Docs: Restructuring and new layout

This patch implements a set of user-experiences aimed
changes.It modifies the documentation structure and
switches to a more reactive design for the rtd theme.

* The documentation layout has been redesigned to be more
  intuitive,easier to maintain and and scale.
* The landing page introduces a new dashboard.
* Introduced dedicated space for release documents, and
  changelog has been modified to directly source content
  from referenced documents.
* Added quick-link navigation for items that need emphasis.
* Relevant design documents can now be grouped in suf-folders.
* There is dedicated space for custom platform, and third
  party tools documents.
* Wildcard and regex matching has been introduced to indexes.

Change-Id: Ib02d17d5d26187d397ba17317788cf2a01401b07
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/docs/getting_started/tfm_sw_requirement.rst b/docs/getting_started/tfm_sw_requirement.rst
new file mode 100644
index 0000000..2c3d555
--- /dev/null
+++ b/docs/getting_started/tfm_sw_requirement.rst
@@ -0,0 +1,566 @@
+#####################
+Software requirements
+#####################
+
+.. |DS5_VERSION| replace:: v5.29.1
+.. |KEIL_VERSION| replace:: v5.25.2
+.. |DEV_STUDIO_VERSION| replace:: 2018.0
+
+A quick reference table is included in the
+:ref:`docs/getting_started/tfm_sw_requirement:Tool & Dependency overview` section
+of this document.
+
+****************************
+Supported build environments
+****************************
+
+TF-M officially supports a limited set of build environments and setups. In
+this context, official support means that the environments listed below
+are actively used by team members and active developers hence users should
+be able to recreate the same configurations by following the instructions
+described below. In case of problems, the TF-M team provides support
+only for these environments, but building in other environments can still be
+possible.
+
+The following environments are supported:
+
+    - Ubuntu 16.04 x64
+    - Ubuntu 18.04 x64
+    - Windows 10 x64 + git-bash (MinGW) + gnumake from DS-5 or msys2.
+    - Windows 10 x64 + Cygwin x64 (example configuration is provided for
+      this Windows setup only).
+
+.. note::
+    Some tools (i.e. python3 and CMake) must NOT be installed from
+    Cygwin and instead a native windows version is needed. Please see the
+    chapter `Windows + Cygwin setup`_ below.
+
+*********************
+Supported C compilers
+*********************
+
+To compile TF-M code, at least one of the supported compiler toolchains have to
+be available in the build environment. The currently supported compiler
+versions are:
+
+    - Arm Compiler v6.10
+    - Arm Compiler v6.11
+    - Arm Compiler v6.12
+    - Arm Compiler v6.13
+    - GNU Arm compiler v6.3.1
+    - GNU Arm compiler v7.3
+
+.. Note::
+    - The Arm compilers above are provided via Keil uVision |KEIL_VERSION|
+      or greater, DS-5 |DS5_VERSION| or greater, and Development Studio
+      |DEV_STUDIO_VERSION| or greater, or they can be downloaded as standalone
+      packages from
+      `here <https://developer.arm.com/products/software-development-tools/compilers/arm-compiler/downloads/version-6>`__.
+
+    - Arm compiler specific environment variable may need updating based
+      on specific products and licenses as explained in
+      `product-and-toolkit-configuration <https://developer.arm.com/products/software-development-tools/license-management/resources/product-and-toolkit-configuration>`__.
+
+    - The GNU Arm compiler can be downloaded from
+      `here <https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads>`__.
+      On the page select *GNU Arm Embedded Toolchain: 6-2017-q1-update*
+      or *GNU Arm Embedded Toolchain: 7-2018-q2-update*
+
+************************
+Supported CMake versions
+************************
+
+The build-system is CMake based and supports the following versions:
+
+    - 3.7
+    - 3.10
+    - 3.11
+    - 3.12
+    - 3.13
+    - 3.14
+
+.. Note::
+    - Please use the latest build version available (i.e. 3.7.2 instead of
+      3.7.0).
+      While it is preferable to use the newest version this is not required
+      and any version from the above list should work.
+    - Recent versions of CMake can be downloaded from
+      https://cmake.org/download/, and older releases are available from
+      https://cmake.org/files.
+    - For Cygwin users, please use a native windows CMake version
+      instead of the version installed with Cygwin.
