feat(doc): include bao config overview

Signed-off-by: Diogo21Costa <[email protected]>

source/bao_hyp/config.rst

@@ -3,7 +3,67 @@ Bao Configuration File
 
 Overview
 --------
-An overview of the configuration file options (structure overview)
+The Bao hypervisor's configuration is managed through a dedicated configuration in the form of a C
+source file. This section provides an in-depth description of the various configuration options
+available.
+
+The configuration file requires a global variable named ``config`` of the type ``struct config``,
+which contains two distinct lists: (i) a list of shared memory regions (``shmemlist``) and (ii) a
+list of VMs (``vmlist``). While the list of shared memory regions is optional and may be omitted
+from the configuration, the list of VMs is mandatory and must include at least 1 VM. Additionally,
+for each list, it is necessary to specify the list size using the parameters ``shmemlist_size`` and
+``vmlist_size``.
+
+.. code-block:: c
+
+    #include <config.h>
+
+    // Load guests' image
+    VM_IMAGE(img1_name, "/path/to/vm1/binary.bin");
+    VM_IMAGE(img2_name, "/path/to/vm2/binary.bin");
+
+    struct config config = {
+
+        // Shared memory region configuration
+        .shmemlist_size = N,
+        .shmemlist = (struct shmem[]) {
+            [0] = {/*shared memory config*/,},
+            [1] = {/*shared memory config*/,},
+            ...
+            [N] = {/*shared memory config*/,}
+        },
+
+        // Guests Configuration
+        .vmlist_size = NUM_VMs,
+        .vmlist = {
+            { /* VM 0 Config*/},
+            { /* VM 1 Config*/},
+            ...
+            { /* VM N Config*/},
+        }
+    };
+
+.. warning::
+    Inconsistencies between the specified list sizes (``shmemlist_size`` and ``vmlist_size``) and
+    the actual sizes of their respective lists, may result in unpredictable behavior. Ensure that
+    any changes made to the configuration lists' number of elements is reflected in the respective
+    list size.
+
+Before the configuration itself, it is necessary to declare the VM images using the ``VM_IMAGE``
+macro. This macro directly embeds the guest binary file into the hypervisor image. Here's an example
+usage of the ``VM_IMAGE``:
+
+.. code-block:: c
+
+  VM_IMAGE(img_name, "/path/to/VM/binary.bin");
+
+The ``VM_IMAGE`` macro has two parameters:
+
+1. The ``img_name``, an unique identifier associated with the image that will later be used to
+describe the image running on the VM (see `Guest Image`_);
+
+2. A C string with the guest image's binary file path. It can be either an absolute path or a path
+relative to the config source file.
 
 Guests Configuration
 --------------------
@@ -40,3 +100,27 @@ Coloring
 
 Shared Memory Configuration
 ---------------------------
+
+Configuration File Location
+---------------------------
+
+The configuration files for the Bao hypervisor are stored in a designated folder known as the
+configuration repository , identified by the make variable ``CONFIG_REPO``. By default, the
+``CONFIG_REPO`` is set to the ``configs`` folder located in the top-level directory of the Bao
+hypervisor. However, users have the flexibility to specify a different folder by setting the
+``CONFIG_REPO`` option in the make command during the hypervisor building process. For instance, a
+typical build command for Bao would be:
+
+.. code-block:: console
+
+    make PLATFORM=target-platform\
+         CONFIG_REPO=/path/to/config\
+         CONFIG=config-name\
+
+Considering a configuration named ``config-name``, the configuration source file can be located in
+the ``CONFIG_REPO`` directory in two formats:
+
+**1. Single C Source File**: a C source file with the name ``config-name.c``.
+
+**2. Directory Format**: a directory named ``config-name``  with a single ``config.c`` file within
+it.