doc: Move the source tree description out of app development

It is quite confusing to describe Zephyr's source tree layout in the
section for application development, given that applications do not need
to follow the exact same layout as the main tree.
Instead move this section to the contribution guidelines chapter.

Signed-off-by: Carles Cufi <[email protected]>

Author: carlescufi

doc/contribute/guidelines.rst

@@ -200,17 +200,106 @@ on https://github.com and have Git tools available on your development system.
    details link near the end of the PR conversation list. See
    `Continuous Integration`_ for more information
 
-Repository layout
-*****************
+.. _source_tree_v2:
+
+Source Tree Structure
+*********************
 
-To clone the main Zephyr Project repositories use the instructions in
+To clone the main Zephyr Project repository use the instructions in
 :ref:`get_the_code`.
 
-The Zephyr project directory structure is described in :ref:`source_tree_v2`
-documentation. In addition to the Zephyr kernel itself, you'll also find the
-sources for technical documentation, sample code, supported board
-configurations, and a collection of subsystem tests.  All of these are
-available for developers to contribute to and enhance.
+This section describes the main repository's source tree. In addition to the
+Zephyr kernel itself, you'll also find the sources for technical documentation,
+sample code, supported board configurations, and a collection of subsystem
+tests.  All of these are available for developers to contribute to and enhance.
+
+Understanding the Zephyr source tree can help locate the code
+associated with a particular Zephyr feature.
+
+At the top of the tree, several files are of importance:
+
+:file:`CMakeLists.txt`
+    The top-level file for the CMake build system, containing a lot of the
+    logic required to build Zephyr.
+
+:file:`Kconfig`
+    The top-level Kconfig file, which refers to the file :file:`Kconfig.zephyr`
+    also found in the top-level directory.
+
+    See :ref:`the Kconfig section of the manual <kconfig>` for detailed Kconfig
+    documentation.
+
+:file:`west.yml`
+    The :ref:`west` manifest, listing the external repositories managed by
+    the west command-line tool.
+
+The Zephyr source tree also contains the following top-level
+directories, each of which may have one or more additional levels of
+subdirectories not described here.
+
+:file:`arch`
+    Architecture-specific kernel and system-on-chip (SoC) code.
+    Each supported architecture (for example, x86 and ARM)
+    has its own subdirectory,
+    which contains additional subdirectories for the following areas:
+
+    * architecture-specific kernel source files
+    * architecture-specific kernel include files for private APIs
+
+:file:`soc`
+    SoC related code and configuration files.
+
+:file:`boards`
+    Board related code and configuration files.
+
+:file:`doc`
+    Zephyr technical documentation source files and tools used to
+    generate the https://docs.zephyrproject.org web content.
+
+:file:`drivers`
+    Device driver code.
+
+:file:`dts`
+    :ref:`devicetree <dt-guide>` source files used to describe non-discoverable
+    board-specific hardware details.
+
+:file:`include`
+    Include files for all public APIs, except those defined under :file:`lib`.
+
+:file:`kernel`
+    Architecture-independent kernel code.
+
+:file:`lib`
+    Library code, including the minimal standard C library.
+
+:file:`misc`
+    Miscellaneous code that doesn't belong to any of the other top-level
+    directories.
+
+:file:`samples`
+    Sample applications that demonstrate the use of Zephyr features.
+
+:file:`scripts`
+    Various programs and other files used to build and test Zephyr
+    applications.
+
+:file:`cmake`
+    Additional build scripts needed to build Zephyr.
+
+:file:`subsys`
+    Subsystems of Zephyr, including:
+
+    * USB device stack code
+    * Networking code, including the Bluetooth stack and networking stacks
+    * File system code
+    * Bluetooth host and controller
+
+:file:`tests`
+    Test code and benchmarks for Zephyr features.
+
+:file:`share`
+    Additional architecture independent data. It currently contains Zephyr's CMake
+    package.
 
 Pull Requests and Issues
 ************************

doc/develop/application/index.rst

@@ -67,101 +67,6 @@ generated in a build directory; Zephyr does not support "in-tree" builds.
 The following sections describe how to create, build, and run Zephyr
 applications, followed by more detailed reference material.
 
-
-.. _source_tree_v2:
-
-Source Tree Structure
-*********************
-
-Understanding the Zephyr source tree can be helpful in locating the code
-associated with a particular Zephyr feature.
-
-At the top of the tree there are several files that are of importance:
-
-:file:`CMakeLists.txt`
-    The top-level file for the CMake build system, containing a lot of the
-    logic required to build Zephyr.
-
-:file:`Kconfig`
-    The top-level Kconfig file, which refers to the file :file:`Kconfig.zephyr`
-    also found at the top-level directory.
-
-    See :ref:`the Kconfig section of the manual <kconfig>` for detailed Kconfig
-    documentation.
-
-:file:`west.yml`
-    The :ref:`west` manifest, listing the external repositories managed by
-    the west command-line tool.
-
-The Zephyr source tree also contains the following top-level
-directories, each of which may have one or more additional levels of
-subdirectories which are not described here.
-
-:file:`arch`
-    Architecture-specific kernel and system-on-chip (SoC) code.
-    Each supported architecture (for example, x86 and ARM)
-    has its own subdirectory,
-    which contains additional subdirectories for the following areas:
-
-    * architecture-specific kernel source files
-    * architecture-specific kernel include files for private APIs
-
-:file:`soc`
-    SoC related code and configuration files.
-
-:file:`boards`
-    Board related code and configuration files.
-
-:file:`doc`
-    Zephyr technical documentation source files and tools used to
-    generate the https://docs.zephyrproject.org web content.
-
-:file:`drivers`
-    Device driver code.
-
-:file:`dts`
-    :ref:`devicetree <dt-guide>` source files used to describe non-discoverable
-    board-specific hardware details.
-
-:file:`include`
-    Include files for all public APIs, except those defined under :file:`lib`.
-
-:file:`kernel`
-    Architecture-independent kernel code.
-
-:file:`lib`
-    Library code, including the minimal standard C library.
-
-:file:`misc`
-    Miscellaneous code that doesn't belong to any of the other top-level
-    directories.
-
-:file:`samples`
-    Sample applications that demonstrate the use of Zephyr features.
-
-:file:`scripts`
-    Various programs and other files used to build and test Zephyr
-    applications.
-
-:file:`cmake`
-    Additional build scripts needed to build Zephyr.
-
-:file:`subsys`
-    Subsystems of Zephyr, including:
-
-    * USB device stack code.
-    * Networking code, including the Bluetooth stack and networking stacks.
-    * File system code.
-    * Bluetooth host and controller
-
-:file:`tests`
-    Test code and benchmarks for Zephyr features.
-
-:file:`share`
-    Additional architecture independent data. Currently containing Zephyr CMake
-    package.
-
-
 Example standalone application
 ******************************