![HW Acceleration in Qt
• Qt supports OpenVG and OpenGL ES >= 2.0
• Both allow HW accelerated 2D [or 3D] painting
• However, both APIs don't define the interface to
the Windowing System
30](https://image.slidesharecdn.com/dd09qtonrtos-091201053157-phpapp02/85/Qt-on-Real-Time-Operating-Systems-30-320.jpg)
Qt on Real Time Operating Systems
- 1. Qt on Real Time OSs ... or how to get your Qt app on QNX and friends 10/09/09
- 2. Contents • Some Basics – CPU, Operating System, Windowing System • Hardware Acceleration • Deeper look into... – QNX – VxWorks – INTEGRITY 2
- 3. Contents Some Basics 3
- 4. Qt for RTOS • Qt for RTOS ports are Community Supported • Not all Qt modules available • Qt APIs available unmodified (code once...) (with few exceptions that are documented in platform notes) 6
- 5. Embedded vs. Desktop • Qt Embedded can be fine-tuned for size – configure options, e.g. -no-script – feature macros, e.g. QT_NO_FILEDIALOG 4
- 6. Integration • Before we can start developing, the following must be considered: – CPU Architecture – Operating System – Windowing System 6
- 7. Contents CPU Architecture 7
- 8. Classic layer diagram QtCore Opera)ng System CPU 8
- 9. Classic layer diagram + atomics QtCore Atomic Operations Opera)ng System CPU 9
- 10. Classic layer diagram + atomics II Atomics QtCore INTEGRITY CPU 10
- 11. Summary CPU Architecture • Qt is CPU agnostic on operating systems that feature atomic operations – INTEGRITY, Windows CE • Otherwise, Qt has built-in support for... – x86_64, i386, ARM, MIPS, PowerPC, SuperH, ... • Optional: Blend and Blit optimizations (using iwMMXt, SSE, ...) 11
- 12. Contents Operating Systems 12
- 13. Classic layer diagram (again) QtCore Opera)ng System Hardware 13
- 14. OS dependencies • Qt Embedded is self-contained – Build system is bootstrapped – Requires libc, pthread, some math functions – No other external library dependencies (like STL) 14
- 15. Classic OS diagram QtCore Linux Windows Solaris Mac OS X Symbian RTOS... Hardware 15
- 16. Classic OS diagram (simplified) QtCore POSIX Win32 Hardware 16
- 17. Operating System • Qt supports – Win32 (*_win.cpp files) – POSIX (*_unix.cpp files) • Exception: Some native calls instead of POSIX for optimization or deeper integration (for example on Symbian, Mac OS X) 17
- 18. Operating System - Summary • QtCore runs well on a POSIX compliant OS/RTOS • Amount of required POSIX functionality varies (e.g. QT_NO_FILESYSTEM) • Subsystems (e.g. file system) can be replaced by native calls if necessary 18
- 19. Contents Windowing Systems 19
- 20. Classic layer diagram with GUI QtGui QtCore Windowing System Opera)ng System Hardware 20
- 21. Windowing Systems QtGui X11 S60 Windows Mac OS X ??? Linux Solaris Symbian Windows Mac OS X RTOS... Hardware 21
- 22. Introducing QWS • Qt contains it's own Windowing System: “Qt Windowing System” (QWS) • Contains a compositing window manager • Requires direct access to graphics card and input devices (mouse/touchscreen, keyboard/keypad) 22
- 23. Classic layer diagram with GUI QtGui QtCore QWS Screen Drivers Opera)ng System Input Drivers Hardware 23
- 24. QWS vs. OS QWS Drivers??? Opera)ng System Hardware 24
- 25. QWS diagram with gfx output QWS DirectFB LinuxFB Custom VNC Virtual FB Opera)ng System Hardware Network qvW 25
- 26. QVFB screenshot 26
- 27. Embedded Windowing Systems QtGui X11 QWS Linux Solaris Symbian Windows Mac OS X RTOS... Hardware 27
- 28. QWS vs. X11 • X11 – asynchronous client-server architecture, IPC – requires additional window manager process – complex due to lots of (optional) extensions • QWS – self-contained – single process mode possible 28
- 29. Contents Hardware Acceleration 29
