Files
u-boot/doc/board/qualcomm/board.rst
Luca Weiss 41e2de28c0 doc: board/qualcomm: Add example for boot image version 2
As required e.g. on Fairphone 5, add an example how to use boot image
with header version 2.

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Reviewed-by: Casey Connolly <casey.connolly@linaro.org>
Link: https://lore.kernel.org/r/20250611-qualcomm-doc-update-v1-3-5cf8cd94974d@fairphone.com
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>
2025-06-24 07:54:51 -06:00

136 lines
3.9 KiB
ReStructuredText

.. SPDX-License-Identifier: GPL-2.0+
.. sectionauthor:: Dzmitry Sankouski <dsankouski@gmail.com>
Qualcomm generic boards
=======================
About this
----------
This document describes how to build and run U-Boot for Qualcomm generic
boards. Right now the generic target supports the Snapdragon 845 SoC, however
it's expected to support more SoCs going forward.
SDM845 - high-end qualcomm chip, introduced in late 2017.
Mostly used in flagship phones and tablets of 2018.
The current boot flow support loading u-boot as an Android boot image via
Qualcomm's UEFI-based ABL (Android) Bootloader. The DTB used by U-Boot will
be appended to the U-Boot image the same way as when booting Linux. U-Boot
will then retrieve the DTB during init. This way the memory layout and KASLR
offset will be populated by ABL.
Installation
------------
Build
^^^^^
We will build ``u-boot-nodtb.bin`` from the u-boot source tree.
Generate FIT image (optional)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
See doc/uImage.FIT for more details
Pack android boot image
^^^^^^^^^^^^^^^^^^^^^^^
We'll assemble android boot image with ``u-boot-nodtb.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.
Boards
------
starqlte
^^^^^^^^
The starqltechn is a production board for Samsung S9 (SM-G9600) phone,
based on the Qualcomm SDM845 SoC.
This device is supported by the common qcom_defconfig.
The DTB is called "sdm845-samsung-starqltechn.dtb"
More information can be found on the `Samsung S9 page`_.
dragonboard845c
^^^^^^^^^^^^^^^
The dragonboard845c is a Qualcomm Robotics RB3 Development Platform, based on
the Qualcomm SDM845 SoC.
This device is supported by the common qcom_defconfig
The DTB is called "sdm845-db845c.dtb"
More information can be found on the `DragonBoard 845c page`_.
qcs404-evb
^^^^^^^^^^
The QCS404 EvB is a Qualcomm Development Platform, based on the Qualcomm QCS404 SoC.
This device is supported by the common qcom_defconfig
The DTB is called "qcs404-evb-4000.dtb"
Building steps
--------------
Steps:
- Build u-boot
Use the following commands::
make CROSS_COMPILE=aarch64-linux-gnu- O=.output qcom_defconfig
make CROSS_COMPILE=aarch64-linux-gnu- O=.output -j$(nproc)
Or for db410c (and other boards not supported by the generic target)::
make CROSS_COMPILE=aarch64-linux-gnu- O=.output dragonboard410c_defconfig
make CROSS_COMPILE=aarch64-linux-gnu- O=.output -j$(nproc)
Or for smartphones::
make CROSS_COMPILE=aarch64-linux-gnu- O=.output qcom_defconfig qcom-phone.config
make CROSS_COMPILE=aarch64-linux-gnu- O=.output -j$(nproc)
- gzip u-boot::
gzip u-boot-nodtb.bin
- Append dtb to gzipped u-boot::
cat u-boot-nodtb.bin.gz arch/arm/dts/your-board.dtb > u-boot-nodtb.bin.gz-dtb
- If you chose to build a FIT image, A ``qcom.its`` file can be found in ``board/qualcomm/generic/``
directory. It expects a folder as ``qcom_imgs/`` in the main directory containing pre-built kernel,
dts and ramdisk images. See ``qcom.its`` for full path to images::
mkimage -f qcom.its qcom.itb
- Now we've got everything to build android boot image::
mkbootimg --kernel u-boot-nodtb.bin.gz-dtb --ramdisk db845c.itb \
--output boot.img --pagesize 4096 --base 0x80000000
Or with no FIT image::
mkbootimg --kernel u-boot-nodtb.bin.gz-dtb \
--output boot.img --pagesize 4096 --base 0x80000000
Other devices with boot image version 2 can be built like this example::
mkbootimg --pagesize 4096 --header_version 2 \
--kernel_offset 0x00008000 --kernel u-boot-nodtb.bin.gz \
--dtb_offset 0x01f00000 --dtb dts/upstream/src/arm64/qcom/qcm6490-fairphone-fp5.dtb \
--output boot.img
- Flash boot.img using fastboot and erase dtbo to avoid conflicts with our DTB:
.. code-block:: bash
fastboot flash boot boot.img
fastboot erase dtbo
.. _Samsung S9 page: https://en.wikipedia.org/wiki/Samsung_Galaxy_S9
.. _DragonBoard 845c page: https://www.96boards.org/product/rb3-platform/