Raspberry Pi 4 cross compile

Creatorczyk

Hi,

when I tried configure Qt for cross compile (RaspberryPi 4)

./configure -release -opengl es2 -device linux-rasp-pi4-v3d-g++ -device-option CROSS_COMPILE=/home/jakub/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf- -sysroot /home/jakub/raspi/sysroot -opensource -confirm-license -skip qtwebengine -skip qtwayland -skip qtlocation -skip qtscript -make libs -prefix /usr/local/qt5pi -extprefix /home/jakub/raspi/qt5pi -hostprefix /home/jakub/raspi/qt5 -no-use-gold-linker -v -no-gbm

I got error like:

Project ERROR: Cannot run target compiler '/home/jakub/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf-g++'. Output:
===================
arm-linux-gnueabihf-g++: error: unrecognized argument in option '-mtune=cortex-a72'
arm-linux-gnueabihf-g++: note: valid arguments to '-mtune=' are: arm1020e arm1020t arm1022e arm1026ej-s arm10e arm10tdmi arm1136j-s arm1136jf-s arm1156t2-s arm1156t2f-s arm1176jz-s arm1176jzf-s arm2 arm250 arm3 arm6 arm60 arm600 arm610 arm620 arm7 arm70 arm700 arm700i arm710 arm7100 arm710c arm710t arm720 arm720t arm740t arm7500 arm7500fe arm7d arm7di arm7dm arm7dmi arm7m arm7tdmi arm7tdmi-s arm8 arm810 arm9 arm920 arm920t arm922t arm926ej-s arm940t arm946e-s arm966e-s arm968e-s arm9e arm9tdmi cortex-a15 cortex-a5 cortex-a53 cortex-a7 cortex-a8 cortex-a9 cortex-m0 cortex-m0plus cortex-m1 cortex-m3 cortex-m4 cortex-r4 cortex-r4f cortex-r5 cortex-r7 ep9312 fa526 fa606te fa626 fa626te fa726te fmp626 generic-armv7-a iwmmxt iwmmxt2 marvell-pj4 mpcore mpcorenovfp native strongarm strongarm110 strongarm1100 strongarm1110 xscale
Using built-in specs.

My qmake.conf file:

# qmake configuration for the Raspberry Pi 4 (32-bit) using the Mesa V3D
# graphics stack. (not the Broadcom stack)
#
# This supports accelerated OpenGL both for X11 and DRM/KMS.  Perhaps
# Wayland too.
#
# Tested with a sysroot created from Raspbian Buster and a gcc 7.4
# toolchain from Linaro.
#
# Example configure command line, assuming installation to
# /usr/local/qt5pi on device and ~/rpi/qt5 on the host:
#
# ./configure -release -opengl es2 -device linux-rasp-pi4-v3d-g++ -device-option CROSS_COMPILE=~/rpi/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf- \
#   -sysroot ~/rpi/sysroot -opensource -confirm-license -make libs -prefix /usr/local/qt5pi -extprefix ~/rpi/qt5 -v
#
# Check the configure output carefully. EGLFS, EGLFS GBM, and EGL on X11
# should all be 'yes'. Otherwise something is wrong.
#
# If getting linker errors like "undefined reference to `_dl_stack_flags'" check the
# symlinks in the sysroot, they were probably not adjusted
# correctly. F.ex. sysroot/usr/lib/arm-linux-gnueabihf/libpthread.so must point to
# sysroot/lib/arm-linux-gnueabihf/libpthread.so.0. If it is a broken link instead, bad
# things will happen.

include(../common/linux_device_pre.conf)

QMAKE_LIBS_EGL         += -lEGL
QMAKE_LIBS_OPENGL_ES2  += -lGLESv2 -lEGL

QMAKE_CFLAGS            = -march=armv8-a -mtune=cortex-a72 -mfpu=crypto-neon-fp-armv8
QMAKE_CXXFLAGS          = $$QMAKE_CFLAGS

DISTRO_OPTS            += hard-float
DISTRO_OPTS            += deb-multi-arch

EGLFS_DEVICE_INTEGRATION = eglfs_kms

include(../common/linux_arm_device_post.conf)

load(qt_config)

What should I do??
I noticed that in qmake.conf file is a 32 bit configuration but in "./configure" commad I declared

jsulm

@Creatorczyk The compiler errors says that the compiler does not understand -mtune=cortex-a72, so remove -mtune=cortex-a72 from QMAKE_CFLAGS or change it to one understood by the compiler (it prints out what it understands).
What compiler version do you use? Maybe you should use a newer compiler.

Creatorczyk

@jsulm I think I shouldn't remove "-mtune = cortex-a72" from qmake.conf , because it's configuration dedicated for RaspberryPi 4.

Which compiler do you mean about update? On ubuntu, on Rpi4 or from tool folder?

SGaist

Hi,

Then you have to update your compiler to a version that supports that mtune value.

Creatorczyk

@SGaist Are you talking about the compiler I chose in "./configure"?

CROSS_COMPILE=/home/jakub/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf-

SGaist

Yes that one.

Creatorczyk

@SGaist @jsulm After updating the compiler, it worked. Thanks!!!!