+
+***************************
+Supported GNU make versions
+***************************
+
+The TF-M team builds using the "Unix Makefiles" generator of CMake and
+thus GNU make is needed for the build. On Linux please use the version
+available from the official repository of your distribution.
+
+On Windows the following binaries are supported:
+
+    - GNU make v4.2.1 executable from Cygwin
+    - GNU make v4.2.1 executable from msys2
+    - GNU make v4.2 executable from DS5 |DS5_VERSION| (see <DS5 directory>/bin)
+
+CMake is quiet tolerant to GNU make versions and basically any
+"reasonably recent" GNU make version shall work.
+
+CMake generators other than "Unix Makefiles" may work, but are not
+officially supported.
+
+*********************
+External dependencies
+*********************
+
+In order to build TF-M the following external projects are required:
+
+    - `Mbed Crypto library <https://github.com/ARMmbed/mbed-crypto>`__ v3.0.1
+      is used as crypto library on the secure side
+    - `CMSIS Version 5 <https://github.com/ARM-software/CMSIS_5>`__ v5.5.0
+      is used to import RTX for the example non-secure app
+
+Each of the listed dependencies should be placed in a common root directory
+with trustedfirmware-m
+
+.. code-block:: bash
+
+    .
+    ├── CMSIS_5
+    ├── mbed-crypto
+    └── trusted-firmware-m
+
+.. Note::
+   `CMSIS_5` v5.5.0 has a known issue, affecting compilation using
+   Arm Compiler v6.10. Please refer to
+   `CMSIS release notes <https://github.com/ARM-software/CMSIS_5/releases>`__.
+   for guidance.
+
+********************************************
+Tools for configuring and programming boards
+********************************************
+
+For stm32l5xx boards, `STM32_Programmer_CLI  <https://www.st.com/en/development-tools/stm32cubeprog.html>`__ 
+is used to configure security protections and to write the code in internal flash.
+A version is available for Linux and Windows host machine.
+
+**************
+Example setups
+**************
+
+This section lists dependencies and some exact and tested steps to set-up a
+TF-M-m build environment under various OSes.
+
+Ubuntu setup
+============
+
+Install the following tools:
+
+- DS-5 |DS5_VERSION|.
+- Git tools v2.10.0
+- Git Large File Storage (git-lfs)
+- CMake (see the "Supported CMake versions" chapter)
+- GNU Make (see the "Supported make versions" chapter)
+- Python3 and the pip package manager (from Python 3.4 it's included)
+- Python3 packages: *cryptography, pyasn1, yaml, jinja2 v2.10, cbor v1.0.0*
+
+  .. code-block:: bash
+
+    pip3 install --user cryptography pyasn1 pyyaml jinja2 cbor
+
+- SRecord v1.58 (for Musca test chip boards)
+
+Setup a shell to enable compiler toolchain and CMake after installation.
+------------------------------------------------------------------------
+
+To import Arm Compiler v6.10 in your bash shell console:
+
+.. Warning::
+    Arm compiler specific environment variable may need updating based on
+    specific products and licenses as explained in
+    `product-and-toolkit-configuration <https://developer.arm.com/products/software-development-tools/license-management/resources/product-and-toolkit-configuration>`__.
+
+.. code-block:: bash
+
+    export PATH=<DS-5_PATH>/sw/ARMCompiler6.10/bin:$PATH
+    export ARM_TOOL_VARIANT=ult
+    export ARM_PRODUCT_PATH=<DS-5_PATH>/sw/mappings
+    export ARMLMD_LICENSE_FILE=<LICENSE_FILE_PATH>
+
+To import CMake in your bash shell console:
+
+.. code-block:: bash
+
+    export PATH=/bin:$PATH
+
+To import GNU Arm in your bash shell console:
+
+.. code-block:: bash
+
+    export PATH=/bin:$PATH
+
+Windows + Cygwin setup
+======================
+
+Install the following tools:
+
+- uVision |KEIL_VERSION| or DS-5 |DS5_VERSION| (DS-5 Ultimate Edition) which
+  provides the Arm Compiler v6.10 compiler or GNU Arm compiler v6.3.1.
