doc: board: qualcomm: document Dragonwing IQ8 board building/flashing

Introducing documentation support for Qualcomm Dragonwing IQ8 QCS8300
board. Documents the build and flashing steps.

Signed-off-by: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>

doc/board/qualcomm/index.rst

@@ -6,10 +6,11 @@ Qualcomm
 .. toctree::
    :maxdepth: 2
 
-   dragonboard410c
-   rb3gen2
-   dragonwing
    board
-   phones
    debugging
+   dragonboard410c
+   dragonwing
+   rb3gen2
+   iq8
+   phones
    rdp

doc/board/qualcomm/iq8.rst

@@ -0,0 +1,43 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. sectionauthor:: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>
+
+Qualcomm DragonWing IQ8
+========================================
+
+The Dragonwing IQ8 Series (which includes QCS8300) powers computeheavy and AI-based devices, and is designed
+to operate in an expanded temperature range with available built-in safety features.
+Dragonwing IQ8 Series delivers industrial-grade AI performance of up to 40 TOPS, an octa-core
+Qualcomm Kryo Gen 6 CPU, a powerful Qualcomm Adreno 623 GPU, support for
+up to 12 concurrent cameras, and 4K video encode and decode alongside multiple displays.
+
+More information can be found on the `Qualcomm's IQ8 product page`_.
+
+.. _Qualcomm's IQ8 product page: https://docs.qualcomm.com/bundle/publicresource/87-83839-1_REV_A_Qualcomm_IQ8_Series_Product_Brief________.pdf
+
+Installation
+------------
+First, setup ``CROSS_COMPILE`` for aarch64. Then, build U-Boot for ``QCS8300``::
+
+  $ export CROSS_COMPILE=<aarch64 toolchain prefix>
+  $ make qcom_qcs8300_defconfig
+  $ make -j8 u-boot.mbn
+
+This will build the signed ``u-boot.mbn`` in the configured output directory.
+The firmware expects firmware ELF images to be "signed". The signature
+does not provide any security in this case, but it provides the firmware
+with some required metadata.
+
+Then flash the resulting ``u-boot.mbn`` to the ``uefi_a`` partition
+on your device with ``fastboot flash uefi_a u-boot.mbn``.
+
+U-Boot should be running after a reboot (``fastboot reboot``).
+
+Note that fastboot is not yet supported in U-Boot on Dragonwing IQ8, as a result, to flash
+back the original firmware, or new versoins of the U-Boot, EDL mode must be used.
+
+A tool like bkerler's `edl`_ can be used for flashing.
+
+$ edl.py --loader /path/to/prog_firehose_ddr.elf w uefi_a u-boot.mbn
+
+.. _qtestsign: https://github.com/msm8916-mainline/qtestsign
+.. _edl: https://github.com/bkerler/edl