Case Study: Porting Qt for Embedded Linux on Embedded Processors
- 1. Porting Qt for Embedded Linux on Embedded Processors Frank Walzer – Texas Instruments
- 2. Beagle Board Peripheral I/O OMAP3530 Processor DVI-D video out 600MHz Cortex-A8 10 cm SD/MMC+ NEON+VFPv3 S-Video out 16KB/16KB L1$ USB 2.0 HS OTG 256KB L2$ I2C, I2S, SPI, 430MHz C64x+ DSP 32K/32K L1$ MMC/SD 48K L1D JTAG 32K L2 Stereo in/out PowerVR SGX GPU Alternate power 64K on-chip RAM RS-232 serial POP Memory USB Powered 256MB LPDDR RAM 2W maximum consumption 256MB NAND flash OMAP is small % of that Many adapter options Car, wall, battery, solar, …
- 3. Agenda • Motivation for using Qt at Texas Instruments • Porting Qt to TI Embedded Processors • What do we do with Qt? • Enhancing Qt through Accelerators • Future Frank Walzer Senior System Engineer Texas Instruments Germany f-walzer@ti.com
- 4. Motivation • Complexity, complexity, complexity… • Reduce amount of time to build a real system – System software – Feature complete – Easy to learn & use – OS API abstraction – Cross-platform support – Modular & flexible – Open-source • So we found Qt™ • Many other options exist but none are matching our requirements any better
- 5. Porting Qt to Embedded Processors • Many TI Embedded Processors are ARM core based – ARM supported as architecture in Qt – Qt Embedded Linux our standard choice • Follow the Qt build process – Get source download or use Git to clone Gitorious Qt tree(s) – Adaptation of mkspecs as needed – Configure, compile & test – Usually painless • Already tested devices – OMAP35xx family (Cortex-A8, DSP, PowerVR SGX) – AM35xx (Cortex-A8, PowerVR SGX) – OMAP-L137/L138 (ARM9, DSP) – DM365 and DM644x (ARM9) • Modifications to Qt sources? – Only once to work around a framebuffer issue (two lines of code) – 100% of demos and examples work unmodified – Expect changes needed for optimized hardware integration
- 6. OMAP3530 Processor OMAP35x Processor C64x+™ DSP and Display Subsystem video accelerators (3525/3530 only) LCD ARM® Video 10 bit DAC Cont- roller Enc 10 bit DAC Cortex™-A8 CPU POWERVR SGX™ Camera I/F Graphics (3515/3530 only) Image Pipe Parallel I/F L3/L4 Interconnect Peripherals Connectivity System USB 2.0 HS Timers USB OTG GP x12 Host Controller x3 Controller WDT x2 Serial Interfaces Program/Data Storage McBSP I2C UART HDQ / x2 SDRC MMC/ x5 x3 1-wire SD/ GPMC SDIO McSPI UART x4 w/IRDA x3
- 7. Our Use of Qt • Ability to support customers porting Qt – Drive Qt releases to include tested mkspecs targeting TI devices – Provide example configurations to enable advanced hardware • Creation of focused applications – Targeted end-equipment GUIs – Customer or major event support – From bare GUI prototype to full applications • Standard demonstrations – Using Qt demos and examples a lot! • Benchmarks – Either Qt demos & examples or small applications – qgears for graphics • Early system testing – Quick way to evaluate complex peripherals on new hardware
- 8. Qt Application Development • Often done cross-platform – New hardware not available in time – More efficient on PC – 99% of Qt application source code can be directly cross- compiled with no modification • Serial port exception! • Porting final applications to multiple platforms – Embedded platforms supported with multiple operating systems – Again limited hardware availability – Identical GUI maybe shown using PC only – Rapid prototyping
- 9. Development Experience • Focused on Qt Embedded Linux • Human Machine Interface demo – Done in 5 weeks – New graphical display & communications – 1 student + 0.5 engineers – Started on OMAP3 and ported to OMAP-L1 – New hardware, new to Qt • Weight Scale GUI prototype – 2 days – Developed on PC and tested on OMAP3 EVM using touch screen control • Several customer applications – Just compile and run – For benchmarking on different OS
- 10. Demo Software Stack – OMAP-L1 OS: MV pro5 Linux Qt 4.5 framework abstracts OS API Application program using C++ Object Oriented Programming Debug on other platforms possible due to Qt 4.5 cross-platform support High abstraction on application level leads to fast development Temperature Demo Qt 4.5 Embedded Linux GUI/FB Serial IO TCP/IP Timer Linux API Graphic MV Pro5 Acceleration Linux Ethernet USB/ACM Display Timer (optional) ARM / Peripherals DSP
- 11. Real Applications TSC2046 SPI OMAP3/ OMAP-L1xx
- 12. Enhancing Qt • Full support for embedded hardware beyond ARM core – PowerVR SGX core for OpenGLES, OpenVG – C6xxx DSP for effective signal processing • Ready to use with Qt classes – Initial support in Qt for OpenGLES – Still evaluating best use cases • DSP designated for multimedia applications – Possible integration of TI gstreamer-plugin with Phonon? – Already requested by customers – Very early discussion phase • Optimizing Qt for dedicated hardware requires support from silicon vendor
- 13. Future • Provide full Qt porting support – Using gitorious as platform – Update when new devices appear – Wiki: http://omap.wiki.com/Building_Qt • Evaluate Qt 4.6 SVG support – Does it integrate well with OpenVG API on OMAP3? • Drive Qt use in TI on world-wide level • Develop additional reference applications – Industrial automation market – Use Qt as GUI for process control software
- 14. Summary • Customers can benefit from Qt in a similar way – Highly efficient development – Portable and re-usable (C++) – Great GUI creation tools – Same constraints on resources as we have • We stepped into Qt at the right time – Highly successful projects for TI – Lots of customer requests – Plays well with TI plans and needs for Embedded Processing
- 15. Demonstration