| .. SPDX-License-Identifier: CC-BY-SA-2.0-UK |
| |
| ***************** |
| Obtaining the SDK |
| ***************** |
| |
| Working with the SDK components directly in a Yocto build |
| ========================================================= |
| |
| Please refer to section |
| ":ref:`sdk-manual/extensible:Setting up the Extensible SDK environment directly in a Yocto build`" |
| |
| Note that to use this feature effectively either a powerful build |
| machine, or a well-functioning sstate cache infrastructure is required: |
| otherwise significant time could be spent waiting for components to be built |
| by BitBake from source code. |
| |
| Working with standalone SDK Installers |
| ====================================== |
| |
| Locating Pre-Built SDK Installers |
| --------------------------------- |
| |
| You can use existing, pre-built toolchains by locating and running an |
| SDK installer script that ships with the Yocto Project. Using this |
| method, you select and download an architecture-specific SDK installer |
| and then run the script to hand-install the toolchain. |
| |
| Follow these steps to locate and hand-install the toolchain: |
| |
| #. *Go to the Installers Directory:* Go to |
| :yocto_dl:`/releases/yocto/yocto-&DISTRO;/toolchain/` |
| |
| #. *Open the Folder for Your Build Host:* Open the folder that matches |
| your :term:`Build Host` (i.e. |
| ``i686`` for 32-bit machines or ``x86_64`` for 64-bit machines). |
| |
| #. *Locate and Download the SDK Installer:* You need to find and |
| download the installer appropriate for your build host, target |
| hardware, and image type. |
| |
| The installer files (``*.sh``) follow this naming convention: |
| ``poky-glibc-host_system-core-image-type-arch-toolchain[-ext]-release.sh``: |
| |
| - ``host_system``: string representing your development system: ``i686`` or ``x86_64`` |
| |
| - ``type``: string representing the image: ``sato`` or ``minimal`` |
| |
| - ``arch``: string representing the target architecture such as ``cortexa57-qemuarm64`` |
| |
| - ``release``: version of the Yocto Project. |
| |
| .. note:: |
| The standard SDK installer does not have the ``-ext`` string as |
| part of the filename. |
| |
| The toolchains provided by the Yocto |
| Project are based off of the ``core-image-sato`` and |
| ``core-image-minimal`` images and contain libraries appropriate for |
| developing against those images. |
| |
| For example, if your build host is a 64-bit x86 system and you need |
| an extended SDK for a 64-bit core2 QEMU target, go into the ``x86_64`` |
| folder and download the following installer:: |
| |
| poky-glibc-x86_64-core-image-sato-core2-64-qemux86-64-toolchain-&DISTRO;.sh |
| |
| #. *Run the Installer:* Be sure you have execution privileges and run |
| the installer. Following is an example from the ``Downloads`` |
| directory:: |
| |
| $ ~/Downloads/poky-glibc-x86_64-core-image-sato-core2-64-qemux86-64-toolchain-&DISTRO;.sh |
| |
| During execution of the script, you choose the root location for the |
| toolchain. See the |
| ":ref:`sdk-manual/appendix-obtain:installed standard sdk directory structure`" |
| section and the |
| ":ref:`sdk-manual/appendix-obtain:installed extensible sdk directory structure`" |
| section for more information. |
| |
| Building an SDK Installer |
| ------------------------- |
| |
| As an alternative to locating and downloading an SDK installer, you can |
| build the SDK installer. Follow these steps: |
| |
| #. *Set Up the Build Environment:* Be sure you are set up to use BitBake |
| in a shell. See the ":ref:`dev-manual/start:preparing the build host`" section |
| in the Yocto Project Development Tasks Manual for information on how |
| to get a build host ready that is either a native Linux machine or a |
| machine that uses CROPS. |
| |
| #. *Clone the ``poky`` Repository:* You need to have a local copy of the |
| Yocto Project :term:`Source Directory` |
| (i.e. a local |
| ``poky`` repository). See the ":ref:`dev-manual/start:cloning the \`\`poky\`\` repository`" and |
| possibly the ":ref:`dev-manual/start:checking out by branch in poky`" and |
| ":ref:`dev-manual/start:checking out by tag in poky`" sections |
| all in the Yocto Project Development Tasks Manual for information on |
| how to clone the ``poky`` repository and check out the appropriate |
| branch for your work. |
| |
| #. *Initialize the Build Environment:* While in the root directory of |
| the Source Directory (i.e. ``poky``), run the |
| :ref:`structure-core-script` environment |
