                <listitem><para><filename>module_strip</filename>
                    </para></listitem>
                <listitem><para><filename>pkg_metainfo</filename>
                    </para></listitem>
                <listitem><para><filename>pkg_distribute</filename>
                    </para></listitem>
                <listitem><para><filename>image-empty</filename>
                    </para></listitem>
            </itemizedlist>
        </para>
    </section>

    <section id='migration-1.6-reference-bsps'>
        <title>Reference Board Support Packages (BSPs)</title>

        <para>
            The following reference BSPs changes occurred:
            <itemizedlist>
                <listitem><para>The BeagleBoard
                    (<filename>beagleboard</filename>) ARM reference hardware
                    has been replaced by the BeagleBone
                    (<filename>beaglebone</filename>) hardware.
                    </para></listitem>
                <listitem><para>The RouterStation Pro
                    (<filename>routerstationpro</filename>) MIPS reference
                    hardware has been replaced by the EdgeRouter Lite
                    (<filename>edgerouter</filename>) hardware.
                    </para></listitem>
            </itemizedlist>
            The previous reference BSPs for the
            <filename>beagleboard</filename> and
            <filename>routerstationpro</filename> machines are still available
            in a new <filename>meta-yocto-bsp-old</filename> layer in the
            <ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink>
            at
            <ulink url='http://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto-bsp-old/'>http://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto-bsp-old/</ulink>.
        </para>
    </section>
</section>
</chapter>
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