The Universal Serial Bus, USB, is widely used for connecting peripheral devices to a computer. Through the years devices that use USB has evolved and more and more complicated communication protocols have been developed using the USB standard. There are many different ways to set up communication between a USB device and a host computer. The USB standard does not include any security and this poses risks when designing communication over such a connection. This thesis investigates how a USB-based picture transfer protocol can be designed between a small camera running embedded Linux and a host computer. The USB functionality in Windows and Mac OS/X operating systems are investigated. Solutions to create a secure USB communication are also investigated. One of three the methods of creating a USB connection with a USB device running embedded Linux are chosen based on the investigations. A protocol is then designed and an implementation developed. The protocol designed in the thesis uses existing USB functionality in the host computer operating systems Windows and Mac OS/X. The designed protocol is evaluated for performance and security. The evaluation is made on an evaluation platform for the camera. The transfer speed of the protocol is measured to around 18 MB/s in an ideal environment. The designed protocol could be improved by using one of the security methods found in the investigations.

Actiwave AB delivers audio solutions for active speakers. One of the features is that audio can be streamed to the speakers over a local network connection. The module that provides this functionality is expensive. This thesis investigates if this can instead be achieved by taking advantage of the Spartan-6 FPGA on their platform, using part of it as a MicroBlaze soft processor on which a rendering device can be implemented. The thesis discusses design decisions such as selection and integration of operating system, UPnP framework and media decoder. A fully functional prototype application for a desktop computer was implemented, with the intention of porting it to the FPGA platform. There turned out to be too many compability issues though, so instead, a simpler renderer was implemented on the FPGA. Mp3 music files were successfully streamed to and decoded on the soft processor, but without fulfilling real-time constraints. The conclusion is that it is reasonable to implement a UPnP Media Renderer on the FPGA. Decoding in real-time can be an issue due to insufficient performance of the soft processor, but several possible solutions exist.

This work deals with application of ARM based development board as platform for remote controlling of attached peripherals. It describes practical experiences with A20- OLinuXino-Micro-4GB development board and it’s available options. Used hardware and testing peripherals are described in the next part along with programming of the software for web interface and for communication in between development board and peripherals. The second half of this document describes design process of own embedded system beginning with schematic, continuing with PCB wiring. Each step of PCB wiring process is described with required details in text, including crucial connections between processor and memory chips. The last part contains details about setting a calibration of memory chips and designing optional peripheral modules.

In recent years, more and more vendors adopt Linux to be the embedded operating system for their electronic products because of its combination of reliability, performance, good tool chains, portability, and configurability. However, Linux kernel is complex, and different electronic products may use different platforms. For this reason, it often requires that Linux be ported to different platforms. In this thesis, we describe the details of how we port Linux to a new platform which is similar to but not exactly the same as another platform and thus is not currently supported by the kernel. Moreover, we propose two robust debugging techniques to solve the problems we had encountered in this thesis. One is to make it easier to trace a module with ICE; the other is to allow us to access the internal registers of the processor through the /proc filesystem rather than write a program every time we need to access those internal registers for the purpose of, say, debugging. By using these techniques, we show that the time required to port and debug a Linux kernel can be definitely reduced.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper overviews the Research Environment for Vehicle-Embedded Analysis on Linux (REVEAL), which is an open standards framework for the creation and deployment of realtime embedded and network distributed data systems. REVEAL is an ongoing project at NASA Dryden to evaluate the feasibility and benefits of using Linux in a modern generic web-enabled data system for measurement and telemetry network research, by actually building such a system. Novel features are described, such as XML based self-configuring, self-verifying and self-documenting software, and automatic XML metadata generation. The REVEAL architecture is described, including the core server and scheduler, and the management of system and user job processing. Performance, timing, determinism, and security issues are discussed, as well as the advantages and limitations of Linux.

Off-highway vehicles are on the verge of switching from analog to digital video camera technology (VCT), which offers better video quality and new features but adds complexity to the system. This thesis project aims to implement the digital VCT to the display computer CCpilot VA intended for off-highway vehicles. In this project the differences between analog and digital VCTs were reviewed and then a demo displaying a live digital camera video feed on the embedded Linux based display computer CCpilot VA was implemented with Qt and QML. More specifically, different GStreamer pipelines were tested, as Qt uses GStreamer to play video, and camera settings were changed using the ISO 17215 standard.  The demo displayed a live digital camera video feed with high quality, low latency and high frame rate on the VA by using a GStreamer pipeline utilizing hardware decoding. The results have shown that digital video cameras perform better than analog cameras, primarily because digital cameras have better video quality. The attempts to simultaneously display a video feed and a Graphical User Interface created by Qt have been made. However, they were only successful with poor video performance. A zero-copy link between the GStreamer pipeline’s decoder and sink element must be used to obtain good video performance.

