doc: board: ti: k3: Add J784S4 EVM and AM69 SK documentation

TI K3 J784S4 and AM69 are new additions to the K3 SoC family.
Add documentation about the J784S4 EVM and AM69 SK.

Signed-off-by: Dasnavis Sabiya <sabiya.d@ti.com>
Signed-off-by: Apurva Nandan <a-nandan@ti.com>
Reviewed-by: Neha Malcom Francis <n-francis@ti.com>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> # AM69-SK
diff --git a/doc/board/ti/j784s4_evm.rst b/doc/board/ti/j784s4_evm.rst
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+.. SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause
+.. sectionauthor:: Apurva Nandan <a-nandan@ti.com>
+
+J784S4 and AM69 Platforms
+=========================
+
+Introduction
+------------
+The J784S4 SoC belongs to the K3 Multicore SoC architecture
+platform, providing advanced system integration in automotive,
+ADAS and industrial applications requiring AI at the network edge.
+This SoC extends the K3 Jacinto 7 family of SoCs with focus on
+raising performance and integration while providing interfaces,
+memory architecture and compute performance for multi-sensor, high
+concurrency applications.
+
+The device is partitioned into three functional domains, each containing
+specific processing cores and peripherals:
+
+1. Wake-up (WKUP) domain
+    * ARM Cortex-M4F processor, runs TI Foundational Security (TIFS)
+
+2. Microcontroller (MCU) domain
+    * Dual core ARM Cortex-R5F processor, runs device management
+      and SoC early boot
+
+3. MAIN domain
+    * Two clusters of quad core 64-bit ARM Cortex-A72, runs HLOS
+    * Dual core ARM Cortex-R5F processor used for RTOS applications
+    * Four C7x DSPs used for Machine Learning applications.
+
+
+More info can be found in TRM: http://www.ti.com/lit/zip/spruj52
+
+Platform information:
+
+* https://www.ti.com/tool/J784S4XEVM
+* https://www.ti.com/tool/SK-AM69
+
+Boot Flow
+---------
+Below is the pictorial representation of boot flow:
+
+.. image:: img/boot_diagram_k3_current.svg
+    :alt: K3 boot flow
+
+- On this platform, "TI Foundational Security" (TIFS) functions as the
+  security enclave master. While "Device Manager" (DM), also known as the
+  "TISCI server" in TI terminology, offers all the essential services.
+
+- As illustrated in the diagram above, R5 SPL manages power and clock
+  services independently before handing over control to DM. The A72 or
+  the C7x (Aux core) software components request TIFS/DM to handle
+  security or device management services.
+
+Sources
+-------
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_boot_sources
+    :end-before: .. k3_rst_include_end_boot_sources
+
+Build procedure
+---------------
+0. Setup the environment variables:
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_common_env_vars_desc
+    :end-before: .. k3_rst_include_end_common_env_vars_desc
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_board_env_vars_desc
+    :end-before: .. k3_rst_include_end_board_env_vars_desc
+
+Set the variables corresponding to this platform:
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_common_env_vars_defn
+    :end-before: .. k3_rst_include_end_common_env_vars_defn
+.. code-block:: bash
+
+ $ export UBOOT_CFG_CORTEXR=j784s4_evm_r5_defconfig
+ $ export UBOOT_CFG_CORTEXA=j784s4_evm_a72_defconfig
+ $ export TFA_BOARD=j784s4
+ $ export TFA_EXTRA_ARGS="K3_USART=0x8"
+ $ export OPTEE_PLATFORM=k3-j784s4
+ $ export OPTEE_EXTRA_ARGS="CFG_CONSOLE_UART=0x8"
+
+.. j784s4_evm_rst_include_start_build_steps
+
+1. Trusted Firmware-A
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_build_steps_tfa
+    :end-before: .. k3_rst_include_end_build_steps_tfa
+
+
+2. OP-TEE
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_build_steps_optee
+    :end-before: .. k3_rst_include_end_build_steps_optee
+
+3. U-Boot
+
+.. _j784s4_evm_rst_u_boot_r5:
+
+* 3.1 R5
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_build_steps_spl_r5
+    :end-before: .. k3_rst_include_end_build_steps_spl_r5
+
+.. _j784s4_evm_rst_u_boot_a72:
+
+* 3.2 A72
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_build_steps_uboot
+    :end-before: .. k3_rst_include_end_build_steps_uboot
+.. j784s4_evm_rst_include_end_build_steps
+
+Target Images
