docs(linux): U-Boot: Falcon-Mode: add non-yocto users section

Falcon mode is the U-Boot feature and not specific to our yocto distro.
Therefore document the usage of the feature for non-yocto users who
would have to run the commands implemented by `ti-falcon` override
manually.

Signed-off-by: Anshul Dalal <anshuld@ti.com>

Author: ArchUsr64

source/linux/Foundational_Components/U-Boot/UG-Falcon-Mode.rst

@@ -123,6 +123,7 @@ partition and write ``tiboot3.bin`` to the correct offset.
 For more information check: :ref:`How to flash eMMC and boot with eMMC Boot
 <how-to-emmc-boot>`.
 
+.. _u-boot_falcon_mode_fitImage_creation:
 Custom fitImage creation:
 =========================
 
@@ -188,6 +189,57 @@ Sign the kernel and dtb with ``secure-binary-image.sh`` and create the
    $ ./scripts/secure-binary-image.sh falcon.dtb falcon.dtb.sec
    $ mkimage -f fitImage.its fitImage
 
+****************
+Non-Yocto Users:
+****************
+
+Follow the steps below to build ``tiboot3.bin``, ``tifalcon.bin`` and the
+``fitImage`` required for falcon mode:
+
+#. For :ref:`ATF build <foundational-components-atf>`, use the following
+   arguments to update the ATF's jump address for the kernel and the
+   device-tree: ``PRELOADED_BL33_BASE=0x82000000 K3_HW_CONFIG_BASE=0x88000000``.
+
+#. For :ref:`R5 U-Boot build <Build-U-Boot-label>`, use the
+   ``k3_r5_falcon.config`` fragment to enable flacon support at the R5 SPL
+   stage.
+
+#. Refer to the :ref:`fitImage creation step
+   <u-boot_falcon_mode_fitImage_creation>` above for preparing a bootable
+   ``fitImage`` with an appropriate kernel and DTB.
+
+#. Copy the files generated to correct path on SD/eMMC as per the table below:
+
+   .. list-table::
+      :widths: 8 8 8 25
+      :header-rows: 1
+
+      * - File
+        - Destination path on SD/eMMC
+        - Partition
+        - Description
+
+      * - ``tiboot3.bin``
+        - ``/tiboot3.bin``
+        - boot (fat)
+        - R5 SPL with falcon support
+
+      * - ``tifalcon.bin``
+        - ``/boot/tifalcon.bin``
+        - rootfs (ext4)
+        - tispl binary without SPL for the A core and DTB
+
+      * - ``fitImage``
+        - ``/boot/fitImage``
+        - rootfs (ext4)
+        - kernel and dtb fitImage with pre-signed binaries
+
+.. note::
+
+   The ``tifalcon.bin`` binary is generated by default for all falcon
+   supported platforms at the A-Core U-Boot build step and can be found
+   alongside the existing ``tispl.bin`` file in U-Boot build's output directory.
+
 **********************
 Boot time comparisons:
 **********************