Re: [Buildroot] [PATCH] configs/coolpi_4b: new defconfig

[Julien Olivain <ju.o@free.fr>]

Hi Andy,

Thanks for the patch. I have comments, see below.

On 30/03/2025 10:04, Andy Yan wrote:
> CoolPi 4B is a rk3588s based SBC[0].
> Specification:
> - Rockchip RK3588S
> - LPDDR4 2/4/8/16 GB
> - TF scard slot
> - eMMC 8/32/64/128 GB module
> - Gigabit ethernet drived by PCIE with RTL8111HS
> - HDMI Type D out
> - Mini DP out
> - USB 2.0 Host x 2
> - USB 3.0 OTG x 1
> - USB 3.0 Host x 1
> - WIFI/BT module AIC8800
> - 40 pin header
> 
> Add support for it with latest mainline Linux/U-Boot.
> And also Enable network, Weston, Gstreamer packages.

This defconfig selects too many packages.
Quoting the Buildroot documentation:
https://buildroot.org/downloads/manual/manual.html#adding-board-support
"""
No specific package should be selected: the configuration should be
as minimal as possible, and should only build a working basic BusyBox
system for the target platform.
"""

You can keep hardware support (linux config fragment,
linux firmware), but gstreamer, glmark2, igt-gpu-tools, kmscube,
mesa3d, weston and openssh should be removed.

Alternatively, you can add recommendations in the readme.txt,
create your own Buildroot fork or a br2-external project
enabling all the packages you need.

> [0]https://www.cool-pi.com/product/cp4b/
> 
> Signed-off-by: Andy Yan <andyshrk@163.com>
> ---

[...]

> diff --git a/board/coolpi/coolpi-4b/post-image.sh 
> b/board/coolpi/coolpi-4b/post-image.sh
> new file mode 100755
> index 0000000000..f8f17e0716
> --- /dev/null
> +++ b/board/coolpi/coolpi-4b/post-image.sh
> @@ -0,0 +1,7 @@
> +#!/usr/bin/env bash

Running the command "utils/docker-run make check-package" reports
an error:

     board/coolpi/coolpi-4b/post-image.sh:0: run 'shellcheck' and fix the 
warnings

Could you fix those ShellCheck warnings, please?

> +set -e
> +
> +BOARD_DIR="$(dirname $0)"
> +gzip -fk "${BINARIES_DIR}/Image"
> +install -m 0644 -D $BOARD_DIR/extlinux.conf 
> $BINARIES_DIR/extlinux/extlinux.conf
> +support/scripts/genimage.sh -c board/coolpi/coolpi-4b/genimage.cfg
> diff --git a/board/coolpi/coolpi-4b/readme.txt 
> b/board/coolpi/coolpi-4b/readme.txt
> new file mode 100644
> index 0000000000..7896de50a2
> --- /dev/null
> +++ b/board/coolpi/coolpi-4b/readme.txt
> @@ -0,0 +1,66 @@
> +Cool Pi 4B
> +==============
> +https://cool-pi.com/topic/145/coolpi-4b-hardware-info
> +
> +Build:
> +======
> +  $ make coolpi_4b_defconfig
> +  $ make
> +
> +Files created in output directory
> +=================================
> +
> +output/images
> +.
> +output/images/
> +├── boot.vfat
> +├── extlinux
> +│   └── extlinux.conf
> +├── Image
> +├── Image.gz
> +├── rk3588_bl31_v1.40.elf
> +├── rk3588_ddr_lp4_2112MHz_lp5_2736MHz_v1.12.bin
> +├── rk3588s-coolpi-4b.dtb
> +├── rootfs.ext2
> +├── rootfs.ext4 -> rootfs.ext2
> +├── rootfs.tar
> +├── sdcard.img
> +├── u-boot.bin
> +└── u-boot-rockchip.bin
> +
> +Creating bootable SD card:
> +==========================
> +
> +Simply invoke (as root)
> +
> +sudo dd if=output/images/sdcard.img of=/dev/sdX && sync
> +
> +Where X is your SD card device.
> +
> +Booting:
> +========
> +
> +Serial console:
> +---------------
> +The Cool Pi 4B has a 40-pin GPIO header.
> +
> +The Uart pins are as follows:
> +
> +pin 6:  gnd
> +pin 8:  tx
> +pin 10: rx
> +
> +Baudrate for this board is 1500000.
> +
> +Login:
> +------
> +Enter 'root' as login user, and the prompt is ready.
> +
> +Network:
> +WIFI:     Cool Pi 4B has a aic8800 sdio wifi on board, but
> +          aic8800 is not supported by linux mainine yet.
> +Ethernet: A RJ-45 interface drivered by PCIE Realtek Ethernet adapter 
> R8169.
> +          So we can login it by ssh: ssh root@172.16.12.166

If openssh is removed from the defconfig, this comment
should be removed too.

