I am using open source C++ library DCMTK from http://dicom.offis.de/dcmtk.php.en.
I have successfully compiled this library on Windows using VC++ IDE, MacOS Xcode, Mac iOS simulator.
But I am not able to compile this library on iOS device as it is ARM based architecture.
DCMTK library compiled very well on Intel architecture.
Now my problem statement is :-
I need to compile this DCMTK C++ library on ARM architecture by cross compilation.
I am using Ubuntu 64 bit machine for cross compilation.
I have installed binaries from GNU ARM tool chain from http://www.gnuarm.com/
I am using GCC toolchain 4.0 binutils-2.16.1, gcc-4.0.2-c-c++, newlib-1.14.0, insight-6.4, TAR BZ2 [65.5MB] binaries for Ubuntu 64 bit machine for ARM cross compilation.
After Installing these binaries on Ubuntu I have set PATH environment variable to
PATH=$PATH/gnu_arm/bin
For configuring the DCMTK C++ library I have run the following command on shell
CC=arm-elf-gcc CXX=arm-elf-g++ AR=arm-elf-ar RANLIB=arm-elf-ranlib ARFLAGS=cruv ./configure –prefix=$home_dicom –target=arm-elf –host=arm-elf –enable-std-includes –disable-threads
It creates a make file properly. Now I am trying to compile the code by using make command, but facing so many compilation errors like :-
1) I tried to compile my first dependent C++ library that is ofstd.
I got error for DIR*, struct dirent, opendir(), closedir() calls.
It includes for these calls, but I did not found any definitions for the above calls in this header file.
2) When I compile another library oflog I got the following errors like
error: nthos was not declared in this scope
error: ntohl was not declared in this scope
error: htons was not declared in this scope
error: htonl was not declared in this scope.
These calls are networking calls and are not defined in any of the header file from GNU ARM tool.
I tried to download the sources of ARM binaries and extracted the tar files and try to copy missing header files to installed GNU ARM on Ubuntu.
For some files it compiles after doing changes to copied header files, and for some again it gives compilation errors.. There is a loop of compilation errors for every file present under DCMTK library as some of the standard header files are missing.
Please suggest if there is any other tool chain available for ARM cross compilation on Ubuntu 64 bit machine.
Or any other good solution apart from this.
Thanks!!!
Amit
There are many areas for problems when it comes to cross compiling. There are three main flags for cross compiling. -host , -target, and -build. The -host flash is the machine in which the resulting binaries will run on. The -build flash is the system in which you will be compiling on. The -target flag is for building libraries that will be used in cross compiling. So if you were to build your own gcc tool chain. So in your case you won't set the target flag as we're not building a tool chain. the -host flag will be arm-elf. And the -build flag will be amd64.
Usually a cross compilation fails if there are inconsistencies between the regular c compiler and the cross compiler. I have compiled several libraries for the avr32 with a toolchain generated by buildroot, but in some cases (socat project for example) it hasn't been possible.
Your host, your target and the CXX flags look ok. I think it is not necessary to put the AR flag (that is the idea with the host and target option).
In other hand, this is an example for the expat libraries for the avr32:
./configure --host=avr32-linux --prefix=/home/juan/builds/build_expat/ CC=avr32-linux-gcc
make; make install
I can recommend you that tries to cross compile from an ia32 architecture. I had several problems with that ubuntu in the past.
Related
In our project team we applications for micro-controller targets with arm-none-eabi-gcc. For running our testrunner we compile using the native cc compiler.
In our project team most use a Linux os, but some us a windows os (for reasons). The issue we run into is that we use the C11 keyword _Static_assert. When compiling on Linux it works, but when compiling under windows we get the following error: error LNK2019: unresolved external symbol _Static_assert referenced in function {}
This is due to the reason that the default MSVC compiler implements ANSI C89 which doesn't support the _Static_assert symbol. MSVC - C standards support
It also specifies that adding the /std:c11 or /std:c17 compiler options enable the support for _Static_assert.
We already have enabled --enable_platform_specific_config for other reasons.
Simply adding the build:windows --copt="/std:c11" to the .bazelrc solves the issue but also breaks the normal application build because arm-none-eabi-gcc compiler doesn't support the /std:c11 compiler flag.
Question: How can i add the /std:c11 compiler flag so that it only propagates to the native msvc compiler and not to the rest of my build targets?
When using MSVC for host builds (when building a tool that emits source code which is then #include'd, for example protocol buffer compiler) add build:windows --host_copt="/std:c11". When using MSVC for test builds, add test:windows --host_copt="/std:c11". Don't put it in build:windows --copt because that will apply even when running builds to the target.
