Re: [PATCH v2 18/32] doc: board/qualcomm: document generic targets

21 Dec 2023

On 19/12/2023 17:04, Caleb Connolly wrote:
...
Replace the board specific docs with a generic board.rst file which
documents the build/boot process for the sdm845 and qcs404 boards now
that the only differences are the DTB in use.
At the same time, create a debugging page to document some useful
snippets and tips for working with Qualcomm platforms.
Signed-off-by: Caleb Connolly caleb.connolly@linaro.org
doc/board/qualcomm/board.rst     | 119 ++++++++++++++++++++++++++++
  doc/board/qualcomm/debugging.rst |  61 +++++++++++++++
  doc/board/qualcomm/index.rst     |   4 +-
  doc/board/qualcomm/qcs404.rst    |  79 -------------------
  doc/board/qualcomm/sdm845.rst    | 162 ---------------------------------------
  5 files changed, 182 insertions(+), 243 deletions(-)

diff --git a/doc/board/qualcomm/board.rst b/doc/board/qualcomm/board.rst
new file mode 100644
index 000000000000..093048eee0a6
--- /dev/null
+++ b/doc/board/qualcomm/board.rst
@@ -0,0 +1,119 @@
+.. 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 - hi-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
+^^^^^
+Setup ``CROSS_COMPILE`` for aarch64 and build U-Boot for your board::


$ export CROSS_COMPILE=<aarch64 toolchain prefix>
$ make <your board name here, see Boards section>_defconfig
$ make

Perhaps you could also refer to buildman aswell as alternative to bare make
...



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



+Generate FIT image
+^^^^^^^^^^^^^^^^^^
+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::


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


+- 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




+- 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


+- 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/
diff --git a/doc/board/qualcomm/debugging.rst b/doc/board/qualcomm/debugging.rst
new file mode 100644
index 000000000000..1c35d1909d12
--- /dev/null
+++ b/doc/board/qualcomm/debugging.rst
@@ -0,0 +1,61 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. sectionauthor:: Caleb Connolly caleb.connolly@linaro.org



+Qualcomm debugging
+==================



+About this
+----------



+This page describes how to enable early UART and other debugging techniques
+for Qualcomm boards.



+Enable debug UART
+-----------------



+Newer boards (SDM845 and newer, those with GENI SE UART)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^



+Open ``configs/qcom_defconfig`` and add the following snippet to the bottom:


CONFIG_BAUDRATE=115200

# Uncomment to enable UART pre-relocation
CONFIG_DEBUG_UART=y
CONFIG_DEBUG_UART_ANNOUNCE=y
# This is the address of the debug-uart peripheral
# The value here is for SDM845, other platforms will vary
CONFIG_DEBUG_UART_BASE=0xa84000
# Boards older than ~2018 pre-date the GENI driver and unfortunately
# aren't supported here
CONFIG_DEBUG_UART_MSM_GENI=y
# For sdm845 this is the UART clock rate
CONFIG_DEBUG_UART_CLOCK=7372800
# Most newer boards have an oversampling value of 16 instead
# of 32, they need the clock rate to be doubled
#CONFIG_DEBUG_UART_CLOCK=14745600


+Then build as normal (don't forget to ``make qcom_defconfig``` again).



+Older boards (db410c and db820c)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^



+Open ``configs/dragonboard<BOARD>_defconfig``


CONFIG_BAUDRATE=115200
CONFIG_DEBUG_UART=y
CONFIG_DEBUG_UART_ANNOUNCE=y
# db410c - 0x78b0000
# db820c - 0x75b0000
CONFIG_DEBUG_UART_BASE=0x75b0000
CONFIG_DEBUG_UART_MSM=y
CONFIG_DEBUG_UART_CLOCK=7372800
#CONFIG_DEBUG_UART_SKIP_INIT=y

CONFIG_LOG=y
CONFIG_HEXDUMP=y
CONFIG_CMD_LOG=y
CONFIG_LOG_MAX_LEVEL=9
CONFIG_LOG_DEFAULT_LEVEL=9
CONFIG_LOGLEVEL=9


diff --git a/doc/board/qualcomm/index.rst b/doc/board/qualcomm/index.rst
index 0f9c4299569a..4955274a39bc 100644
--- a/doc/board/qualcomm/index.rst
+++ b/doc/board/qualcomm/index.rst
@@ -7,5 +7,5 @@ Qualcomm
     :maxdepth: 2
 dragonboard410c


sdm845
qcs404


board
debugging

diff --git a/doc/board/qualcomm/qcs404.rst b/doc/board/qualcomm/qcs404.rst
deleted file mode 100644
index 0cb71d97c987..000000000000
--- a/doc/board/qualcomm/qcs404.rst
+++ /dev/null
@@ -1,79 +0,0 @@
-.. 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.



-The current boot flow support loading u-boot as an Android boot image via
-Qualcomm's UEFI-based ABL (Android) Bootloader.



-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.
diff --git a/doc/board/qualcomm/sdm845.rst b/doc/board/qualcomm/sdm845.rst
deleted file mode 100644
index d3f218e835e0..000000000000
--- a/doc/board/qualcomm/sdm845.rst
+++ /dev/null
@@ -1,162 +0,0 @@
-.. 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.



-The current boot flow support loading u-boot as an Android boot image via
-Qualcomm's UEFI-based ABL (Android) Bootloader.



-Installation
-Build
-^^^^^
-Setup ``CROSS_COMPILE`` for aarch64 and 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.



-Generate FIT image
-^^^^^^^^^^^^^^^^^^
-See doc/uImage.FIT for more details



-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.



-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 "$workdir"
cd "$workdir"
mock_dtb="$workdir"/payload_mock.dtb

dtc -I dts -O dtb -o "$mock_dtb" << EOF
/dts-v1/;
/ {
memory {


	/* We expect the bootloader to fill in the size */


	reg = <0 0 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 --base 0x0 --kernel_offset 0x00008000 \
--ramdisk_offset 0x02000000 --tags_offset 0x01e00000 \
--pagesize 4096 --second_offset 0x00f00000 \
--ramdisk "$fit_image" \
--kernel u-boot.bin.gz-dtb \
-o boot.img


-- Flash image with your phone's flashing method.



-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.



-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:


.. code-block:: bash

 sudo fastboot flash boot boot.img




-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/
Overall looks good, the debug hints are nice!
Reviewed-by: Neil Armstrong neil.armstrong@linaro.org

    