doc: board: colibri-imx8x: convert readme to reST

Convert README to reStructuredText format.

Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/doc/board/toradex/colibri-imx8x.rst b/doc/board/toradex/colibri-imx8x.rst
new file mode 100644
index 0000000..244e5a4
--- /dev/null
+++ b/doc/board/toradex/colibri-imx8x.rst
@@ -0,0 +1,82 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Colibri iMX8QXP V1.0B Module
+============================
+
+Quick Start
+-----------
+
+- Build the ARM trusted firmware binary
+- Get scfw_tcm.bin and ahab-container.img
+- Build U-Boot
+- Load U-Boot binary using uuu
+- Flash U-Boot binary into the eMMC
+- Boot
+
+Get and Build the ARM Trusted Firmware
+--------------------------------------
+
+.. code-block:: bash
+
+    $ git clone -b imx_4.14.78_1.0.0_ga https://source.codeaurora.org/external/imx/imx-atf
+    $ cd imx-atf/
+    $ make PLAT=imx8qxp bl31
+
+Get scfw_tcm.bin and ahab-container.img
+---------------------------------------
+.. code-block:: bash
+
+    $ wget https://github.com/toradex/meta-fsl-bsp-release/blob/
+           toradex-sumo-4.14.78-1.0.0_ga-bringup/imx/meta-bsp/recipes-
+           bsp/imx-sc-firmware/files/mx8qx-colibri-scfw-tcm.bin?raw=true
+    $ mv mx8qx-colibri-scfw-tcm.bin\?raw\=true mx8qx-colibri-scfw-tcm.bin
+    $ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-8.0.bin
+    $ chmod +x firmware-imx-8.0.bin
+    $ ./firmware-imx-8.0.bin
+
+Copy the following binaries to the U-Boot folder:
+
+.. code-block:: bash
+
+    $ cp imx-atf/build/imx8qxp/release/bl31.bin .
+    $ cp u-boot/u-boot.bin .
+
+Copy the following firmware to the U-Boot folder:
+
+.. code-block:: bash
+
+    $ cp firmware-imx-8.0/firmware/seco/ahab-container.img .
+
+Build U-Boot
+------------
+
+.. code-block:: bash
+
+   $ make colibri-imx8qxp_defconfig
+   $ make u-boot-dtb.imx
+
+Load the U-Boot Binary Using UUU
+--------------------------------
+
+Get the latest version of the universal update utility (uuu) aka ``mfgtools 3.0``:
+
+https://community.nxp.com/external-link.jspa?url=https%3A%2F%2Fgithub.com%2FNXPmicro%2Fmfgtools%2Freleases
+
+Put the module into USB recovery aka serial downloader mode, connect USB device
+to your host and execute ``uuu``:
+
+.. code-block:: bash
+
+    sudo ./uuu u-boot/u-boot-dtb.imx
+
+Flash the U-Boot Binary into the eMMC
+-------------------------------------
+
+Burn the ``u-boot-dtb.imx`` binary to the primary eMMC hardware boot area partition:
+
+.. code-block:: bash
+
+    load mmc 1:1 $loadaddr u-boot-dtb.imx
+    setexpr blkcnt ${filesize} + 0x1ff && setexpr blkcnt ${blkcnt} / 0x200
+    mmc dev 0 1
+    mmc write ${loadaddr} 0x0 ${blkcnt}
diff --git a/doc/board/toradex/index.rst b/doc/board/toradex/index.rst
index da65ad2..16b5a07 100644
--- a/doc/board/toradex/index.rst
+++ b/doc/board/toradex/index.rst
@@ -8,4 +8,5 @@
 
    apalix-imx8
    colibri_imx7
+   colibri-imx8x
    verdin-imx8mm