board: qualcomm: Add support for dragonboard845c

Add support for 96Boards Dragonboard 845C aka Robotics RB3 development
platform. This board complies with 96Boards Open Platform Specifications.

Features:
- Qualcomm Snapdragon SDA845 SoC
- 4GiB RAM
- 64GiB UFS drive

U-boot is chain loaded by ABL in 64-bit mode as part of boot.img.
For detailed build and boot instructions, refer to
doc/board/qualcomm/sdm845.rst, board: dragonboard845c.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>

1 files changed, 87 insertions, 13 deletions

diff --git a/doc/board/qualcomm/sdm845.rst b/doc/board/qualcomm/sdm845.rst
index b6642c95790..8ef47492877 100644
--- a/doc/board/qualcomm/sdm845.rst
+++ b/doc/board/qualcomm/sdm845.rst
@@ -35,9 +35,25 @@ Pack android boot image
 ^^^^^^^^^^^^^^^^^^^^^^^
 We'll assemble android boot image with ``u-boot.bin`` instead of linux kernel,
 and FIT image instead of ``initramfs``. Android bootloader expect gzipped kernel
-with appended dtb, so let's mimic linux to satisfy stock bootloader:
+with appended dtb, so let's mimic linux to satisfy stock bootloader.
 
-- create dump dtb::
+Boards
+------------
+starqlte
+^^^^^^^^^^^^
+
+The starqltechn is a production board for Samsung S9 (SM-G9600) phone,
+based on the Qualcomm SDM845 SoC.
+
+Steps:
+
+- Build u-boot::
+
+	$ export CROSS_COMPILE=<aarch64 toolchain prefix>
+	$ make starqltechn_defconfig
+	$ make
+
+- Create dump dtb::
 
 	workdir=/tmp/prepare_payload
 	mkdir -p "$workdir"
@@ -56,10 +72,15 @@ with appended dtb, so let's mimic linux to satisfy stock bootloader:
 	};
 	EOF
 
-- gzip u-boot ``gzip u-boot.bin``
-- append dtb to gzipped u-boot: ``cat u-boot.bin.gz "$mock_dtb" > u-boot.bin.gz-dtb``
+- gzip u-boot::
+
+	gzip u-boot.bin
 
-Now we've got everything to build android boot image:::
+- Append dtb to gzipped u-boot::
+
+	cat u-boot.bin.gz "$mock_dtb" > u-boot.bin.gz-dtb
+
+- Now we've got everything to build android boot image::
 
 	mkbootimg --base 0x0 --kernel_offset 0x00008000 \
 	--ramdisk_offset 0x02000000 --tags_offset 0x01e00000 \
@@ -68,16 +89,69 @@ Now we've got everything to build android boot image:::
 	--kernel u-boot.bin.gz-dtb \
 	-o boot.img
 
-Flash image with your phone's flashing method.
+- Flash image with your phone's flashing method.
 
-Boards
-------------
-starqlte
-^^^^^^^^^^^^
+More information can be found on the `Samsung S9 page`_.
 
-The starqltechn is a production board for Samsung S9 (SM-G9600) phone,
-based on the Qualcomm SDM845 SoC.
+dragonboard845c
+^^^^^^^^^^^^^^^
 
-More information can be found on the `Samsung S9 page`_.
+The dragonboard845c is a Qualcomm Robotics RB3 Development Platform, based on
+the Qualcomm SDM845 SoC.
+
+Steps:
+
+- Build u-boot::
+
+	$ export CROSS_COMPILE=<aarch64 toolchain prefix>
+	$ make dragonboard845c_defconfig
+	$ make
+
+- Create dummy dtb::
+
+	workdir=/tmp/prepare_payload
+	mkdir -p "$workdir"
+	mock_dtb="$workdir"/payload_mock.dtb
+
+	dtc -I dts -O dtb -o "$mock_dtb" << EOF
+	/dts-v1/;
+	/ {
+		#address-cells = <2>;
+		#size-cells = <2>;
+
+		memory@80000000 {
+			device_type = "memory";
+			/* We expect the bootloader to fill in the size */
+			reg = <0 0x80000000 0 0>;
+		};
+
+		chosen { };
+	};
+	EOF
+
+- gzip u-boot::
+
+	gzip u-boot.bin
+
+- Append dtb to gzipped u-boot::
+
+	 cat u-boot.bin.gz "$mock_dtb" > u-boot.bin.gz-dtb
+
+- A ``db845c.its`` file can be found in ``board/qualcomm/dragonboard845c/``
+  directory. It expects a folder as ``db845c_imgs/`` in the main directory
+  containing pre-built kernel, dts and ramdisk images. See ``db845c.its``
+  for full path to images::
+
+	mkimage -f db845c.its db845c.itb
+
+- Now we've got everything to build android boot image::
+
+	mkbootimg --kernel u-boot.bin.gz-dtb --ramdisk db845c.itb \
+	--output boot.img --pagesize 4096 --base 0x80000000
+
+- Flash boot.img using db845c fastboot method.
+
+More information can be found on the `DragonBoard 845c page`_.
 
 .. _Samsung S9 page: https://en.wikipedia.org/wiki/Samsung_Galaxy_S9
+.. _DragonBoard 845c page: https://www.96boards.org/product/rb3-platform/