Crosscompile qt6wayland for aarch64/imx8 using cmake

MAWE · wrote on 2 Feb 2024, 12:31

I try to crosscompile qt6 to an imx8 based platform. I add the script/toolchain.cmake/patch file at the end of this post.

The first steps are working well but when cross building qtwayland I always hit this error message from cmake

-- The CXX compiler identification is GNU 12.3.0
-- The C compiler identification is GNU 12.3.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /home/mweisser/projects/sd/MCP/Devices/MCPJ/../../../../os/toolchain/linux/12/aarch64-gs-linux-gnu/bin/aarch64-gs-linux-gnu-g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /home/mweisser/projects/sd/MCP/Devices/MCPJ/../../../../os/toolchain/linux/12/aarch64-gs-linux-gnu/bin/aarch64-gs-linux-gnu-gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
CMake Error at CMakeLists.txt:16 (find_package):
  Could not find a package configuration file provided by "Qt6" (requested
  version 6.6.1) with any of the following names:

    Qt6Config.cmake
    qt6-config.cmake

  Add the installation prefix of "Qt6" to CMAKE_PREFIX_PATH or set "Qt6_DIR"
  to a directory containing one of the above files.  If "Qt6" provides a
  separate development package or SDK, be sure it has been installed.

Is anyone out there who was able to compile a qt submodule using cmake? I tried a lot of approaches found here and on the web like
https://forum.qt.io/topic/139492/qt6-cross-compile-for-imx6-with-wayland-support
https://wiki.qt.io/Cross-Compile_Qt_6_for_Raspberry_Pi
https://www.tal.org/tutorials/building-qt-65-sub-modules
but nothing works with sometimes different error messages. Any help would be greatly appreciated.

This is the script I currently use:

#!/bin/bash

set -e

BUILDBASE=$HOME/tmp/qt
mkdir -p $BUILDBASE

export TCBASE=$WORKSPACE/../../../../os/toolchain/linux/12/aarch64-gs-linux-gnu
export TCSYSROOT=$WORKSPACE/install/linux/armv8/sysroot-imx8x

#cleanup
if [[ true == true ]]; then
    rm -rf build-* host-qt target-qt qtbase-* qtwayland-*
fi

#Get the source files
cd $BUILDBASE
if [[ true == true ]]; then

    if [[ ! -f "qtbase-everywhere-src-6.6.1.tar.xz" ]]; then
        wget https://download.qt.io/official_releases/qt/6.6/6.6.1/submodules/qtbase-everywhere-src-6.6.1.tar.xz    
    fi
    tar xavf qtbase-everywhere-src-6.6.1.tar.xz
    git apply --verbose qt6.patch

    if [[ ! -f "qtwayland-everywhere-src-6.6.1.tar.xz" ]]; then
        wget https://download.qt.io/official_releases/qt/6.6/6.6.1/submodules/qtwayland-everywhere-src-6.6.1.tar.xz
    fi
    tar xavf qtwayland-everywhere-src-6.6.1.tar.xz
fi


#Build Qt6 base for host
cd $BUILDBASE
if [[ true == true ]]; then

    rm -rf build-base-host
    mkdir -p build-base-host
    cd build-base-host

    cmake -GNinja \
    -DCMAKE_BUILD_TYPE=Release \
    -DQT_BUILD_EXAMPLES=OFF \
    -DQT_BUILD_TESTS=OFF \
    -DCMAKE_INSTALL_PREFIX=$BUILDBASE/host-qt \
    -S $BUILDBASE/qtbase-everywhere-src-6.6.1

    ninja install
fi

#Build Qt6 wayland for host
cd $BUILDBASE
if [[ true == true ]]; then

    rm -rf build-wayland-host
    mkdir -p build-wayland-host
    cd build-wayland-host

    cmake -GNinja \
    -DCMAKE_INSTALL_PREFIX=$BUILDBASE/host-qt \
    -S $BUILDBASE/qtwayland-everywhere-src-6.6.1
    ninja install
fi

