sdk-manual: describe how to use extensible SDK functionality directly in a Yocto build

(From yocto-docs rev: 7e1b2e4238c2260fd74295dd208ec774e0e6bf68)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Reviewed-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/sdk-manual/appendix-customizing.rst

@@ -1,11 +1,17 @@
 .. SPDX-License-Identifier: CC-BY-SA-2.0-UK
 
-******************************
-Customizing the Extensible SDK
-******************************
+***************************************************
+Customizing the Extensible SDK standalone installer
+***************************************************
 
 This appendix describes customizations you can apply to the extensible
-SDK.
+SDK when using in the standalone installer version.
+
+.. note::
+
+   It is also possible to use the Extensible SDK functionality directly in a
+   Yocto build, avoiding separate installer artefacts. Please refer to
+   ":ref:`sdk-manual/extensible:Installing the Extensible SDK`"
 
 Configuring the Extensible SDK
 ==============================

documentation/sdk-manual/appendix-obtain.rst

@@ -4,8 +4,22 @@
 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
@@ -72,7 +86,7 @@ Follow these steps to locate and hand-install the toolchain:
    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:

documentation/sdk-manual/extensible.rst

@@ -41,6 +41,42 @@ functionality.
 Installing the Extensible SDK
 =============================
 
+Two ways to install the Extensible SDK
+--------------------------------------
+
+Extensible SDK can be installed in two different ways, and both have
+their own pros and cons:
+
+1. *Setting up the Extensible SDK environment directly in a Yocto build*. This
+avoids having to produce, test, distribute and maintain separate SDK installer
+archives, which can get very large. There is only one environment for the regular
+Yocto build and the SDK and less code paths where things can go not according to plan.
+It's easier to update the SDK: it simply means updating the Yocto layers with
+git fetch or layer management tooling. The SDK extensibility is better than in the
+second option: just run ``bitbake`` again to add more things to the sysroot, or add layers
+if even more things are required.
+
+2. *Setting up the Extensible SDK from a standalone installer*. This has the benefit of
+having a single, self-contained archive that includes all the needed binary artifacts.
+So nothing needs to be rebuilt, and there is no need to provide a well-functioning
+binary artefact cache over the network for developers with underpowered laptops.
+
+Setting up the Extensible SDK environment directly in a Yocto build
+-------------------------------------------------------------------
+
+1. Set up all the needed layers and a Yocto build directory, e.g. a regular Yocto
+   build where ``bitbake`` can be executed.
+
+2. Run:
+    $ bitbake meta-ide-support
+    $ bitbake -c populate_sysroot gtk+3
+    (or any other target or native item that the application developer would need)
+    $ bitbake populate-sysroots
+
+
+Setting up the Extensible SDK from a standalone installer
+---------------------------------------------------------
+
 The first thing you need to do is install the SDK on your :term:`Build
 Host` by running the ``*.sh`` installation script.
 
@@ -136,7 +172,12 @@ Running the Extensible SDK Environment Setup Script
 ===================================================
 
 Once you have the SDK installed, you must run the SDK environment setup
-script before you can actually use the SDK. This setup script resides in
+script before you can actually use the SDK.
+
+When using a SDK directly in a Yocto build, you will find the script in
+``tmp/deploy/images/qemux86-64/`` in your build directory.
+
+When using a standalone SDK installer, this setup script resides in
 the directory you chose when you installed the SDK, which is either the
 default ``poky_sdk`` directory or the directory you chose during
 installation.
@@ -154,6 +195,11 @@ script is for an IA-based target machine using i586 tuning::
    SDK environment now set up; additionally you may now run devtool to perform development tasks.
    Run devtool --help for further details.
 
+When using the environment script directly in a Yocto build, it can
+be run similarly:
+
+   $ source tmp/deploy/images/qemux86-64/environment-setup-core2-64-poky-linux
+
 Running the setup script defines many environment variables needed in
 order to use the SDK (e.g. ``PATH``,
 :term:`CC`,
@@ -1215,9 +1261,23 @@ need to link to libGL but you are not sure which recipe provides libGL.
 You can use the following command to find out::
 
    $ devtool search libGL mesa
+   A free implementation of the OpenGL API
 
-A free implementation of the OpenGL API Once you know the recipe
-(i.e. ``mesa`` in this example), you can install it::
+Once you know the recipe
+(i.e. ``mesa`` in this example), you can install it.
+
+When using the extensible SDK directly in a Yocto build
+-------------------------------------------------------
+
+In this scenario, the Yocto build tooling, e.g. ``bitbake``
+is directly accessible to build additional items, and it
+can simply be executed directly:
+
+   $ bitbake mesa
+   $ bitbake populate-sysroots
+
+When using a standalone installer for the Extensible SDK
+--------------------------------------------------------
 
    $ devtool sdk-install mesa
 

documentation/sdk-manual/working-projects.rst

@@ -88,9 +88,13 @@ project:
 
       $ source /opt/poky/&DISTRO;/environment-setup-i586-poky-linux
 
+   Another example is sourcing the environment setup directly in a Yocto
+   build::
+
+      $ source tmp/deploy/images/qemux86-64/environment-setup-core2-64-poky-linux
+
 3. *Create the configure Script:* Use the ``autoreconf`` command to
-   generate the ``configure`` script.
-   ::
+   generate the ``configure`` script::
 
       $ autoreconf
 
@@ -279,6 +283,11 @@ example:
 
       $ source /opt/poky/&DISTRO;/environment-setup-i586-poky-linux
 
+   Another example is sourcing the environment setup directly in a Yocto
+   build::
+
+      $ source tmp/deploy/images/qemux86-64/environment-setup-core2-64-poky-linux
+
 3. *Create the Makefile:* For this example, the Makefile contains
    two lines that can be used to set the :term:`CC` variable. One line is
    identical to the value that is set when you run the SDK environment