> +          Remember to replace you own ip addres on this board.
> +
> +Eanble Wayland Desktop: weston --backend=drm-backend.so -i 0

Same comment for weston.

> diff --git a/board/coolpi/coolpi-4b/rootfs_overlay/etc/fstab 
> b/board/coolpi/coolpi-4b/rootfs_overlay/etc/fstab
> new file mode 100644
> index 0000000000..120a1cec02
> --- /dev/null
> +++ b/board/coolpi/coolpi-4b/rootfs_overlay/etc/fstab

The fstab can be removed. The default Buildroot skeleton provides
a minimal fstab.

> diff --git a/board/coolpi/coolpi-4b/rootfs_overlay/etc/profile 
> b/board/coolpi/coolpi-4b/rootfs_overlay/etc/profile
> new file mode 100644
> index 0000000000..4ed68310af
> --- /dev/null
> +++ b/board/coolpi/coolpi-4b/rootfs_overlay/etc/profile

This profile customization can also be removed.

> diff --git a/board/coolpi/coolpi-4b/rootfs_overlay/etc/ssh/sshd_config 
> b/board/coolpi/coolpi-4b/rootfs_overlay/etc/ssh/sshd_config
> new file mode 100644
> index 0000000000..87faf28884
> --- /dev/null
> +++ b/board/coolpi/coolpi-4b/rootfs_overlay/etc/ssh/sshd_config

This sshd_config can also be removed, since openssh will be removed.

> diff --git a/configs/coolpi_4b_defconfig b/configs/coolpi_4b_defconfig
> new file mode 100644
> index 0000000000..f4e0cd4bea
> --- /dev/null
> +++ b/configs/coolpi_4b_defconfig
> @@ -0,0 +1,78 @@
> +BR2_aarch64=y
> +BR2_cortex_a76_a55=y

The defconfigs should define a specific Kernel version.
You introduced this board DTS in Kernel v6.8, in:
https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3f5d336d64d634426b8733848d840ceb8fe96610

So I recommend to select the latest lts kernel, for example
v6.12.21. Then, you should have a config line:

BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_6_12=y

> +BR2_TOOLCHAIN_BUILDROOT_CXX=y

With the extra packages removed, I think this
BR2_TOOLCHAIN_BUILDROOT_CXX is no longer needed and can be removed.

> +BR2_DOWNLOAD_FORCE_CHECK_HASHES=y
> +BR2_TARGET_GENERIC_HOSTNAME="coolpi"
> +BR2_TARGET_GENERIC_ISSUE="Welcome to the CoolPi 4B"
> +BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV=y

With weston and other package removed, I think
BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV=y can be removed too.

> +BR2_SYSTEM_DHCP="enP4p65s0"
> +BR2_ROOTFS_OVERLAY="board/coolpi/coolpi-4b/rootfs_overlay"

If all the customization are removed, then the BR2_ROOTFS_OVERLAY
can be removed too.

> +BR2_ROOTFS_POST_IMAGE_SCRIPT="board/coolpi/coolpi-4b/post-image.sh"
> +BR2_LINUX_KERNEL=y

And also here, you should also set a specific kernel version:

BR2_LINUX_KERNEL_CUSTOM_VERSION=y
BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="6.12.21"

Note that, since you selected BR2_DOWNLOAD_FORCE_CHECK_HASHES=y
you will need to add custom hash files.

See:
https://buildroot.org/downloads/manual/manual.html#_adding_project_specific_patches_and_hashes

See also an example commit just enabling hashes:
https://gitlab.com/buildroot.org/buildroot/-/commit/4ca8f0ea762061ad04016d065f37e0c351d578f1

> +BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
> +BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="board/coolpi/coolpi-4b/linux.fragment"
> +BR2_LINUX_KERNEL_DTS_SUPPORT=y
> +BR2_LINUX_KERNEL_INTREE_DTS_NAME="rockchip/rk3588s-coolpi-4b"
> +BR2_LINUX_KERNEL_DTB_OVERLAY_SUPPORT=y

Below, the packages should be removed:
gstreamer, glmark2, igt-gpu-tools, kmscube, mesa3d-demos, mesa3d and 
weston.
Remove from here...