I'm attempting to use OpenCV for Windows as supplied by opencv.org in a project I'm building with JetBrains' CLion IDE. I've installed the opencv library and configured CLion (set(OpenCV_DIR) to reference the build directory under it, but CMake issues the warning:
Found OpenCV Windows Pack but it has no binaries compatible with your configuration.
You should manually point CMake variable OpenCV_DIR to your build of OpenCV library.
I've tried some of the older distributions from opencv.org with the same results. It appears CMake is locating the OpenCV libraries, but doesn't want to use them. Why, and how do I get the OpenCV libraries to work under CLion?
The short answer is, you will probably need to build OpenCV from source in order to use it with CLion. But given the number and range of partially answered and unanswered questions here* and elsewhere on using JetBrains' CLion IDE with the OpenCV library, I think an overview is needed (my notes are from CLion 2016.3 and OpenCV 3.1, YMMV):
Though not produced by JetBrains, CMake is very central to CLion's operation. Understanding CMake therefore helps greatly in diagnosing CLion build problems. In particular CMake maintains a disk "cache" of settings which you may need to clear to incorporate changes to your environment (Tools->CMake->Reset Cache and Reload Project).
To make use of OpenCV in your build you must specify it in your project's CMakeLists.txt file. You request that CMake locate your OpenCV location and link it to your TARGET. An example of a sequence of commands from CMakeLists.txt for an executable named mushroom follows:
add_executable(mushroom ${SOURCE_FILES})
FIND_PACKAGE(OpenCV REQUIRED)
TARGET_LINK_LIBRARIES(mushroom ${OpenCV_LIBS})
(For more on FIND_PACKAGE, see CMake:How To Find Libraries.)
FIND_PACKAGE for package XXX works either by way of FindXXX.cmake files located at CMake's Modules directory, or by consulting environment variable XXXX_DIR. On my system, no FindOpenCV.cmake file was present, so I relied on the OpenCV_DIR environment variable instead. This must be set, not to the root of your OpenCV installation, but to the build folder beneath it. I used an entry in CMakeLists.txt to set this variable, e.g.:
set(OpenCV_DIR C:/Users/myacct/AppData/Local/opencv-3.0.0/build)
To link with OpenCV, CMake uses either FindOpenCV.cmake or OpenCV_DIR (see previous point above) to locate a file named OpenCVConfig.cmake. This file is generated by and ships with a particular build of OpenCV in order to document what components are present and where they are located.
Problems may occur when variable names used by OpenCVConfig.cmake conflict with those CLion has stored in its environment. In particular, if your OpenCV was built by Microsoft Visual C (MSVC), as is the Windows distribution from opencv.org, it won't work with CLion.
Because CLion's build toolchain (ControlAltS-toolchain) uses either MinGW or Cygwin, OpenCVConfig.cmake will search for OpenCV binaries under a subdirectory named mingw or cygwin and will find none because the binaries were built with MSVC (it will look in a directory like vc11 or vc12 instead). This probably means you will need to build OpenCV from source in order to use it with CLion.
Would reconfiguring OpenCVConfig.cmake to point to the MSVC binaries make this work? you may ask. Unfortunately the answer is still no, because libraries built with one compiler typically cannot be linked with another one.
OpenCVConfig.cmake or FindOpenCV.cmake likely contain diagnostic messages, but when CLion executes CMake for you, message(STATUS) calls are not displayed. To make them display, change them to message(WARNING) or message(FATAL_ERROR). But CLion 2016.3 EAP relieves this problem; see https://stackoverflow.com/a/39398373/5025060.
CLion does not indicate which .cmake script issued which diagnostics; don't assume they all come from the same script.
Hopefully this provides some general guidance on resolving CLion / CMake / OpenCV compatibility problems. Note that this does not cover compiler or linker issues; these will not appear until CMake completes its initial makefile build. Compiler or linker issues occur at a later stage and are controlled by include*(), link*() and other commands in CMakeLists.txt.
*Some related SO questions:
OpenCV Windows setup with CLion
OpenCV CLion (Cmake) linking issue - cmake reports a strange error
use OpenCV with Clion IDE on Windows
Compiling OpenCV on Windows with MinGW
Could not find module FindOpenCV.cmake ( Error in configuration process)
CMake: Of what use is find_package() if you need to specify CMAKE_MODULE_PATH anyway?
I have some existing source code that is written in C that I want to build and include in my iOS project. The entire source package is very large and is built using existing Makefiles and GCC. It is producing static libraries (.a files) that I would love to move over to my iOS project. However, the static libraries the Makefile produces is for x86 processors, which obviously won't work on iOS.
Is there a way I can switch GCC to build for ARMv7/ARM64 instead, without making changes to the existing source (in most cases)? I know there is the -march switch for GCC or you can download ARM specific GCC compilers, so I know the general concept of building for a different architecture than the build machine.