+-------------
+In order to boot we need tiboot3.bin, tispl.bin and u-boot.img. Each SoC
+variant (GP, HS-FS, HS-SE) requires a different source for these files.
+
+ - GP
+
+    * tiboot3-j784s4-gp-evm.bin from :ref:`step 3.1 <j784s4_evm_rst_u_boot_r5>`
+    * tispl.bin_unsigned, u-boot.img_unsigned from :ref:`step 3.2 <j784s4_evm_rst_u_boot_a72>`
+
+ - HS-FS
+
+    * tiboot3-j784s4-hs-fs-evm.bin from :ref:`step 3.1 <j784s4_evm_rst_u_boot_r5>`
+    * tispl.bin, u-boot.img from :ref:`step 3.2 <j784s4_evm_rst_u_boot_a72>`
+
+ - HS-SE
+
+    * tiboot3-j784s4-hs-evm.bin from :ref:`step 3.1 <j784s4_evm_rst_u_boot_r5>`
+    * tispl.bin, u-boot.img from :ref:`step 3.2 <j784s4_evm_rst_u_boot_a72>`
+
+Image formats
+-------------
+
+- tiboot3.bin
+
+.. image:: img/multi_cert_tiboot3.bin.svg
+    :alt: tiboot3.bin format
+
+- tispl.bin
+
+.. image:: img/dm_tispl.bin.svg
+    :alt: tispl.bin format
+
+R5 Memory Map
+-------------
+
+.. list-table::
+   :widths: 16 16 16
+   :header-rows: 1
+
+   * - Region
+     - Start Address
+     - End Address
+
+   * - SPL
+     - 0x41c00000
+     - 0x41c40000
+
+   * - EMPTY
+     - 0x41c40000
+     - 0x41c61f20
+
+   * - STACK
+     - 0x41c65f20
+     - 0x41c61f20
+
+   * - Global data
+     - 0x41c65f20
+     - 0x41c66000
+
+   * - Heap
+     - 0x41c66000
+     - 0x41c76000
+
+   * - BSS
+     - 0x41c76000
+     - 0x41c80000
+
+   * - DM DATA
+     - 0x41c80000
+     - 0x41c84130
+
+   * - EMPTY
+     - 0x41c84130
+     - 0x41cff9fc
+
+   * - MCU Scratchpad
+     - 0x41cff9fc
+     - 0x41cffbfc
+
+   * - ROM DATA
+     - 0x41cffbfc
+     - 0x41cfffff
+
+Switch Setting for Boot Mode
+----------------------------
+
+Boot Mode pins provide means to select the boot mode and options before the
+device is powered up. After every POR, they are the main source to populate
+the Boot Parameter Tables.
+
+Boot Mode Pins for J784S4-EVM
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following tables show some common boot modes used on J784S4 EVM platform.
+More details can be found in the Technical Reference Manual:
+http://www.ti.com/lit/zip/spruj52 under the `Boot Mode Pins` section.
+
+.. list-table:: J784S4 EVM Boot Modes
+   :widths: 16 16 16
+   :header-rows: 1
+
+   * - Switch Label
+     - SW11: 12345678
+     - SW7: 12345678
+
+   * - SD
+     - 10000010
+     - 00000000
+
+   * - EMMC
+     - 10000000
+     - 01000000
+
+   * - OSPI
+     - 00000110
+     - 01000000
+
+   * - UART
+     - 00000000
+     - 01110000
+
+For SW7 and SW11, the switch state in the "ON" position = 1.
+
+Boot Mode Pins for AM69-SK
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following table show some common boot modes used on AM69-SK platform.
+More details can be found in the User Guide for AM69-SK:
+https://www.ti.com/lit/ug/spruj70/spruj70.pdf under the `Bootmode Settings`
+section.
+
+.. list-table:: AM69 SK Boot Modes
+   :widths: 16 16
+   :header-rows: 1
+
+   * - Switch Label
+     - SW2: 1234
+
+   * - SD
+     - 0000
+
+   * - EMMC
+     - 0110
+
+   * - UART
+     - 1010
+
+For SW2, the switch state in the "ON" position = 1.
+
+Debugging U-Boot
+----------------
+
+See :ref:`Common Debugging environment - OpenOCD<k3_rst_refer_openocd>`: for
+detailed setup information.
+
+.. warning::
+
+  **OpenOCD support since**: September 2023 (git master)
+
+  Until the next stable release of OpenOCD is available in your development
+  environment's distribution, it might be necessary to build OpenOCD `from the
+  source <https://github.com/openocd-org/openocd>`_.
+
+Debugging U-Boot on J784S4-EVM and AM69-SK
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. include::  k3.rst
+    :start-after: .. k3_rst_include_start_openocd_connect_XDS110
+    :end-before: .. k3_rst_include_end_openocd_connect_XDS110
+
+To start OpenOCD and connect to J784S4-EVM or AM69-SK board, use the
+following.
+
+.. code-block:: bash
+
+  openocd -f board/ti_j784s4evm.cfg
diff --git a/doc/board/ti/k3.rst b/doc/board/ti/k3.rst
index 3c33efd..15e1ed2 100644
--- a/doc/board/ti/k3.rst
+++ b/doc/board/ti/k3.rst
@@ -41,6 +41,7 @@
    ../beagle/j721e_beagleboneai64
    j721e_evm
    j721s2_evm
+   j784s4_evm
 
 Boot Flow Overview
 ------------------