> +BR2_PACKAGE_GSTREAMER1=y
> +BR2_PACKAGE_GST1_PLUGINS_BASE_INSTALL_TOOLS=y
> +BR2_PACKAGE_GST1_PLUGINS_BASE_PLUGIN_APP=y
> +BR2_PACKAGE_GST1_PLUGINS_BASE_PLUGIN_VIDEOTESTSRC=y
> +BR2_PACKAGE_GST1_PLUGINS_BASE_PLUGIN_VIDEORATE=y
> +BR2_PACKAGE_GST1_PLUGINS_BASE_LIB_OPENGL=y
> +BR2_PACKAGE_GST1_PLUGINS_BAYER2RGB_NEON=y
> +BR2_PACKAGE_GST1_PLUGINS_GOOD=y
> +BR2_PACKAGE_GST1_PLUGINS_GOOD_PLUGIN_AUTODETECT=y
> +BR2_PACKAGE_GST1_PLUGINS_GOOD_PLUGIN_DEINTERLACE=y
> +BR2_PACKAGE_GST1_PLUGINS_GOOD_PLUGIN_V4L2=y
> +BR2_PACKAGE_GST1_PLUGINS_GOOD_PLUGIN_V4L2_PROBE=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_AUTOCONVERT=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_CODECALPHA=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_DEBUGUTILS=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_INTERLACE=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_MPEGDEMUX=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_MPEGTSDEMUX=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_MPEGTSMUX=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_MPEGPSMUX=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_VIDEOFILTERS=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_VIDEOPARSERS=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_VIDEOSIGNAL=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_KMS=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_V4L2CODECS=y
> +BR2_PACKAGE_GST1_PLUGINS_BAD_PLUGIN_X265=y
> +BR2_PACKAGE_GST1_LIBAV=y
> +BR2_PACKAGE_GLMARK2=y
> +BR2_PACKAGE_IGT_GPU_TOOLS=y
> +BR2_PACKAGE_KMSCUBE=y
> +BR2_PACKAGE_MESA3D_DEMOS=y
> +BR2_PACKAGE_MESA3D=y
> +BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_PANFROST=y
> +BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_SOFTPIPE=y
> +BR2_PACKAGE_MESA3D_OPENGL_EGL=y
> +BR2_PACKAGE_MESA3D_OPENGL_ES=y
> +BR2_PACKAGE_WESTON=y
> +BR2_PACKAGE_WESTON_SIMPLE_CLIENTS=y
> +BR2_PACKAGE_WESTON_DEMO_CLIENTS=y

...to here.

> +BR2_PACKAGE_LINUX_FIRMWARE=y
> +BR2_PACKAGE_LINUX_FIRMWARE_RTL_8169=y
> +BR2_PACKAGE_LINUX_FIRMWARE_ARM_MALI_CSF=y
> +BR2_PACKAGE_ROCKCHIP_RKBIN=y
> +BR2_PACKAGE_ROCKCHIP_RKBIN_TPL_FILENAME="bin/rk35/rk3588_ddr_lp4_2112MHz_lp5_2736MHz_v1.12.bin"
> +BR2_PACKAGE_ROCKCHIP_RKBIN_BL31_FILENAME="bin/rk35/rk3588_bl31_v1.40.elf"

Below, libdrm and openssh should be removed. From here...

> +BR2_PACKAGE_LIBDRM_INSTALL_TESTS=y
> +BR2_PACKAGE_OPENSSH=y

...to here.

> +BR2_TARGET_ROOTFS_EXT2=y
> +BR2_TARGET_ROOTFS_EXT2_4=y
> +BR2_TARGET_ROOTFS_EXT2_SIZE="512M"

With the removal of the packages, you can reduce the filesystem
size, if you want.

> +BR2_TARGET_UBOOT=y

Same comment for U-Boot as for the Kernel. The defconfig should define a
specific version. Since you introduced this board support upstream in
version v2024.07 in:
https://source.denx.de/u-boot/u-boot/-/commit/341f13e469063d3b8d0316f36c0d4836c74e1ac1

I recommend you add here:

BR2_TARGET_UBOOT_CUSTOM_VERSION=y
BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2025.01"

The custom hashes should also be added.

> +BR2_TARGET_UBOOT_BOARD_DEFCONFIG="coolpi-4b-rk3588s"
> +BR2_TARGET_UBOOT_NEEDS_PYLIBFDT=y
> +BR2_TARGET_UBOOT_NEEDS_PYELFTOOLS=y
> +BR2_TARGET_UBOOT_NEEDS_OPENSSL=y
> +BR2_TARGET_UBOOT_NEEDS_ROCKCHIP_RKBIN=y
> +BR2_PACKAGE_HOST_DOSFSTOOLS=y
> +BR2_PACKAGE_HOST_GENIMAGE=y
> +BR2_PACKAGE_HOST_MTOOLS=y
> +BR2_PACKAGE_HOST_PYTHON3=y

This config BR2_PACKAGE_HOST_PYTHON3=y can be removed. None of the post
build script are using python. If a package needs python, it will pull
the dependency. If the kernel needs python3, then the configuration
should be BR2_LINUX_KERNEL_NEEDS_HOST_PYTHON3=y (there is optimizations
to skip the compilation of host-python3 if a host version is usable).

> +BR2_PACKAGE_HOST_UBOOT_TOOLS=y

Could you send an updated patch addressing those comments, please?

Best regards,

Julien.
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