doc/board/qualcomm/qcs404.rst

.. SPDX-License-Identifier: GPL-2.0+
.. sectionauthor:: Sumit Garg <sumit.garg@linaro.org>

QCS404 EVB
==========

About this
----------
This document describes the information about Qualcomm QCS404 evaluation board
and it's usage steps.

U-Boot can be used as a replacement for Qualcomm's original ABL (UEFI) bootloader.
It is loaded as an Android boot image through ABL

Installation
------------
Build
^^^^^
Setup ``CROSS_COMPILE`` for aarch64 and build U-Boot for your board::

	$ export CROSS_COMPILE=<aarch64 toolchain prefix>
	$ make qcs404evb_defconfig
	$ make

This will build ``u-boot.bin`` in the configured output directory.

Generate FIT image
^^^^^^^^^^^^^^^^^^
A ``qcs404.its`` file can be found in ``board/qualcomm/qcs404-evb/`` directory.
It expects a folder as ``qcs404_imgs/`` in the main directory containing
pre-built kernel, dts and ramdisk images. See ``qcs404.its`` for full path to
images.

- Build FIT image::

	mkimage -f qcs404-evb.its qcs404-evb.itb

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:

- create dump dtb::

	workdir=/tmp/prepare_payload
	mkdir -p "$workdir"
	cd "$workdir"
	mock_dtb="$workdir"/payload_mock.dtb

	dtc -I dts -O dtb -o "$mock_dtb" << EOF
	/dts-v1/;
	/ {
		model = "Qualcomm Technologies, Inc. QCS404 EVB 4000";
		compatible = "qcom,qcs404-evb-4000", "qcom,qcs404-evb", "qcom,qcs404";

		#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``

Now we've got everything to build android boot image:::

	mkbootimg --kernel u-boot.bin.gz-dtb \
	--ramdisk qcs404-evb.itb --pagesize 4096 \
	--base 0x80000000 --output boot.img

Flash image on qcs404-evb using fastboot method.