Cross-compile QtWebEngine for Raspberry 3

DiegOne

I am trying to cross compile QT 5.15.2 for a Raspberry Pi 3. I am following this guide: https://ebsolution31.wordpress.com/2020/10/08/cross-compile-qt/

I can cross compile qtbase, but I failed many times to cross compile qt-webengine. After the make command of the qtwebengine every times I get this error:

...
[4/13058] /home/administrator/raspi/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc -MMD -MF obj/third_party/zlib/bundled_zlib/deflate.o.d -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DOFFICIAL_BUILD -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNO_UNWIND_TABLES -DCR_SYSROOT_HASH=3fcc1d4e44127006318371002a0f421a4fde2ab4 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DZLIB_IMPLEMENTATION -DADLER32_SIMD_NEON -DINFLATE_CHUNK_SIMD_NEON -DCRC32_ARMV8_CRC32 -DARMV8_OS_LINUX -Igen -I../../3rdparty/chromium -I../../3rdparty/chromium/third_party/zlib -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -fno-unwind-tables -fno-asynchronous-unwind-tables -fPIC -pipe -pthread -march=armv8-a -mfloat-abi=hard -mtune=cortex-a53 -mfpu=neon -mthumb -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g0 -fvisibility=hidden -Wno-psabi -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -std=gnu11 --sysroot=../../../../../../sysroot -c ../../3rdparty/chromium/third_party/zlib/deflate.c -o obj/third_party/zlib/bundled_zlib/deflate.o
FAILED: obj/third_party/zlib/bundled_zlib/deflate.o 
/home/administrator/raspi/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc -MMD -MF obj/third_party/zlib/bundled_zlib/deflate.o.d -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DOFFICIAL_BUILD -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNO_UNWIND_TABLES -DCR_SYSROOT_HASH=3fcc1d4e44127006318371002a0f421a4fde2ab4 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DZLIB_IMPLEMENTATION -DADLER32_SIMD_NEON -DINFLATE_CHUNK_SIMD_NEON -DCRC32_ARMV8_CRC32 -DARMV8_OS_LINUX -Igen -I../../3rdparty/chromium -I../../3rdparty/chromium/third_party/zlib -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -fno-unwind-tables -fno-asynchronous-unwind-tables -fPIC -pipe -pthread -march=armv8-a -mfloat-abi=hard -mtune=cortex-a53 -mfpu=neon -mthumb -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g0 -fvisibility=hidden -Wno-psabi -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -std=gnu11 --sysroot=../../../../../../sysroot -c ../../3rdparty/chromium/third_party/zlib/deflate.c -o obj/third_party/zlib/bundled_zlib/deflate.o
In file included from ../../3rdparty/chromium/third_party/zlib/deflate.c:54:0:
../../3rdparty/chromium/third_party/zlib/contrib/optimizations/insert_string.h:58:42: error: attribute(target("arch=armv8-a+crc")) is unknown
                                          const Pos str) {
                                          ^~~~~
cc1: warning: unrecognized command line option ‘-Wno-packed-not-aligned’
...

ninja: build stopped: subcommand failed.
make[3]: *** [Makefile.gn_run:344: run_ninja] Error 1
make[3]: Leaving directory '/home/administrator/raspi/qt_source/qt_5.15.2/qtwebengine/src/core'
make[2]: *** [Makefile:82: sub-gn_run-pro-make_first] Error 2
make[2]: Leaving directory '/home/administrator/raspi/qt_source/qt_5.15.2/qtwebengine/src/core'
make[1]: *** [Makefile:79: sub-core-make_first] Error 2
make[1]: Leaving directory '/home/administrator/raspi/qt_source/qt_5.15.2/qtwebengine/src'
make: *** [Makefile:49: sub-src-make_first] Error 2

I saw in many forum that could be related to a RAM problems or a lack of resources. I have tried to give the command on a 16 GB RAM machine and also tried to create a big swapfile without any result.
I saw that there are these 2 rows:

FAILED: obj/third_party/zlib/bundled_zlib/deflate.o 
error: attribute(target("arch=armv8-a+crc")) is unknown

Could you please help me to find a solution? Thanks

I will post my .config summary configuration of the qtwebengine:

Configure summary QTWEBENGINE:

Qt WebEngine Build Tools:
  Use System Ninja ....................... yes
  Use System Gn .......................... no
  Jumbo Build Merge Limit ................ 8
  Developer build ........................ no
  Sanitizer .............................. no
  QtWebEngine required system libraries:
    fontconfig ........................... yes
    dbus ................................. yes
    nss .................................. yes
    khr .................................. yes
    glibc ................................ yes
  Optional system libraries used:
    re2 .................................. no
    icu .................................. no
    libwebp, libwebpmux and libwebpdemux . no
    opus ................................. no
    ffmpeg ............................... no
    libvpx ............................... no
    snappy ............................... no
    glib ................................. yes
    zlib ................................. yes
    minizip .............................. no
    libevent ............................. no
    jsoncpp .............................. no
    protobuf ............................. no
    libxml2 and libxslt .................. yes
    lcms2 ................................ yes
    png .................................. yes
    JPEG ................................. yes
    harfbuzz ............................. no
    freetype ............................. yes
Qt WebEngineCore:
  Embedded build ......................... yes
  Full debug information ................. no
  Pepper Plugins ......................... no
  Printing and PDF ....................... no
  Proprietary Codecs ..................... yes
  Spellchecker ........................... yes
  Native Spellchecker .................... no
  WebRTC ................................. no
  PipeWire over GIO ...................... no
  Geolocation ............................ no
  WebChannel support ..................... no
  Kerberos Authentication ................ no
  Extensions ............................. no
  Node.js ................................ yes
  Support qpa-xcb ........................ no
  Building v8 snapshot supported ......... yes
  Use ALSA ............................... yes
  Use PulseAudio ......................... yes
Qt WebEngineQml:
  Support Qt WebEngine Qml ............... yes
  UI Delegates ........................... yes
  Test Support ........................... no
Qt WebEngineWidgets:
  Support Qt WebEngine Widgets ........... yes
Qt PDF:
  Support V8 ............................. no
  Support XFA ............................ no
  Support XFA-BMP ........................ no
  Support XFA-GIF ........................ no
  Support XFA-PNG ........................ no
  Support XFA-TIFF ....................... no
Qt PDF Widgets:
  Support Qt PDF Widgets ................. yes