To build for ARM on Mac OS, will I have to download a different GCC compiler or is that capability built into the default GCC?
I'm sorry for the lack of understanding of basic concepts here; I'm primarily a Java and Objective-C developer, so building source for different architectures is a mostly foreign concept to me.
Whilst GCC supports a good many CPU architecture and platforms, it is usually built for a single one. To compile for ARM you generally need an ARM-cross-compiling GCC targeted appropriately.
The default system compiler for MacOSX and iOS for all architectures is clang and has been for some time (the last version of GCC apple shipped in dev tools is creaking and obsolete, and definitely won't support ARMv8).
The usual way of getting clang is to install Xcode (free from the App Store). There's a option in the installer (and in the UI of Xcode) to install the command-line tool package. This installs sym-links in /usr/bin to the compiler, and installs a bunch of other stuff you might expect such as make.
clang is (mostly) command-line compatible with gcc, and furthermore, you'll find that if you run gcc from the command-line on a Mac with dev-tools installed, you in fact get clang.
$ gcc --version
Configured with: -- prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/c++/4.2.1
Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix
clang comes with ARMv7, ARMv8, i686, x86_64 on MacOSX, and can be configured to compile for any of these from the command line (See documentation)
Given the above, there's a fair chance your code will compile with minimal changes to compiler-flags using the existing makefile. You might want to read the documentation for lipo - which allows you to produce multi-architecture binaries.
I am trying to build an OS image for TI OMAP4 Pandaboard. The downloaded BSP can be built but very limited without gcc g++ compiler. I think it much difficult to add the tool chain in QNX Momentics IDE, because there are so many files to be added. Can I manually modify the buildfile to do it? If possible, please give me an example. Thanks in advance.
No, it is not possible to run g++ on your TI OMAP4 Pandaboard (unless you build g++ from sources for the ARM platform using the existing QNX toolchain running on an X86 platform).
Why not possible: QNX releases their build tools only for X86-based hosts. The currently supported host OS-es include some variants of Windows, Linux and QNX but the precondition is that the host hardware is X86-based.
Likely you do not actually want to build your library on the target hardware; it should not matter where you actually do the build (except in very special cases where you build some source code based on user input, etc.)
What you need to do is build your library on your development host using the ARM toolchain (QCC if you want to use the high-level tools; ntoarmv7-g++ if you want to use the familiar g++ interface). Once you have your binary you can include it in the .ifs file. You just need to include a line in the .build file, similar to the following example:
/path/on/targetfs/yourbinary=/path/on/buildmachine/yourbinary
If your build environment is configured so that mkifs finds your binary then you can omit the "path/on/buildmachine" part.
If you are fine with having the binary on your target under /proc/boot then you can omit the "/path/on/targetfs/ part as well.
For ease of development it would usually be more convenient for you to store your binary on the SD card with a FAT filesystem. Then you can just copy your binary to the SD without having to rebuild the .ifs file.
Finally, once you get experienced you will want to export a part of your host-machine's filesystem via CIFS or NFS and mount it directly from your target. This will save all the trouble of having to copy files (and, possibly, reboot the target) in each build cycle. But this is far off from your original question.
I think you are trying to get the QNX C/C++ compiler to run on your target board. Correct?
If so, rather than installing the Runtime Kit, you install the QNX Software Development Platform and you should be good to go.
You can also use the System Builder to customize your QNX OS, but this is going to be harder than just using the QNX SDP.
One other note: QNX uses qcc for C and QCC for C++ instead of gcc. They both use gcc under the hood, but to compile on QNX, use qcc instead of gcc.
Disclaimer: I'm fairly deep into my particular compiling issue but quite new to the world of compiling.
Background:
I'm working on a Windows 7, 64 bit machine. I'm attempting to compile a rather large fortran program using mingw-w64. The compile process is controlled by SCONS (similar or derived from gnu Make). I have successfully compiled this program via scons using g95 and mingw gfortran. I have attempted use tdm-gcc and 'ruben' builds of mingw-w64 with identical, unsatisfactory results. I am passing the -static argument to the compiler (gfortran.exe). I have tried using both the gfortran and x86_64-w64-mingw32-gfortran compile commands with identical results.
Problem:
When attempting to compile a 64bit version of my program, despite passing the -static argument to the gfortran compiler, when I attempt to run the built executable, it errors out claiming that it can't find various dll's (libgfortran, libgcc, libquadmath, generically speaking). If I copy those libraries to the working directory, the built program runs without error and performs as expected.
Anecdotal Summary:
mingw-w64 gfortran appears to be ignoring the -static compile flag
If there is any additional information I can provide to help in solving this, please let me know.
Thanks,
JTJ