+- Git client latest version (https://git-scm.com/download/win)
+- Git Large File Storage (`native Windows version <https://git-lfs.github.com/>`__,
+- CMake (`native Windows version <https://cmake.org/download/>`__,
+  see the `Supported CMake versions`_ chapter)
+- `Cygwin <https://www.cygwin.com/>`__. Tests done with version 2.877
+  (64 bits)
+- GNU make should be installed by selecting appropriate package during
+  cygwin
+  installation.
+- Python3 `(native Windows version) <https://www.python.org/downloads/>`__ and
+  the pip package manager (from Python 3.4 it's included)
+- Python3 packages: *cryptography, pyasn1, yaml, jinja2 v2.10, cbor v1.0.0*
+
+  .. code-block:: bash
+
+    pip3 install --user cryptography pyasn1 pyyaml jinja2 cbor
+
+- `SRecord v1.63 <https://sourceforge.net/projects/srecord/>`__ (for Musca test
+  chip boards)
+
+Setup Cygwin to enable a compiler toolchain and CMake after installation.
+-------------------------------------------------------------------------
+
+If applicable, import Arm Compiler v6.10 in your shell console. To make this
+change permanent, add the command line into ~/.bashrc
+
+Armclang + DS-5
+^^^^^^^^^^^^^^^
+.. Note::
+
+    - Arm compiler specific environment variable may need updating based on
+      specific products and licenses as explained in
+      `product-and-toolkit-configuration <https://developer.arm.com/products/software-development-tools/license-management/resources/product-and-toolkit-configuration>`__.
+    - Arm licensing related environment variables must use Windows paths, and not
+      the Cygwin specific one relative to */cygrive*.
+
+.. code-block:: bash
+
+    export PATH=/cygdrive/c/<DS-5_PATH>/sw/ARMCompiler6.10/bin:$PATH
+    export ARM_PRODUCT_PATH=C:/<DS-5_PATH>/sw/mappings
+    export ARM_TOOL_VARIANT=ult
+    export ARMLMD_LICENSE_FILE=<LICENSE_FILE_PATH>
+
+Armclang + Keil MDK Arm
+^^^^^^^^^^^^^^^^^^^^^^^
+
+.. Note::
+
+    - Arm compiler specific environment variable may need updating based
+      on specific products and licenses as explained in
+      `product-and-toolkit-configuration <https://developer.arm.com/products/software-development-tools/license-management/resources/product-and-toolkit-configuration>`__.
+
+.. code-block:: bash
+
+    export PATH=/cygdrive/c/<uVision path>/ARM/ARMCLANG/bin:$PATH
+
+GNU Arm
+^^^^^^^
+
+If applicable, import GNU Arm compiler v6.3.1 in your shell console. To make
+this change permanent, add the command line into ~/.bashrc
+
+.. code-block:: bash
+
+    export PATH=<GNU Arm path>/bin:$PATH
+
+CMake
+^^^^^
+
+To import CMake in your bash shell console:
+
+.. code-block:: bash
+
+    export PATH=/cygdrive/c/<CMake path>/bin:$PATH
+
+Building the documentation
+==========================
+
+The build system is prepared to support generation of two documents.
+The Reference Manual which is Doxygen based, and the User Guide which is
+Sphinx based. Both document can be generated in HTML and PDF format.
+
+.. Note::
+
+    Support for document generation in the build environment is not mandatory.
+    Missing document generation tools will not block building the TF-M
+    firmware.
