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<li class="level1"><a href="#shared-memory-and-semaphores">Shared Memory and Semaphores</a></li>
<li class="level1"><a href="#inter-application-communication">Inter-Application Communication</a></li>
<li class="level1"><a href="#screen-management">Screen Management</a></li>
<li class="level1"><a href="#sound-management">Sound Management</a></li>
<li class="level1"><a href="#event-dispatching">Event Dispatching</a></li>
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<h1 class="title">Porting Qt for Embedded Linux to Another Operating System</h1>
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<p><a href="qt-embedded-linux.html">Qt for Embedded Linux</a> is reasonably platform-independent, making use of the standard C library and some POSIX functions, but only a Linux implementation is publically available. If you are looking for a non-Linux commercial implementation, it is worth contacting <a href="mailto:qt-info@nokia.com">qt-info@nokia.com</a> to see if we can help.</p>
<p>There are several issues to be aware of if you plan to do your own port to another operating system. In particular you must resolve <a href="qt-embedded-linux.html">Qt for Embedded Linux</a>'s shared memory and semaphores (used to share window regions), and you must provide something similar to Unix-domain sockets for inter-application communication. You must also provide a screen driver, and if you want to implement sound you must provide your own sound server. Finally you must modify the event dispatcher used by <a href="qt-embedded-linux.html">Qt for Embedded Linux</a>.</p>
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<a name="shared-memory-and-semaphores"></a>
<h2>Shared Memory and Semaphores</h2>
<p><a href="qt-embedded-linux.html">Qt for Embedded Linux</a> uses System V IPC (shared memory and semaphores) to share window regions between client and server. When porting, something similar must be provided; otherwise it will not be possible to run multiple applications.</p>
<p>System V semaphores are also used for synchronizing access to the framebuffer.</p>
<ul>
<li>Modify <tt>qsharedmemory_p.cpp</tt></li>
<li>Modify <tt>qlock_qws.cpp</tt></li>
<li>Modify <tt>qwslock.cpp</tt></li>
</ul>
<a name="inter-application-communication"></a>
<h2>Inter-Application Communication</h2>
<p>To communicate between applications, <a href="qt-embedded-linux.html">Qt for Embedded Linux</a> uses the Unix-domain sockets. When porting, something similar must be provided; otherwise it will not be possible to run multiple applications.</p>
<p>It should be possible to use message queues or similar mechanisms to achieve this. With the exception of QCOP messages, individual messages should be no more than a few bytes in length (QCOP messages are generated by the client applications and not Qt for Embedded Linux).</p>
<ul>
<li>Modify <tt>qwssocket_qws.cpp</tt></li>
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<a name="screen-management"></a>
<h2>Screen Management</h2>
<p>When rendering, the default behavior in <a href="qt-embedded-linux.html">Qt for Embedded Linux</a> is for each client to render its widgets into memory while the server is responsible for putting the contents of the memory onto the screen using the screen driver.</p>
<p>When porting, a new screen driver must be implemented, providing a byte pointer to a memory-mapped framebuffer and information about width, height and bit depth (the latter information can most likely be hard-coded).</p>
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<li>Reimplement <tt>qscreen_qws.cpp</tt></li>
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<a name="sound-management"></a>
<h2>Sound Management</h2>
<p>To implement sound, <a href="qt-embedded-linux.html">Qt for Embedded Linux</a> uses a Linux style device (<tt>/dev/dsp</tt>). If you want to use the <a href="qt-embedded-linux.html">Qt for Embedded Linux</a> sound server on another platform you must reimplement it.</p>
<ul>
<li>Reimplement <tt>qsoundqss_qws.cpp</tt></li>
</ul>
<a name="event-dispatching"></a>
<h2>Event Dispatching</h2>
<p><a href="qt-embedded-linux.html">Qt for Embedded Linux</a> uses an event dispatcher to pass events to and from the <a href="qt-embedded-linux.html">Qt for Embedded Linux</a> server application. Reimplement the <tt>select()</tt> function to enable <a href="qt-embedded-linux.html">Qt for Embedded Linux</a> to dispatch events on your platform.</p>
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<li>Modify <tt>qeventdispatcher_qws.cpp</tt></li>
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