| setup script to define the OpenEmbedded build environment on your |
| build host:: |
| |
| $ source oe-init-build-env |
| |
| Among other things, the script creates the :term:`Build Directory`, which |
| is ``build`` in this case and is located in the Source Directory. After |
| the script runs, your current working directory is set to the ``build`` |
| directory. |
| |
| #. *Make Sure You Are Building an Installer for the Correct Machine:* |
| Check to be sure that your :term:`MACHINE` variable in the ``local.conf`` |
| file in your :term:`Build Directory` matches the architecture |
| for which you are building. |
| |
| #. *Make Sure Your SDK Machine is Correctly Set:* If you are building a |
| toolchain designed to run on an architecture that differs from your |
| current development host machine (i.e. the build host), be sure that |
| the :term:`SDKMACHINE` variable in the ``local.conf`` file in your |
| :term:`Build Directory` is correctly set. |
| |
| .. note:: |
| |
| If you are building an SDK installer for the Extensible SDK, the |
| :term:`SDKMACHINE` value must be set for the architecture of the |
| machine you are using to build the installer. If :term:`SDKMACHINE` |
| is not set appropriately, the build fails and provides an error |
| message similar to the following:: |
| |
| The extensible SDK can currently only be built for the same |
| architecture as the machine being built on - SDK_ARCH |
| is set to i686 (likely via setting SDKMACHINE) which is |
| different from the architecture of the build machine (x86_64). |
| Unable to continue. |
| |
| |
| #. *Build the SDK Installer:* To build the SDK installer for a standard |
| SDK and populate the SDK image, use the following command form. Be |
| sure to replace ``image`` with an image (e.g. "core-image-sato"):: |
| |
| $ bitbake image -c populate_sdk |
| |
| You can do the same for the extensible SDK using this command form:: |
| |
| $ bitbake image -c populate_sdk_ext |
| |
| These commands produce an SDK installer that contains the sysroot |
| that matches your target root filesystem. |
| |
| When the ``bitbake`` command completes, the SDK installer will be in |
| ``tmp/deploy/sdk`` in the :term:`Build Directory`. |
| |
| .. note:: |
| |
| - By default, the previous BitBake command does not build static |
| binaries. If you want to use the toolchain to build these types |
| of libraries, you need to be sure your SDK has the appropriate |
| static development libraries. Use the |
| :term:`TOOLCHAIN_TARGET_TASK` |
| variable inside your ``local.conf`` file before building the |
| SDK installer. Doing so ensures that the eventual SDK |
| installation process installs the appropriate library packages |
| as part of the SDK. Following is an example using ``libc`` |
| static development libraries: TOOLCHAIN_TARGET_TASK:append = " |
| libc-staticdev" |
| |
| #. *Run the Installer:* You can now run the SDK installer from |
| ``tmp/deploy/sdk`` in the :term:`Build Directory`. Following is an example:: |
| |
| $ cd poky/build/tmp/deploy/sdk |
| $ ./poky-glibc-x86_64-core-image-sato-core2-64-toolchain-ext-&DISTRO;.sh |
| |
| During execution of the script, you choose the root location for the |
| toolchain. See the |
| ":ref:`sdk-manual/appendix-obtain:installed standard sdk directory structure`" |
| section and the |
| ":ref:`sdk-manual/appendix-obtain:installed extensible sdk directory structure`" |
| section for more information. |
| |
| Extracting the Root Filesystem |
| ============================== |
| |
| After installing the toolchain, for some use cases you might need to |
| separately extract a root filesystem: |
| |
| - You want to boot the image using NFS. |
| |
| - You want to use the root filesystem as the target sysroot. |
| |
| - You want to develop your target application using the root filesystem |
| as the target sysroot. |
| |
| Follow these steps to extract the root filesystem: |
| |
| #. *Locate and Download the Tarball for the Pre-Built Root Filesystem |
| Image File:* You need to find and download the root filesystem image |
| file that is appropriate for your target system. These files are kept |
| in machine-specific folders in the |
| :yocto_dl:`Index of Releases </releases/yocto/yocto-&DISTRO;/machines/>` |
| in the "machines" directory. |
| |
| The machine-specific folders of the "machines" directory contain |
| tarballs (``*.tar.bz2``) for supported machines. These directories |
| also contain flattened root filesystem image files (``*.ext4``), |