+
+To compile the TF-M Reference Manual
+------------------------------------
+
+The following additional tools are needed:
+
+    - Doxygen v1.8.0 or later
+    - Graphviz dot v2.38.0 or later
+    - PlantUML v1.2018.11 or later
+    - Java runtime environment 1.8 or later (for running PlantUML)
+
+For PDF generation the following tools are needed in addition to the
+above list:
+
+    - LaTeX
+    - PdfLaTeX
+
+Set-up the needed tools
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Linux
+"""""
+.. code-block:: bash
+
+    sudo apt-get install -y doxygen graphviz default-jre
+    mkdir ~/plantuml
+    curl -L http://sourceforge.net/projects/plantuml/files/plantuml.jar/download --output ~/plantuml/plantuml.jar
+
+For PDF generation:
+
+.. code-block:: bash
+
+    sudo apt-get install -y doxygen-latex
+
+Windows + Cygwin
+""""""""""""""""
+
+Download and install the following tools:
+    - `Doxygen
+      1.8.8 <https://sourceforge.net/projects/doxygen/files/snapshots/doxygen-1.8-svn/windows/doxygenw20140924_1_8_8.zip/download>`__
+    - `Graphviz
+      2.38 <https://graphviz.gitlab.io/_pages/Download/windows/graphviz-2.38.msi>`__
+    - The Java runtime is part of the DS5 installation or can be
+      `downloaded from here <https://www.java.com/en/download/>`__
+    - `PlantUML <http://sourceforge.net/projects/plantuml/files/plantuml.jar/download>`__
+
+For PDF generation:
+
+    -  `MikTeX <https://miktex.org/download>`__
+
+    .. Note::
+        When building the documentation the first time, MikTeX might prompt for
+        installing missing LaTeX components. Please allow the MikTeX package
+        manager to set-up these.
+
+Configure the shell
+^^^^^^^^^^^^^^^^^^^
+
+Linux
+"""""
+
+::
+
+    export PLANTUML_JAR_PATH=~/plantuml/plantuml.jar
+
+Windows + Cygwin
+""""""""""""""""
+
+Assumptions for the settings below:
+
+    - plantuml.jar is available at c:\\plantuml\\plantuml.jar
+    - doxygen, dot, and MikTeX binaries are available on the PATH.
+    - Java JVM is used from DS5 installation.
+
+::
+
+    export PLANTUML_JAR_PATH=c:/plantuml/plantuml.jar
+    export PATH=$PATH:/cygdrive/c/<DS-5 path>/sw/java/bin
+
+To compile the TF-M User Guide
+------------------------------
+
+The following additional tools are needed:
+
+    - Python3 and the following modules:
+    - Sphinx v1.7.9
+    - m2r v0.2.0
+    - sphinxcontrib-plantuml
+    - sphinx-rtd-theme
+    - Graphviz dot v2.38.0 or later
+    - PlantUML v1.2018.11 or later
+    - Java runtime environment 1.8 or later (for running PlantUML)
+
+For PDF generation the following tools are needed in addition to the
+above list:
+
+    - LaTeX
+    - PdfLaTeX
+
+Set-up the needed tools
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Linux
+"""""
+
+.. code-block:: bash
+
+    sudo apt-get install -y python3 graphviz default-jre
+    pip --user install m2r Sphinx sphinx-rtd-theme sphinxcontrib-plantuml
+    mkdir ~/plantuml
+    curl -L http://sourceforge.net/projects/plantuml/files/plantuml.jar/download --output ~/plantuml/plantuml.jar
+
+For PDF generation:
+
+.. code-block:: bash
+
+    sudo apt-get install -y doxygen-latex
+
+Windows + Cygwin
+""""""""""""""""
+Download and install the following tools:
+    - Python3 `(native Windows version) <https://www.python.org/downloads/>`__
+    - Pip packages *m2r, Sphinx, sphinx-rtd-theme sphinxcontrib-plantuml*
+
+      .. code-block:: bash
+
+        pip --user install m2r Sphinx sphinx-rtd-theme sphinxcontrib-plantuml
+
+    - `Graphviz 2.38 <https://graphviz.gitlab.io/_pages/Download/windows/graphviz-2.38.msi>`__
+    - The Java runtime is part of the DS5 installation or can be
+      `downloaded from here <https://www.java.com/en/download/>`__
+    - `PlantUML <http://sourceforge.net/projects/plantuml/files/plantuml.jar/download>`__
+
+For PDF generation:
+
+-  `MikTeX <https://miktex.org/download>`__
+
+.. Note::
+     When building the documentation the first time, MikTeX might
+     prompt for installing missing LaTeX components. Please allow the MikTeX
+     package manager to set-up these.
+
+Configure the shell
+^^^^^^^^^^^^^^^^^^^
+
+Linux
+"""""
+.. code-block:: bash
+
+    export PLANTUML_JAR_PATH=~/plantuml/plantuml.jar
+
+Windows + Cygwin
+""""""""""""""""
+
+Assumptions for the settings below:
+
+    - plantuml.jar is available at c:\\plantuml\\plantuml.jar
+    - doxygen, dot, and MikTeX binaries are available on the PATH.
