Re: [PATCH 6/6 v3] board: samsung: add Samsung Galaxy S9/S9+(SM-G96x0) board

[Stephan Gerhold <stephan@gerhold.net>]

Hi,

On Thu, Sep 23, 2021 at 09:57:32PM +0300, dsankouski@gmail.com wrote:
> From: Dzmitry Sankouski <dsankouski@gmail.com>
> 
> Samsung S9 SM-G9600 - Snapdragon SDM845 version of the phone,
> for China \ Hong Kong markets.
> Has unlockable bootloader, unlike SM-G960U (American market version),
> which allows running u-boot as a chain-loaded bootloader.
> 
> Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
> Cc: Ramon Fried <rfried.dev@gmail.com>
> Cc: Tom Rini <trini@konsulko.com>
> ---
> Changes for v2:
> - Create documentation file for SDM845 boards
> - Add starqltechn board documentation
> Changes for v3:
> - fix comment in starqltechn.c
> 
>  arch/arm/dts/Makefile                   |  1 +
>  arch/arm/dts/starqltechn-uboot.dtsi     | 39 ++++++++++++++++++
>  arch/arm/dts/starqltechn.dts            | 53 +++++++++++++++++++++++++
>  arch/arm/mach-snapdragon/Kconfig        | 13 ++++++
>  board/samsung/starqltechn/Kconfig       | 14 +++++++
>  board/samsung/starqltechn/MAINTAINERS   |  6 +++
>  board/samsung/starqltechn/Makefile      |  9 +++++
>  board/samsung/starqltechn/starqltechn.c | 10 +++++
>  configs/starqltechn_defconfig           | 33 +++++++++++++++
>  doc/board/qualcomm/index.rst            |  1 +
>  doc/board/qualcomm/sdm845.rst           | 38 ++++++++++++++++++
>  include/configs/starqltechn.h           | 16 ++++++++
>  12 files changed, 233 insertions(+)
>  create mode 100644 arch/arm/dts/starqltechn-uboot.dtsi
>  create mode 100644 arch/arm/dts/starqltechn.dts
>  create mode 100644 board/samsung/starqltechn/Kconfig
>  create mode 100644 board/samsung/starqltechn/MAINTAINERS
>  create mode 100644 board/samsung/starqltechn/Makefile
>  create mode 100644 board/samsung/starqltechn/starqltechn.c
>  create mode 100644 configs/starqltechn_defconfig
>  create mode 100644 doc/board/qualcomm/sdm845.rst
>  create mode 100644 include/configs/starqltechn.h
> 
> [...]
> diff --git a/doc/board/qualcomm/sdm845.rst b/doc/board/qualcomm/sdm845.rst
> new file mode 100644
> index 0000000000..cd46cbe9cf
> --- /dev/null
> +++ b/doc/board/qualcomm/sdm845.rst
> @@ -0,0 +1,38 @@
> +.. SPDX-License-Identifier: GPL-2.0+
> +.. sectionauthor:: Dzmitry Sankouski <dsankouski@gmail.com>
> +
> +Snapdragon 845
> +================
> +
> +About this
> +----------
> +This document describes the information about Qualcomm Snapdragon 845
> +supported boards and it's usage steps.
> +
> +SDM845 - hi-end qualcomm chip, introduced in late 2017.
> +Mostly used in flagship phones and tablets of 2018.
> +
> +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
> +------------
> +First, setup ``CROSS_COMPILE`` for aarch64. Then, build U-Boot for your board::
> +
> +	$ export CROSS_COMPILE=<aarch64 toolchain prefix>
> +	$ make <your board name here, see Boards section>_defconfig
> +	$ make
> +
> +This will build ``u-boot.bin`` in the configured output directory.
> +
> +Boards
> +------------
> +starqlte
> +^^^^^^^^^^^^
> +
> +The starqltechn is a production board for Samsung S9 (SM-G9600) phone,
> +based on the Qualcomm SDM845 SoC.
> +
> +More information can be found on the `Samsung S9 page`_.
> +
> +.. _Samsung S9 page: https://en.wikipedia.org/wiki/Samsung_Galaxy_S9

Can you add a short explanation here how you would install the
u-boot.bin on the Samsung S9? You say that it is loaded through an
Android boot image, but how exactly is it built?

For example, do you use an empty ramdisk, does the bootloader expect
some dt.img etc? Something similar to the DB820c README:
https://source.denx.de/u-boot/u-boot/-/blob/master/board/qualcomm/dragonboard820c/readme.txt#L32-61

This would be helpful if someone wants to install U-Boot on that phone
I think :)

Thanks!
Stephan