交叉编译 Qt5 armv8(aarch64) with WebEngine - NVIDIA JETSON TX2

本文写于 2020 年初，完成 armv8 下交叉编译 webengine

我的平台：On Windows10 WSL2 Debian
（注：Ubuntu <= 16.04 会出现 libclang < 3.8 的问题）

---

下载源码

为避免网络问题，先安装一个下载工具，使用aria2可以断点继续下载

sudo apt install aria2

然后 cd 到一个工作目录
Qt 5.12.5 源码

aria2c https://mirrors.tuna.tsinghua.edu.cn/qt/official_releases/qt/5.12/5.12.5/single/qt-everywhere-src-5.12.5.tar.xz
tar xf qt-everywhere-src-5.12.5.tar.xz

交叉编译工具 Linaro GCC

aria2c https://releases.linaro.org/components/toolchain/binaries/latest-5/aarch64-linux-gnu/gcc-linaro-5.5.0-2017.10-x86_64_aarch64-linux-gnu.tar.xz
tar xf gcc-linaro-5.5.0-2017.10-x86_64_aarch64-linux-gnu.tar.xz

在目标平台安装依赖

库

sudo apt-get install '.*libxcb.*' libxrender-dev libxi-dev \
    libfontconfig1-dev libudev-dev libxkbcommon-dev \
    libxkbcommon-x11-dev libc6-dev-arm64-cross libnss3-dev libicu-dev \
    libdbus-1-dev

GLES 和 EGL

mkdir /home/nvidia/GLES
cd /home/nvidia/GLES
apt-get download libgles2-mesa-dev
ar x libgles2*.deb
tar -xvf data.tar.xz
mkdir /home/nvidia/EGL
cd /home/nvidia/EGL
apt-get download libegl1-mesa-dev
ar x libegl1*.deb
tar -xvf data.tar.xz
cd /home/nvidia/GLES/usr/include
sudo cp -r GLES2 GLES3 /usr/include
cd /home/nvidia/EGL/usr/include
sudo cp -r EGL KHR /usr/include

在本机安装依赖

sudo apt-get install -y 'libxcb.*' \
    libx11-xcb-dev libglu1-mesa-dev \
    libxrender-dev libxi-dev libinput* \
    mtdev* mesa-utils \
    mesa-utils-extra libgles2-mesa-dev ninja-build \
    git rsync pkg-config gcc g++ 

ps:

以上依赖可能不全，如果 confugre 后提示 xxx 找不到，例如 xxx 找不到

通常可以直接 apt install libxxx-dev

有的库可能带有版本号，例如 libnss3-dev,可以使用 apt search xxx 搜索

安装后重新来一遍下面的全部内容

从目标平台拷贝依赖

这里的 ip 换成自己的 ip

rsync -avz -e ssh nvidia@192.168.12.232:/lib/aarch64-linux-gnu lib
rsync -avz -e ssh nvidia@192.168.12.232:/usr/include usr
rsync -avz -e ssh nvidia@192.168.12.232:/usr/lib usr
rsync -avz -e ssh nvidia@192.168.12.232:/usr/libaarch64-linux-gnu usr
rsync -avz -e ssh nvidia@192.168.12.232:/usr/aarch64-linux-gnu usr

因为有一些依赖实际上是一个symbol link，所以要替换路径

wget https://raw.githubusercontent.com/riscv/riscv-poky/master/scripts/sysroot-relativelinks.py
chmod +x sysroot-relativelinks.py
./sysroot-relativelinks.py PATH_TO_YOUR_DIR

如果链接不到raw.githubusercontent.com建一个python脚本mkdir sysroot-relativelinks.py && chomod +x sysroot-relativelinks.py && vim sysroot-relativelinks.py:

#!/usr/bin/env python
import sys
import os

# Take a sysroot directory and turn all the abolute symlinks and turn them into
# relative ones such that the sysroot is usable within another system.

if len(sys.argv) != 2:
    print("Usage is " + sys.argv[0] + "<directory>")
    sys.exit(1)

topdir = sys.argv[1]
topdir = os.path.abspath(topdir)

def handlelink(filep, subdir):
    link = os.readlink(filep)
    if link[0] != "/":
        return
    if link.startswith(topdir):
        return
    #print("Replacing %s with %s for %s" % (link, topdir+link, filep))
    print("Replacing %s with %s for %s" % (link, os.path.relpath(topdir+link, subdir), filep))
    os.unlink(filep)
    os.symlink(os.path.relpath(topdir+link, subdir), filep)

for subdir, dirs, files in os.walk(topdir):
    for f in files:
        filep = os.path.join(subdir, f)
        if os.path.islink(filep):
            #print("Considering %s" % filep)
            handlelink(filep, subdir)

运行 ./sysroot-relativelinks.py PATH_TO_YOUR_DIR

还要替换一个.a的库

ln -sf $PWD/usr/aarch64-linux-gnu/lib/libm.a $PWD/usr/lib/aarch64-linux-gnu/libm.a

