docs(imx9): add imx93 platform

Add i.MX9 platform introduction.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: Ic07ca394cff6a9e3e21b7a03f9c9080d3c1ef91a

docs/plat/imx9.rst

@@ -0,0 +1,60 @@
+NXP i.MX 9 Series
+==================
+
+Building on the market-proven i.MX 6 and i.MX 8 series, i.MX 9 series applications
+processors bring together higher performance applications cores, an independent
+MCU-like real-time domain, Energy Flex architecture, state-of-the-art security
+with EdgeLock® secure enclave and dedicated multi-sensory data processing engines
+(graphics, image, display, audio and voice). The i.MX 9 series, part of the EdgeVerse™
+edge computing platform, integrates hardware neural processing units across many
+members of the series for acceleration of machine learning applications at the edge
+`i.MX9 Applications Processors`_.
+
+Boot Sequence
+-------------
+
+BootROM --> SPL --> BL31 --> BL33(u-boot) --> Linux kernel
+
+How to build
+------------
+
+Build Procedure
+~~~~~~~~~~~~~~~
+
+-  Prepare AARCH64 toolchain.
+
+- Get the ELE FW image from NXP linux SDK package
+
+-  Build SPL and u-boot firstly, and get binary images: u-boot-spl.bin,
+   u-boot.bin and dtb
+
+-  Build TF-A
+
+   Build bl31:
+
+   .. code:: shell
+
+       CROSS_COMPILE=aarch64-linux-gnu- make PLAT=<Target_SoC> bl31
+
+   Target_SoC should be "imx93" for i.MX93 SoC.
+
+Deploy TF-A Images
+~~~~~~~~~~~~~~~~~~
+
+TF-A binary(bl31.bin), u-boot-spl.bin u-boot.bin, ELE FW image are combined
+together to generate a binary file called flash.bin, the imx-mkimage tool is
+used to generate flash.bin, and flash.bin needs to be flashed into SD card
+with certain offset for BOOT ROM.
+
+Reference Documentation
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Details on how to prepare, generate & deploy the boot image be found in following documents:
+
+- i.MX Linux User's Guide
+  `link <https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applications-processors:IMXLINUX>`__
+- i.MX Linux Reference Manual
+  `link <https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applications-processors:IMXLINUX>`__
+
+.. _i.MX9 Applications Processors: https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-processors/i-mx-9-processors:IMX9-PROCESSORS
+

docs/plat/index.rst

@@ -27,6 +27,7 @@ Platform Ports
    warp7
    imx8
    imx8m
+   imx9
    nxp/index
    poplar
    qemu