#Build Qt6 base for target
cd $BUILDBASE
if [[ true == true ]]; then

    rm -rf build-base-target
    mkdir -p build-base-target
    cd build-base-target

    cmake -GNinja \
    -DCMAKE_TOOLCHAIN_FILE=$BUILDBASE/toolchain.cmake \
    -DCMAKE_BUILD_TYPE=Release \
    -DINPUT_opengl=es2 \
    -DFEATURE_vulkan=OFF \
    -DFEATURE_linuxfb=OFF \
    -DFEATURE_eglfs=OFF \
    -DQT_BUILD_EXAMPLES=OFF \
    -DQT_BUILD_TESTS=OFF \
    -DQT_QMAKE_TARGET_MKSPEC=devices/linux-gsimx8x-g++ \
    -DCMAKE_INSTALL_PREFIX=$BUILDBASE/target-qt \
    -DQT_HOST_PATH=$BUILDBASE/host-qt \
    -S $BUILDBASE/qtbase-everywhere-src-6.6.1
    
    ninja install
fi

#Build Qt6 wayland for target
cd $BUILDBASE
if [[ true == true ]]; then

    rm -rf build-wayland-target
    mkdir -p build-wayland-target
    cd build-wayland-target

    cmake -GNinja \
    -DCMAKE_TOOLCHAIN_FILE=$BUILDBASE/toolchain.cmake \
    -DCMAKE_INSTALL_PREFIX=$BUILDBASE/target-qt \
    -DQT_HOST_PATH=$BUILDBASE/host-qt \
    -S $BUILDBASE/qtwayland-everywhere-src-6.6.1
    ninja install
fi

This the toolchain.cmake file

set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR aarch64)
set(CMAKE_C_COMPILER $ENV{TCBASE}/bin/aarch64-gs-linux-gnu-gcc)
set(CMAKE_CXX_COMPILER $ENV{TCBASE}/bin/aarch64-gs-linux-gnu-g++)
set(CMAKE_SYSROOT $ENV{TCSYSROOT})
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

And this my patch for the device support

diff -N -u -r diff/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qmake.conf src/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qmake.conf
--- diff/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qmake.conf	1970-01-01 01:00:00.000000000 +0100
+++ src/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qmake.conf	2023-03-13 16:30:35.102872758 +0100
@@ -0,0 +1,37 @@
+#
+# qmake configuration for the NXP i.MX8 based boards (64-bit)
+#
+# The configuration below is set up for running with the fbdev-style
+# Vivante graphics stack. (so eglfs with the eglfs_viv backend, no
+# direct drm use via eglfs_kms)
+
+# Wayland should also be functional. However, when writing Wayland
+# *compositors* with Qt, the eglfs backend will have to be switched to
+# eglfs_viv_wl by setting the QT_QPA_EGLFS_INTEGRATION environment
+# variable.
+#
+# Below is an example configure line that assumes there is an AArch64
+# toolchain and sysroot available in $HOME/imx8. On device Qt is
+# expected to be placed under /usr/local/qt514 whereas on the host
+# 'make install' will copy the host tools and the target libraries to
+# $HOME/imx8/qt5.
+#
+# ./configure -release -opengl es2 -device linux-imx8-g++ \
+#   -device-option CROSS_COMPILE=~/imx8/toolchain/x86_64-pokysdk-linux/usr/bin/aarch64-poky-linux/aarch64-poky-linux- \
+#   -sysroot ~/imx8/sysroot \
+#   -opensource -confirm-license -make libs -prefix /usr/local/qt514 -extprefix ~/imx8/qt5 -v
+
+include(../common/linux_device_pre.conf)
+
+QMAKE_LIBS_EGL         += -lEGL
+QMAKE_LIBS_OPENGL_ES2  += -lGLESv2 -lEGL -lGAL
+QMAKE_LIBS_OPENVG      += -lOpenVG -lEGL -lGAL
+
+QMAKE_CFLAGS           += -march=armv8-a -mtune=cortex-a35 -DLINUX=1 -DEGL_API_FB
+QMAKE_CXXFLAGS         += -march=armv8-a -mtune=cortex-a35 -DLINUX=1 -DEGL_API_FB
+
+DISTRO_OPTS += aarch64
+
+include(../common/linux_arm_device_post.conf)
+
+load(qt_config)
diff -N -u -r diff/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qplatformdefs.h src/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qplatformdefs.h
--- diff/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qplatformdefs.h	1970-01-01 01:00:00.000000000 +0100
+++ src/qtbase-everywhere-src-6.6.1/mkspecs/devices/linux-gsimx8x-g++/qplatformdefs.h	2023-03-13 16:27:31.874515218 +0100
@@ -0,0 +1,40 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the qmake spec of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "../../linux-g++/qplatformdefs.h"