编译

修改Qt make时include和lib的查找顺序

vim qt-everywhere-src-5.12.5/qtbase/mkspecs/devices/linux-jetson-tx1-g++/qmake.conf

注释掉 /usr/include

QMAKE_INCDIR_POST += \
#   $$[QT_SYSROOT]/usr/include \
    $$[QT_SYSROOT]/usr/include/aarch64-linux-gnu

调整LIBDIR和RPATHLIBKDIR的顺序，把/usr/lib/aarch64开头的放到/usr/lib的前面

QMAKE_LIBDIR_POST += \
    $$[QT_SYSROOT]/usr/lib/aarch64-linux-gnu \
    $$[QT_SYSROOT]/usr/lib \
    $$[QT_SYSROOT]/lib/aarch64-linux-gnu

QMAKE_RPATHLINKDIR_POST += \
    $$[QT_SYSROOT]/usr/lib/aarch64-linux-gnu/tegra \
    $$[QT_SYSROOT]/usr/lib/aarch64-linux-gnu \
    $$[QT_SYSROOT]/usr/lib \
    $$[QT_SYSROOT]/lib/aarch64-linux-gnu

替换下面的 CROSS_COMPILE 路径为自己的gcc-linaro路径

prefix为安装路径(这个目录是使用交叉编译后的程序自动寻找的QT_DIR目录，当然会被环境变量覆盖)

extprefix为编译后目标主机 Qt 的路径

hostprefix为编译出来的交叉编译工具的路径

sysroot 为刚刚同步库文件的目录

cd qt-everywhere-src-5.12.5
./configure -shared -c++std c++14 \
 -opensource -release --confirm-license -pkg-config \
 -no-use-gold-linker \
 -device linux-jetson-tx1-g++ \
 -device-option CROSS_COMPILE=/home/linger/crossbuild/gcc-linaro-5.5.0-2017.10-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu- \
 -sysroot /home/linger/crossbuild \
 -nomake examples -nomake tests \
 -prefix /home/linger/crossbuild/JetsonTX2/qt5 \
 -extprefix /home/linger/crossbuild/JetsonTX2/qt5 \
 -hostprefix /home/linger/crossbuild/JetsonTX2/qt5-host \
 -opengl es2 \
 -pch \
 -skip qtwayland \
 -skip qtscript \
 -skip qtandroidextras \
 -skip qtdoc \
 -skip qtremoteobjects \
 -skip qtlocation \
 -make libs \
 -no-gbm \
 -no-glib \
 -qt-libpng \
 -qt-libjpeg \
 -qt-harfbuzz \
 -qt-freetype \
 -qt-xcb

config完成后应没有warning和error，如果有依赖问题安装好依赖后删除config.cache重新configure

如果提示dbus有问题，在确认安装好libdbus-1-dev后
修改 DEPS/usr/lib/aarch64-linux-gnu/pkgconfig/dbus-1.pc
在 Libs 后面添加 -lpthread -lsystemd

编译安装

ps:

编译前确保(free -m)自己的内存+swap 大于 16G, 否则会在编译 chrominm 时挂掉

Linux swapfile 10G, count为大小, 目录位置没有限制，btrfs在kernel 5.0前不支持native swap

cd /var
sudo mkdir swap
sudo dd if=/dev/zero of=swapfile bs=1024 count=1024000
sudo mkswap swapfile
# 开启
sudo swapon /var/swapfile
# 关闭
sudo swapoff /var/swapfile

编译

make -j4
make install

如果编译过程中提示找不到 gn

# 需要代理：
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
# 镜像：
git clone https://source.codeaurora.org/quic/lc/chromium/tools/depot_tools
export PATH=$PATH:PATH_TO_YOUR_depot_tools

安装

cd JetsonTX2
scp -r qt5 nvidia@192.168.12.232:/usr/local

添加环境变量

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/qt5/lib
export QT_PLUGIN_PATH=/usr/local/qt5/plugins
export QML_IMPORT_PATH=/usr/local/qt5/qml
export QML2_IMPORT_PATH=/usr/local/qt5/qml
export QT5_DIR=/usr/local/qt5

编译带 WebEngine 的程序需要把 webegnineprocess 和依赖带到程序目录下

qt-everywhere-src-5.12.5/qtwebengine/src/core/release下的qtwebengine_locales文件夹、qtwebengine_resources_开头的.pak文件、icudtl.dat

如果提示：
ERROR:zygote_host_impl_linux.cc(88)] Running as root without --no-sandbox is not supported. See https://crbug.com/638180.

切换到非root用户或禁用 Sandbox：export QTWEBENGINE_DISABLE_SANDBOX=1

参考链接：

1. QtWebBrowser fails to launch with QtLauncher Demo
2. Cross-Compile the Qt Libraries for Nvidia® Jetson TX2 and Set the QtCreator Environment
3. Windows下定制编译QtWebEngine
4. https://github.com/riscv/riscv-poky
5. https://doc.qt.io/qt-5/configure-options.html
6. https://forum.qt.io/topic/99978/a-suitable-version-of-nss-could-not-be-found-cross-compile-raspberry-pi3-qt5-10-1