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diff --git a/doc/src/platforms/emb-crosscompiling.qdoc b/doc/src/platforms/emb-crosscompiling.qdoc new file mode 100644 index 0000000..2e0ba4b --- /dev/null +++ b/doc/src/platforms/emb-crosscompiling.qdoc @@ -0,0 +1,191 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at http://qt.nokia.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \page qt-embedded-crosscompiling.html + + \title Cross-Compiling Qt for Embedded Linux Applications + \ingroup qt-embedded-linux + + Cross-compiling is the process of compiling an application on one + machine, producing executable code for a different machine or + device. To cross-compile a \l{Qt for Embedded Linux} application, + use the following approach: + + \tableofcontents + + \note The cross-compiling procedure has the configuration + process in common with the installation procedure; i.e., you might + not necessarily have to perform all the mentioned actions + depending on your current configuration. + + \section1 Step 1: Set the Cross-Compiler's Path + + Specify which cross-compiler to use by setting the \c PATH + environment variable. For example, if the current shell is bash, + ksh, zsh or sh: + + \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 0 + + \section1 Step 2: Create a Target Specific qmake Specification + + The qmake tool requires a platform and compiler specific \c + qmake.conf file describing the various default values, to generate + the appropriate Makefiles. The standard \l{Qt for Embedded Linux} + distribution provides such files for several combinations of + platforms and compilers. These files are located in the + distribution's \c mkspecs/qws subdirectory. + + Each platform has a default specification. \l{Qt for Embedded Linux} will + use the default specification for the current platform unless told + otherwise. To override this behavior, you can use the \c configure + script's \c -platform option to change the specification for the host + platform (where compilation will take place). + + The \c configure script's \c -xplatform option is used to provide a + specification for the target architecture (where the library will be + deployed). + + For example, to cross-compile an application to run on a device with + an ARM architecture, using the GCC toolchain, run the configure + script at the command line in the following way: + + \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 1 + + If neither of the provided specifications fits your target device, + you can create your own. To create a custom \c qmake.conf file, + just copy and customize an already existing file. For example: + + \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 2 + + \note When defining a mkspec for a Linux target, the directory must + be prefixed with "linux-". We recommend that you copy the entire + directory. + + Note also that when providing you own qmake specifcation, you must + use the \c configure script's \c -xplatform option to make + \l{Qt for Embedded Linux} aware of the custom \c qmake.conf file. + + \section1 Step 3: Provide Architecture Specific Files + + Starting with Qt 4, all of Qt's implicitly shared classes can + safely be copied across threads like any other value classes, + i.e., they are fully reentrant. This is accomplished by + implementing reference counting operations using atomic hardware + instructions on all the different platforms supported by Qt. + + To support a new architecture, it is important to ensure that + these platform-specific atomic operations are implemented in a + corresponding header file (\c qatomic_ARCH.h), and that this file + is located in Qt's \c src/corelib/arch directory. For example, the + Intel 80386 implementation is located in \c + src/corelib/arch/qatomic_i386.h. + + See the \l {Implementing Atomic Operations} documentation for + details. + + \section1 Step 4: Provide Hardware Drivers + + Without the proper mouse and keyboard drivers, you will not be + able to give any input to your application when it is installed on + the target device. You must also ensure that the appropriate + screen driver is present to make the server process able to put + the application's widgets on screen. + + \l{Qt for Embedded Linux} provides several ready-made mouse, keyboard and + screen drivers, see the \l{Qt for Embedded Linux Pointer Handling}{pointer + handling}, \l{Qt for Embedded Linux Character Input}{character input} and + \l{Qt for Embedded Linux Display Management}{display management} + documentation for details. + + In addition, custom drivers can be added by deriving from the + QWSMouseHandler, QWSKeyboardHandler and QScreen classes + respectively, and by creating corresponding plugins to make use of + Qt's plugin mechanism (dynamically loading the drivers into the + server application at runtime). Note that the plugins must be + located in a location where Qt will look for plugins, e.g., the + standard \c plugin directory. + + See the \l {How to Create Qt Plugins} documentation and the \l + {tools/plugandpaint}{Plug & Paint} example for details. + + \section1 Step 5: Build the Target Specific Executable + + Before building the executable, you must specify the target + architecture as well as the target specific hardware drivers by + running the \c configure script: + + \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 3 + + It is also important to make sure that all the third party + libraries that the application and the Qt libraries require, are + present in the tool chain. In particular, if the zlib and jpeg + libraries are not available, they must be included by running the + \c configure script with the \c -L and \c -I options. For example: + + \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 4 + + The JPEG source can be downloaded from \l http://www.ijg.org/. The + \l{Qt for Embedded Linux} distribution includes a version of the zlib source + that can be compiled into the Qt for Embedded Linux library. If integrators + wish to use a later version of the zlib library, it can be + downloaded from the \l http://www.gzip.org/zlib/ website. + + Then build the executable: + + \snippet doc/src/snippets/code/doc_src_emb-crosscompiling.qdoc 5 + + That's all. Your target specific executable is ready for deployment. + + \table 100% + \row + \o \bold {See also:} + + \l{Qt for Embedded Linux Architecture} and \l{Deploying Qt for Embedded Linux + Applications}. + + \row + \o \bold{Third party resources:} + + \l{http://silmor.de/29}{Cross compiling Qt/Win Apps on Linux} covers the + process of cross-compiling Windows applications on Linux. + \endtable +*/ |