path: root/doc/src/wince-customization.qdoc

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/*!
    \page windowsce-customization.html
    \ingroup qtce
    \title Windows CE - Working with Custom SDKs
    \brief How to set up Qt for use with custom Windows CE SDKs.

    When working with a custom SDK for Windows CE, Qt provides an easy way
    to add support for it to your development environment. The following is
    a tutorial that covers how to create a specification for Qt on Windows
    CE platforms.

    \tableofcontents

    \section1 Creating a Custom Build Specification

    Create a subdirectory in the \c mkspecs folder of the Qt directory.
    New specifications for Qt for Windows CE following this naming convention:

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 0

    Using this convention makes it possible for \l{qmake} to identify that
    you are building Qt for Windows CE, and will customize the compilation
    process accordingly.

    Create the files \c qmake.conf and \c qplatformdefs.h inside the new
    specification directory. Take a look at the implementation of the other
    Windows CE specifications included in the \c mkspecs directory to see
    what is required to build Qt for Windows CE successfully.


    \section1 Fine-Tuning Options

    Compared to the desktop versions, Qt for Windows CE needs two additional
    options:

    \list
    \o \bold{CE_SDK} specifies the name of the SDK.
    \o \bold{CE_ARCH} specifies information about the target architecture.
    \endlist

    Following is an example configuration for the Windows Mobile 5 for 
    Pocket PC SDK:

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 1

    \note \l{qmake} uses this information to build a valid Visual Studio
    project file. You need to ensure that they are identical to the
    configuration of the custom SDK, otherwise you might not be able to compile
    or debug your project with Visual Studio.

    Additionally, most Windows CE SDKs use extra compiler options. These
    can be specified by expanding the \c DEFINES value.

    For example, with Windows Mobile 5 for Pocket PC, the \c DEFINES variable
    is expanded in the following way:

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 2

    The mkspec may require additional configuration to be used inside of Visual
    Studio, depending on the Windows CE SDK. The above example defines
    \c _M_ARM. This definition is available internally in Visual Studio. Hence,
    the compiler will warn you about redefinition during the build step. These
    warnings can be disabled by adding a \c default_post.prf file containing
    the following lines, within the subdirectory.

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 8


    \section1 Cross-compilation Environment for a Custom SDK

    Qt for Windows CE supports a convenience script, \c{setcepaths.bat}, that
    prepares the environment in a command prompt for cross-compilation.
    However, on custom SDKs, the \c checksdk tool is provided to identify the
    environment, so Qt compiles successfully.

    \c checksdk is generated during the \c configure step and allows for the
    following options:

    \list
        \o  \c list: Returns a list of available Windows CE SDKs. (This list
            may contain one or more SDKs not supported on Qt for Windows CE,
            e.g., Pocket PC 2003.)
        \o  \c sdk: The parameter to specify an SDK. Returns a setup of
            environment variables that must be set to cross-compile Qt.
        \o  \c script: Stores your setup in a \c{.bat} file. This simplifies
            the process of switching environments when you load a command
            prompt in future.
    \endlist


    \section1 Compiling Qt for a Custom SDK

    Windows CE is highly customizable, hence it is possible that some SDKs have
    feature-stripped setups. Depending on the SDK's configuration, Qt may not
    compile in its standard configuration, as Qt for Windows CE is designed to
    be compatible with the Standard SDK setup.

    However, it is possible to exclude features of Qt and create a version that
    compiles for the desired SDK.

    Further information on stripping features can be found in the
    \l{Fine-Tuning Features in Qt}{QFeatures} documentation.


    \section1 Making Qt Applications Start on a Custom Device

    Sometimes, a Windows CE device has been created with a configuration
    different from the corresponding SDK's configuration. In this case, symbols
    that were available at linking stage will be missing from the run-time
    libraries.
    
    Unfortunately, the operating system will not provide an error message that
    mentions which symbols are absent. Instead, a message box with the following
    message will appear:

    \c{app.exe is not a valid CE application!}

    To identify the missing symbols, you need to create a temporary
    application that attempts to dynamically load the Qt for Windows CE
    libraries using \c LoadLibrary. The following code can be used for this:
    
    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 9

    Once you have compiled and deployed the application as well as the Qt
    libraries, start a remote debugger. The debugger will then print the
    ordinal number of the unresolved symbol.

    Search for parts of Qt that rely on these functions and disable them using
    the \l{Fine-Tuning Features in Qt}{QFeatures} functionality.

    In our experience, when Qt applications do not start on Windows CE, it is
    usually the result of missing symbols for the following classes or
    features:
    \list
    \o \l{Drag and Drop}
    \o \l{QClipboard}
    \o \l{QCursor}
    \endlist

    Please refer to the Microsoft documentation
    \l{http://msdn.microsoft.com/en-us/library/e7tsx612.aspx}{here} for
    information on what ordinals are and how you can create them. Information
    on accessing the corresponding symbol name to a given ordinal value can
    also be found in the Microsoft documentation.

*/

/*! 
    \page shadow builds-wince.html
    \ingroup qtce
    \title Windows CE - Using shadow builds
    \brief How to create a shadow build for Qt for Windows CE.

    \tableofcontents

    While developing for Windows CE you might want to compile a
    version of Qt for several different platforms and SDKs. In order
    to create those different builds of Qt you do not have to copy the
    whole Qt package or the Qt source. You are able to create multiple
    Qt builds from a single source tree. Such builds are called shadow
    builds.

    Basically a shadow build is created by calling configure.exe from a
    different directory.

    To make sure that the shadow build compiles correctly it is important
    that you following these guidelines:

    \list
    \o The original Qt source package must be left untouched - configure must
    never have been run in the source tree directory.

    \o The shadow build directory must be on the same level as the Qt source
        package.\br
    If the Qt package is in \c{C:\Qt\%VERSION%} the shadow build directory
    could be \c{C:\Qt\shadowbuild}. A shadow build from a directory like
    \c{C:\shadowbuild} will not compile.
    \o Avoid using "release" and "debug" in the path to the shadow build
    directory. (This is an internal limitation of the build system.)
    \o The \c{\bin} directory of the shadow build directory must be added to the
    \c PATH environment variable.
    \o Perl has been installed on your system. (\l{ActivePerl} is a popular
    distribution of Perl on Windows.)
    \endlist

    So lets assume you have installed Qt in \c{C:\Qt\%VERSION%} and you want
    to create a shadow build in \c{C:\Qt\mobile5-shadow}:

    \list
    \o First add \c{C:\Qt\mobile5-shadow\bin} to the \c PATH variable.

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 3

    \o Make sure the enviroment variables for your compiler are set.

    Visual Studio includes \c{vcvars32.bat} for that purpose - or simply use
    the "Visual Studio Command Prompt" from the Start menu.

    \o Now navigate to your shadow build directory and run configure:

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 4

    \o To build Qt, you have to update your \c{PATH, INCLUDE} and \c LIB paths
    to point to your target platforms.

    For a default installation of the Windows Mobile 5.0 Pocket PC SDK, you
    can do the following:

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 5

    We have provided a convenience script for this called \c{setcepaths}. Simply
    type:

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 6

    \o Finally, to build the shadow build type:

    \snippet doc/src/snippets/code/doc_src_wince-customization.qdoc 7

    \o That's all. You have successfully created a shadow build of Qt in
    \c{C:\Qt\mobile5-shadow}.
    \endlist
*/