+    - Java JVM is used from DS5 installation.
+
+.. code-block:: bash
+
+    export PLANTUML_JAR_PATH=c:/plantuml/plantuml.jar
+    export PATH=$PATH:/cygdrive/c/<DS-5 path>/sw/java/bin
+
+**************************
+Tool & Dependency overview
+**************************
+
+To build the TF-M firmware the following tools are needed:
+
+.. csv-table:: Tool dependencies
+   :header: "Name", "Version", "Component"
+
+   "C compiler",See `Supported C compilers`_,"Firmware"
+   "CMake",See `Supported CMake versions`_,
+   "GNU Make",See `Supported GNU make versions`_,
+   "CMSIS 5",See `External dependencies`_,
+   "mbed-crypto",See `External dependencies`_,
+   "Python",3.x,"Firmware, User Guide"
+   "yaml",,"Firmware"
+   "pyasn1",,"Firmware"
+   "jinja2",,"Firmware"
+   "cryptography",,"Firmware"
+   "cbor",,"Firmware"
+   "Doxygen",">1.8","Reference manual"
+   "Sphinx",">1.4","User Guide"
+   "sphinxcontrib-plantuml",,"User Guide"
+   "sphinx-trd-theme",,"User Guide"
+   "Git",,
+   "PlantUML",">v1.2018.11","Reference Manual, User Guide"
+   "Graphviz dot",">v2.38.0","Reference manual"
+   "Java runtime environment (JRE)",">1.8","Reference Manual, User Guide"
+   "LaTex",,"pdf version of Reference Manual and User Guide"
+   "PdfLaTex",,"pdf version of Reference Manual and User Guide"
+
+Dependency chain:
+
+.. uml::
+
+   @startuml
+    skinparam state {
+      BackgroundColor #92AEE0
+      FontColor black
+      FontSize 16
+      AttributeFontColor black
+      AttributeFontSize 16
+      BackgroundColor<<pdf>> #A293E2
+      BackgroundColor<<doc>> #90DED6
+    }
+    state fw as "Firmware" : TF-M binary
+    state c_comp as "C Compiler" : C99
+    state gmake as "GNU make"
+    state u_guide as "User Guide" <<doc>>
+    state refman as "Reference Manual" <<doc>>
+    state rtd_theme as "sphinx-rtd-theme" <<doc>>
+    state sphnix_puml as "sphinxcontrib-plantuml" <<doc>>
+    state JRE as "JRE" <<doc>> : Java Runtime Environment
+    state gwiz as "Graphwiz dot" <<doc>>
+    state Sphinx as "Sphinx" <<doc>>
+    state m2r as "m2r" <<doc>>
+    state PlantUML as "PlantUML" <<doc>>
+    state LaTex as "LaTex" <<pdf>>
+    state PdfLaTex as "PdfLaTex" <<<<pdf>>>>
+    state Doxygen as "Doxygen" <<doc>>
+
+    [*] --> fw
+    fw --> c_comp
+    fw --> CMake
+    CMake --> gmake
+    fw --> cryptography
+    fw --> pyasn1
+    fw --> yaml
+    fw --> jinja2
+    fw --> cbor
+    cryptography --> Python3
+    pyasn1 --> Python3
+    yaml --> Python3
+    jinja2 --> Python3
+    cbor --> Python3
+
+    [*] --> u_guide
+    u_guide --> Sphinx
+    Sphinx --> m2r
+    Sphinx --> rtd_theme
+    Sphinx --> sphnix_puml
+    m2r --> Python3
+    rtd_theme --> Python3
+    sphnix_puml --> Python3
+    Sphinx --> PlantUML
+    PlantUML --> JRE
+    PlantUML --> gwiz
+    Sphinx --> LaTex
+    LaTex --> PdfLaTex
+
+    [*] --> refman
+    refman --> Doxygen
+    Doxygen --> PlantUML
+    Doxygen --> LaTex
+    state Legend {
+      state x as "For PDF generation only" <<pdf>>
+      state y as "For document generation only" <<doc>>
+      state z as "Mandatory"
+    }
+
+   @enduml
+
+--------------
+
+*Copyright (c) 2017-2020, Arm Limited. All rights reserved.*