- 30. HW Acceleration in Qt • Qt supports OpenVG and OpenGL ES >= 2.0 • Both allow HW accelerated 2D [or 3D] painting • However, both APIs don't define the interface to the Windowing System 30
- 31. Embedded Windowing Systems QtGui X11 QWS ??? ??? Opera)ng System OpenVG OpenGL (ES) Hardware 31
- 32. EGL to the rescue • EGL is the glue layer between Windowing Systems and hardware acceleration (http://www.khronos.org/egl/) 32
- 33. Embedded Windowing Systems QtGui EGL X11 QWS ??? Opera)ng System OpenVG OpenGL (ES) Hardware 33
- 34. Something still missing for QWS • EGL is still relying on an underlying windowing system • Works for X11, but not (out of the box) for QWS • OpenKODE with KDui extension required 34
- 35. Something still missing (2) • OpenKODE with KDui extension is its own windowing system • So is QWS 35
- 36. Something still missing (3) • OpenKODE with KDui extension is its own windowing system • So is QWS • #%^!@#!! 36
- 37. Introducing Lighthouse • Lighthouse is the new QWS • Lighthouse is not its own windowing system • Instead, features plug-in architecture for integrating existing windowing systems WARNING! WORK IN PROGRESS 37
- 38. Embedded Windowing Systems QtGui EGL X11 Lighthouse EGL + KD Opera)ng System OpenVG OpenGL (ES) Hardware 38
- 39. Summary Windowing System • QWS works well with non accelerated displays – HW acceleration possible, but tricky • Lighthouse works best with existing windowing systems (KDgui) with OpenGL (ES) or OpenVG • X11 works best if the infrastructure already exists for the target board, or if co-existence with other X11 applications is required 39
- 40. Summary Integration • Before writing an application, we need to... – consider the atomic operation support – consider the feature set – consider the windowing system – consider the hardware acceleration • If that's done, it's write once, deploy everywhere 40
- 41. Contents Demo 41
- 42. Contents A Deeper Look Into... QNX 42
- 43. QNX • QNX port is community supported – About 5 occurrences of conditional Q_OS_QNX code • Several successful deployments – QWS without HW acceleration • No Photon integration – Photon is a windowing system → collides with QWS • Photon's X11 server not recommended – Doesn't feature Xrender, poor rendering quality 43
- 44. QWS diagram on QNX QWS io-‐display Custom VNC Experimental! QNX Hardware Network 44
- 45. QNX - limitations • No QSystemSemaphore, QSharedMemory – SYSV style semaphores and shared memory missing from QNX • No QProcess support – Starting a process in a thread not supported • QWS has single process GUI support only • No Qt3Support 45
- 46. QNX • How to build (see Platform Notes - QNX) – -xplatform unsupported/qws/qnx-i386-g++ – -embedded i386 – -no-qt3support – -qt-gfx-qnx – -qt-mouse-qnx – -qt-kbd-qnx – -no-exceptions – ... 43
- 47. Contents A Deeper Look Into... VxWorks 46
- 48. VxWorks • VxWorks port is community supported – About 60 VxWorks specific code changes • Several successful deployments – X11 with OpenGL acceleration 47
- 49. QtGui diagram on VxWorks QtGui X11 VxWorks Hardware 48
- 50. VxWorks - limitations • No QSystemSemaphore, QSharedMemory – No SYSV style semaphores, shared memory • No QLibrary – No plugins • Only one QApplication per system – VxWorks has flat address space • No Qt3Support 49
- 51. QNX • How to build (see Platform Notes - VxWorks) – -xplatform unsupported/qws/vxworks-simpentium-g++ – -embedded vxworks – -exceptions – -no-qt3support – ... 43
- 52. Contents A Deeper Look Into... INTEGRITY 50
- 53. INTEGRITY • Only a subset of Qt supported • Port currently only available on request 51
- 54. Contents Thank you :) (Questions?) 52