<p>Xilinx Virtex II Pro FPGA with integrated PowerPC core offers an opportunity to implementing a software and hardware codesign. The software application executes on the PowerPC processor while the FPGA implementation of hardware cores coprocess with PowerPC to achieve the goals of acceleration. Another benefit of coprocessing with the hardware acceleration core is the release of processor load. This thesis demonstrates such an FPGA based software and hardware codesign by implementing a real time video processing project on Xilinx ML310 development platform which is featured with a Xilinx Virtex II Pro FPGA. The software part in this project performs video and memory interface task which includes image capture from camera, the store of image into on-board memory, and the display of image on a screen. The hardware coprocessing core does a contrast enhancement function on the input image. To ease the software development and make this project flexible for future extension, an Embedded Operating System MontaVista Linux is installed on the ML310 platform. Thus the software video interface application is developed using Linux programming method, for example the use of Video4Linux API. The last but not the least implementation topic is the software and hardware interface, which is the Linux device driver for the hardware core. This thesis report presents all the above topics of Operating System installation, video interface software development, contrast enhancement hardware implementation, and hardware core’s Linux device driver programming. After this, a measurement result is presented to show the performance of hardware acceleration and processor load reduction, by comparing to the results from a software implementation of the same contrast enhancement function. This is followed by a discussion chapter, including the performance analysis, current design’s limitations and proposals for improvements. This report is ended with an outlook from this master thesis.</p>

Xilinx Virtex II Pro FPGA with integrated PowerPC core offers an opportunity to implementing a software and hardware codesign. The software application executes on the PowerPC processor while the FPGA implementation of hardware cores coprocess with PowerPC to achieve the goals of acceleration. Another benefit of coprocessing with the hardware acceleration core is the release of processor load. This thesis demonstrates such an FPGA based software and hardware codesign by implementing a real time video processing project on Xilinx ML310 development platform which is featured with a Xilinx Virtex II Pro FPGA. The software part in this project performs video and memory interface task which includes image capture from camera, the store of image into on-board memory, and the display of image on a screen. The hardware coprocessing core does a contrast enhancement function on the input image. To ease the software development and make this project flexible for future extension, an Embedded Operating System MontaVista Linux is installed on the ML310 platform. Thus the software video interface application is developed using Linux programming method, for example the use of Video4Linux API. The last but not the least implementation topic is the software and hardware interface, which is the Linux device driver for the hardware core. This thesis report presents all the above topics of Operating System installation, video interface software development, contrast enhancement hardware implementation, and hardware core’s Linux device driver programming. After this, a measurement result is presented to show the performance of hardware acceleration and processor load reduction, by comparing to the results from a software implementation of the same contrast enhancement function. This is followed by a discussion chapter, including the performance analysis, current design’s limitations and proposals for improvements. This report is ended with an outlook from this master thesis.

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Linux is a growing operating system in embedded systems. Today, Linux is not only in heavy servers but also in cell phones, PDAs, cameras and other devices running on battery power. While current technology is more energy efficient, more and more technologies are implemented into a single unit resulting in an overall increase of power consumption. Low power consumption is an increasingly important feature of a system today. Lower power consumption means lower costs, less environmental impact, and longer life for applications that runs on batteries. This work compiles methods to reduce power consumption of Linux systems. The work includes examining whether the available opportunities are platform-specific or of a more general nature. The evaluations of methods for efficacy, has been performed on three different platforms. Testing consists of different types of stress tests and turning the units on-and-off. The results show that many of the features for power management that are available in a Linux system are of a general nature and that the Linux kernel has good support for implementation of new power management functions. Through the power reduction tests it has been proven that reducing the frequency of the processor and bit rate of the Ethernet controller provides the highest efficiency gain at different load levels. This work also investigates whether implementation of dynamic frequency scaling on a new processor is a complex task or not. Implementations in the Linux kernel provide general code that means that only the processor-specific part needs to be implemented. The implementation was carried out without major complications. / Linux är ett växande operativsystem inom inbyggda system som finner allt fler tillämpningar i elektroniska produkter. Idag finns Linux inte enbart i tunga servrar utan även i mobiltelefoner, handdatorer, kameror och andra enheter som går på batteridrift. Samtidigt som dagens teknik är allt mer energieffektiv så implementeras allt fler tekniker i en och samma enhet vilket medför en total ökning av effektförbrukning. En låg effektförbrukning är en allt mer betydande egenskap hos ett system idag. En lägre effektförbrukning innebär lägre kostnader, mindre miljöpåverkan, och längre drifttid för applikationer som drivs på batteri. Arbetet sammanställer metoder för att reducera effektförbrukningen hos system med Linux. Arbetet innefattar även att undersöka huruvida de möjligheter som finns är plattformsspecifika eller av generell karaktär. Vid utvärdering av metoders effektpåverkan har tester utförts på tre olika plattformar. Testerna består av på- och avslag av enheter samt olika typer utav belastningstester. Resultatet visar att många utav de energisparfunktioner som finns tillgängliga i Linuxsystem är av generell karaktär och att Linuxkärnan har bra stöd för vidare implementering av energisparfunktioner. Vid försöken till effektreducering har det visat sig att minskning av hastigheten på processor och ethernet-controller ger störst vinst vid olika belastningsgrader. Arbetetet undersöker även huruvida implementationen utav dynamisk frekvensskalning på en ny processor är en komplicerad process eller inte. Resultatet visar att implementationen av funktionen för en ny processor inte är allt för komplicerad. Detta mycket på grund av att Linuxkärnans infrastruktur är uppbyggd i lager där många utav dessa lager är av generell karaktär och kan återanvändas. Detta medför att endast den hårdvaruspecifika delen behöver implementeras.