| which you can use with QEMU directly. |
| |
| The pre-built root filesystem image files follow the |
| ``core-image-profile-machine.tar.bz2`` naming convention: |
| |
| - ``profile``: filesystem image's profile, such as ``minimal``, |
| ``minimal-dev`` or ``sato``. For information on these types of image |
| profiles, see the "Images" chapter in the Yocto Project Reference Manual. |
| |
| - ``machine``: same string as the name of the parent download directory. |
| |
| The root filesystems |
| provided by the Yocto Project are based off of the |
| ``core-image-sato`` and ``core-image-minimal`` images. |
| |
| For example, if you plan on using a BeagleBone device as your target |
| hardware and your image is a ``core-image-sato-sdk`` image, you can |
| download the following file:: |
| |
| core-image-sato-sdk-beaglebone-yocto.tar.bz2 |
| |
| #. *Initialize the Cross-Development Environment:* You must ``source`` |
| the cross-development environment setup script to establish necessary |
| environment variables. |
| |
| This script is located in the top-level directory in which you |
| installed the toolchain (e.g. ``poky_sdk``). |
| |
| Following is an example based on the toolchain installed in the |
| ":ref:`sdk-manual/appendix-obtain:locating pre-built sdk installers`" section:: |
| |
| $ source poky_sdk/environment-setup-core2-64-poky-linux |
| |
| #. *Extract the Root Filesystem:* Use the ``runqemu-extract-sdk`` |
| command and provide the root filesystem image. |
| |
| Following is an example command that extracts the root filesystem |
| from a previously built root filesystem image that was downloaded |
| from the :yocto_dl:`Index of Releases </releases/yocto/yocto-&DISTRO;/machines/>`. |
| This command extracts the root filesystem into the ``core2-64-sato`` |
| directory:: |
| |
| $ runqemu-extract-sdk ~/Downloads/core-image-sato-sdk-beaglebone-yocto.tar.bz2 ~/beaglebone-sato |
| |
| You could now point to the target sysroot at ``beaglebone-sato``. |
| |
| Installed Standard SDK Directory Structure |
| ========================================== |
| |
| The following figure shows the resulting directory structure after you |
| install the Standard SDK by running the ``*.sh`` SDK installation |
| script: |
| |
| .. image:: figures/sdk-installed-standard-sdk-directory.png |
| :scale: 100% |
| |
| The installed SDK consists of an environment setup script for the SDK, a |
| configuration file for the target, a version file for the target, and |
| the root filesystem (``sysroots``) needed to develop objects for the |
| target system. |
| |
| Within the figure, italicized text is used to indicate replaceable |
| portions of the file or directory name. For example, install_dir/version |
| is the directory where the SDK is installed. By default, this directory |
| is ``/opt/poky/``. And, version represents the specific snapshot of the |
| SDK (e.g. &DISTRO;). Furthermore, target represents the target architecture |
| (e.g. ``i586``) and host represents the development system's |
| architecture (e.g. ``x86_64``). Thus, the complete names of the two |
| directories within the ``sysroots`` could be ``i586-poky-linux`` and |
| ``x86_64-pokysdk-linux`` for the target and host, respectively. |
| |
| Installed Extensible SDK Directory Structure |
| ============================================ |
| |
| The following figure shows the resulting directory structure after you |
| install the Extensible SDK by running the ``*.sh`` SDK installation |
| script: |
| |
| .. image:: figures/sdk-installed-extensible-sdk-directory.png |
| :scale: 80% |
| :align: center |
| |
| The installed directory structure for the extensible SDK is quite |
| different than the installed structure for the standard SDK. The |
| extensible SDK does not separate host and target parts in the same |
| manner as does the standard SDK. The extensible SDK uses an embedded |
| copy of the OpenEmbedded build system, which has its own sysroots. |
| |
| Of note in the directory structure are an environment setup script for |
| the SDK, a configuration file for the target, a version file for the |
| target, and log files for the OpenEmbedded build system preparation |
| script run by the installer and BitBake. |
| |
| Within the figure, italicized text is used to indicate replaceable |
| portions of the file or directory name. For example, install_dir is the |
| directory where the SDK is installed, which is ``poky_sdk`` by default, |
| and target represents the target architecture (e.g. ``i586``). |