Qt is now configured for building. Just run 'make'.
Once everything is built, you must run 'make install'.
Qt will be installed into '/home/administrator/raspi/qt5pi'.

Prior to reconfiguration, make sure you remove any leftovers from
the previous build.

artwaw

@DiegOne On Linux, Clang or GCC version 5 or later is required. Supported configurations are linux-g++, linux-clang and linux-clang-libc++

https://doc.qt.io/qt-5/qtwebengine-platform-notes.html

Skip the not supported modules. Also the ones you'd not need.

DiegOne

@artwaw

Thanks for your answer. By the way I have used a gcc 7.4.1.

This is my command to configure qtbase:

./configure -release -opengl es2 -device linux-rasp-pi3-vc4-g++ -device-option CROSS_COMPILE=~/raspi/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf- -opensource -confirm-license -nomake tests -nomake examples -make libs -verbose -no-pch -eglfs -no-xcb -no-use-gold-linker -sysroot ~/raspi/sysroot -prefix /usr/local/qt5pi -extprefix ~/raspi/qt5pi -hostprefix ~/raspi/qt5 -no-gbm -libinput -libudev

What you are suggesting to change with your comment?
Thanks

artwaw

@DiegOne

@artwaw said in Cross-compile QtWebEngine for Raspberry 3:

Skip the not supported modules. Also the ones you'd not need.

https://doc.qt.io/qt-5/configure-options.html

-skip qtwebengine and every module you don't need or is not supported.

DiegOne

@artwaw
Sorry, I can't understand if you are so general.

jsulm

@DiegOne The suggestion was to disable all modules you do not need.
To do so you use "-skip MODULE_NAME" configure parameter, like "-skip qtwebengine" to disable QtWebengine module.

DiegOne

@jsulm thanks but my goal is to cross compile qtwebengine.
In the guide I follow I can correctly build qtbase with the configure command I posted in the previous comment but when I try to build qtwebengine I get the error I described above. This is my procedure to build qtwebengine:

cd ~/raspi/qt_source/qt_5.15.2
git clone https://code.qt.io/qt/qtwebengine.git
cd qtwebengine/
git submodule init
git checkout 5.15.2
git submodule update
~/raspi/qt5/bin/qmake -- -webengine-proprietary-codecs
make
ERROR DESCRIBED ABOVE

artwaw

@DiegOne said in Cross-compile QtWebEngine for Raspberry 3:

Sorry, I can't understand if you are so general.

I was not general, you simply did not read the documentation that I linked. Then you would know what configure options are and how you can use them.

@DiegOne said in Cross-compile QtWebEngine for Raspberry 3:

my goal is to cross compile qtwebengine

Again, should you read the link I posted a few posts above - The QtWebEngine Platform Notes - you'd see that for this module the platform you want to compile for is not supported.

DiegOne

@artwaw
Thanks for your answer. I read and I re-read everything but for me is not clear since I am a beginner in qt and in cross compilation.
With this phrase:
"Supported configurations are linux-g++, linux-clang and linux-clang-libc++"
Are you telling me that it is not possible to cross-compile QtWebEngine for Raspberry 3? Why there are many guides talking about that?
In the link I also notice this phrase:
"It means that Qt WebEngine 5.15 can be built with Qt 5.12.x, Qt 5.14.x, and Qt 5.15."
Maybe should I try to cross compile version qt5.15 instead of qt 5.15.2?
Thanks in advance and I am sorry if I could not get the point.

artwaw

@DiegOne said in Cross-compile QtWebEngine for Raspberry 3:

Why there are many guides talking about that?

Ask the ones who wrote them? They obviously seem to know better.

According to the documentation it is not supported and likely not possible. If you find a way that works and can be replicated please do share as I think many people will be grateful.

DiegOne

@artwaw
If I am asking here is because I need help, not for wasting time. I already asked to the people who made the guide but they didn't reply.
do you think that also this official guide is not working?
https://wiki.qt.io/RaspberryPi2EGLFS

raven-worx

@DiegOne said in Cross-compile QtWebEngine for Raspberry 3:

error: attribute(target("arch=armv8-a+crc")) is unknown

i think your issue is that the function has the attribute target("arch=armv8-a+crc") defined.
but according to your compile call your are only compiling with -march=armv8-a. So the +crc is missing. But better would be to find the cause why it wrongly detects that it wants the crc extension.

Read this for more details about the compiler option.

Also this guides says to configure Qt with -device linux-rasp-pi3-vc4-g++ options. This enables hw acceleration via KMS, which must be supported by the Linux kernel on the Pi (i dont know thats the case, might be). Whereas -device linux-rasp-pi3-g++ would use the default Broadcom graphics stack.
Is that really desired by you?

check the file qtbase/mkspecs/devices/<DEVICE-OPTION>/qmake.conf
in that file you could also add the +crc extension flag