CODEWITHSUNDEEP
linuxqtlinkercross-compilingsymlink
sj755
sj755

Reputation: 4062

Incompatible libc.so.6 Found During Cross-Compilation of Qt5 OpenGL Test for i.MX6

I'm trying to cross-compile Qt5 for the Freescale i.MX6 processor. I've already built an image using the latest Yocto package.

Before compilation of qtbase, a test for OpenGL functionality is first ran by compiling an some OpenGL code. However, during this test the compiler complains that an incompatible libc.so.6 is found.

I've discovered in another post (which I can't find at the moment), that such an error occurs because /lib/libc.so.6 is actually a symbolic link which points to the actual shared object file. However, the compiler does not use the shared object file pointed to by libc.so.6, instead trying to link to the symbolic link itself, thus the compatibility issue.

Here is the output when the configure script is ran:

OpenGL ES 2.x auto-detection... ()
/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/bin/armv7a-vfp-neon-poky-linux-gnueabi/arm-poky-linux-gnueabi-g++ -c -pipe -mfloat-abi=softfp -O2 -O2 -march=armv7-a -mfpu=neon -DLINUX=1 -DEGL_API_FB=1 -Wall -W -fPIE  -I../../../mkspecs/devices/linux-imx6-g++ -I. -I/home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint/usr/include -o opengles2.o opengles2.cpp
/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/bin/armv7a-vfp-neon-poky-linux-gnueabi/arm-poky-linux-gnueabi-g++ -Wl,-rpath-link,/home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint/usr/lib -Wl,-O1 -o opengles2 opengles2.o   -L/home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint/usr/lib -lGLESv2 -lEGL -lGAL 
/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/libexec/armv7a-vfp-neon-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/4.7.2/ld: skipping incompatible /lib/libc.so.6 when searching for /lib/libc.so.6
/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/libexec/armv7a-vfp-neon-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/4.7.2/ld: cannot find /lib/libc.so.6
/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/libexec/armv7a-vfp-neon-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/4.7.2/ld: skipping incompatible /usr/lib/libc_nonshared.a when searching for /usr/lib/libc_nonshared.a
/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/libexec/armv7a-vfp-neon-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/4.7.2/ld: cannot find /usr/lib/libc_nonshared.a
/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/libexec/armv7a-vfp-neon-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/4.7.2/ld: cannot find /lib/ld-linux.so.3
collect2: error: ld returned 1 exit status
gmake: *** [opengles2] Error 1
OpenGL ES 2.x disabled.
The OpenGL ES 2.0 functionality test failed!

Here is the script I used to supply the proper options to the configure script:

#!/bin/sh
./configure -v -opensource -confirm-license -no-pch -opengl es2 \
        -make libs -device imx6 \
        -make examples -make demos \
        -device-option CROSS_COMPILE=/home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/bin/armv7a-vfp-neon-poky-linux-gnueabi/arm-poky-linux-gnueabi- \
        -sysroot /home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint -no-gcc-sysroot \
        -prefix /opt/qt5

At the moment, I'm considering just renaming the actual shared object file to libc.so.6, but that doesn't seem like a good way to fix things.

Upvotes: 1

Views: 4160

Answers (1)

Peter DW
Peter DW

Reputation: 456

It seems that you are compiling against the wrong libc. The location of the correct libc should be: /home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint/lib/ Can you check that? Run in that folder:

file libc.so.6

Have a look if the architecture is fine. I do not have the sources in front of me, so please give feedback if things are going wrong.

Your application is compiled in a chroot environment (see man chroot). The folder /home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint acts as the new rootfolder for your application. This is configured in the -sysroot option of your configure script. This is not valid for gcc, because the -no-gcc-sysroot is on. So the linker is looking to your native /lib/ folder to find the libraries. They are not there of course.

So, can you try the following things:

1) remove the -no-gcc-sysroot option in the configure script. Configure again and try to make.

2) This can possibly fail because the compiler does not find back it's own components. Please mount the directory of the compiler into your chroot enviroment. Run the next commands:

mkdir /home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint/usr/bin -p

mount --bind /home/Desktop/poky-dylan-9.0.0/build/tmp/sysroots/x86_64-linux/usr/bin/ /home/Desktop/poky-dylan-9.0.0/build/tmp/deploy/images/mountpoint/usr/bin

Configure again and try again to make.

3) If it still is not working, the cross-compiler is not set properly. Change into the configure script argument list the CROSS_COMPILE argument:

CROSS_COMPILE=/usr/bin/armv7a-vfp-neon-poky-linux-gnueabi/arm-poky-linux-gnueabi-

I wish you good luck. Let me know if it is working or not.

Upvotes: 4

Related Questions