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+
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/*!+
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    \page qt-embedded-crosscompiling.html+
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+
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    \title Cross-Compiling Qt for Embedded Linux Applications+
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    \ingroup qt-embedded-linux+
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+
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    Cross-compiling is the process of compiling an application on one+
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    machine, producing executable code for a different machine or+
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    device. To cross-compile a \l{Qt for Embedded Linux} application,+
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    use the following approach:+
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+
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    \tableofcontents+
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+
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    \note The cross-compiling procedure has the configuration+
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    process in common with the installation procedure; i.e., you might+
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    not necessarily have to perform all the mentioned actions+
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    depending on your current configuration.+
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+
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    \section1 Step 1: Set the Cross-Compiler's Path+
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+
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    Specify which cross-compiler to use by setting the \c PATH+
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    environment variable. For example, if the current shell is bash,+
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    ksh, zsh or sh:+
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+
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    \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 0+
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+
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    \section1 Step 2: Create a Target Specific qmake Specification+
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+
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    The qmake tool requires a platform and compiler specific \c+
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    qmake.conf file describing the various default values, to generate+
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    the appropriate Makefiles. The standard \l{Qt for Embedded Linux}+
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    distribution provides such files for several combinations of+
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    platforms and compilers. These files are located in the+
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    distribution's \c mkspecs/qws subdirectory.+
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+
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    Each platform has a default specification. \l{Qt for Embedded Linux} will+
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    use the default specification for the current platform unless told+
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    otherwise. To override this behavior, you can use the \c configure+
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    script's \c -platform option to change the specification for the host+
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    platform (where compilation will take place).+
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+
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    The \c configure script's \c -xplatform option is used to provide a+
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    specification for the target architecture (where the library will be+
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    deployed).+
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+
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    For example, to cross-compile an application to run on a device with+
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    an ARM architecture, using the GCC toolchain, run the configure+
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    script at the command line in the following way:+
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+
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    \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 1+
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+
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    If neither of the provided specifications fits your target device,+
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    you can create your own.  To create a custom \c qmake.conf file,+
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    just copy and customize an already existing file. For example:+
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+
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    \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 2+
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+
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    \note When defining a mkspec for a Linux target, the directory must+
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    be prefixed with "linux-". We recommend that you copy the entire+
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    directory.+
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+
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    Note also that when providing you own qmake specifcation, you must+
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    use the \c configure script's \c -xplatform option to make+
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    \l{Qt for Embedded Linux} aware of the custom \c qmake.conf file.+
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+
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    \section1 Step 3: Provide Architecture Specific Files+
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+
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    Starting with Qt 4, all of Qt's implicitly shared classes can+
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    safely be copied across threads like any other value classes,+
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    i.e., they are fully reentrant. This is accomplished by+
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    implementing reference counting operations using atomic hardware+
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    instructions on all the different platforms supported by Qt.+
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+
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    To support a new architecture, it is important to ensure that+
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    these platform-specific atomic operations are implemented in a+
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    corresponding header file (\c qatomic_ARCH.h), and that this file+
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    is located in Qt's \c src/corelib/arch directory. For example, the+
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    Intel 80386 implementation is located in \c+
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    src/corelib/arch/qatomic_i386.h.+
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+
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    See the \l {Implementing Atomic Operations} documentation for+
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    details.+
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+
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    \section1 Step 4: Provide Hardware Drivers+
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+
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    Without the proper mouse and keyboard drivers, you will not be+
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    able to give any input to your application when it is installed on+
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    the target device. You must also ensure that the appropriate+
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    screen driver is present to make the server process able to put+
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    the application's widgets on screen.+
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+
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    \l{Qt for Embedded Linux} provides several ready-made mouse, keyboard and+
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    screen drivers, see the \l{Qt for Embedded Linux Pointer Handling}{pointer+
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    handling}, \l{Qt for Embedded Linux Character Input}{character input} and+
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    \l{Qt for Embedded Linux Display Management}{display management}+
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    documentation for details.+
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+
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    In addition, custom drivers can be added by deriving from the+
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    QWSMouseHandler, QWSKeyboardHandler and QScreen classes+
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    respectively, and by creating corresponding plugins to make use of+
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    Qt's plugin mechanism (dynamically loading the drivers into the+
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    server application at runtime). Note that the plugins must be+
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    located in a location where Qt will look for plugins, e.g., the+
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    standard \c plugin directory.+
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+
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    See the \l {How to Create Qt Plugins} documentation and the \l+
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    {tools/plugandpaint}{Plug & Paint} example for details.+
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+
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    \section1 Step 5: Build the Target Specific Executable+
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+
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    Before building the executable, you must specify the target+
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    architecture as well as the target specific hardware drivers by+
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    running the \c configure script:+
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+
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    \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 3+
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+
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    It is also important to make sure that all the third party+
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    libraries that the application and the Qt libraries require, are+
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    present in the tool chain. In particular, if the zlib and jpeg+
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    libraries are not available, they must be included by running the+
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    \c configure script with the \c -L and \c -I options. For example:+
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+
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    \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 4+
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+
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    The JPEG source can be downloaded from \l http://www.ijg.org/. The+
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    \l{Qt for Embedded Linux} distribution includes a version of the zlib source+
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    that can be compiled into the Qt for Embedded Linux library. If integrators+
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    wish to use a later version of the zlib library, it can be+
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    downloaded from the \l http://www.gzip.org/zlib/ website.+
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+
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    Then build the executable:+
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+
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    \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 5+
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+
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    That's all. Your target specific executable is ready for deployment.+
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+
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    \table 100%+
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    \row+
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    \o \bold {See also:}+
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+
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    \l{Qt for Embedded Linux Architecture} and \l{Deploying Qt for Embedded Linux+
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    Applications}.+
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    \endtable+
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*/+
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