Effective Cache utilization in Multi-core Real Time Operating System

This paper will present an idea of the convergence of Visual Programming Languages (VPL) and Real Time Operating System (RTOS). The two technologies are both significant in the fields of Embedded System but developed independently of each other for years. In this paper, we will introduce the concept of VPL for RTOS (VPL-RTOS): use VPL to establish RTOS model, and then to generate code for RTOS automatically. We will also discuss the method of implementing such VPL-RTOS environments, along with how to use such kind of environments to do programming. Such VPL-RTOS can bring time saving and high software assurance. And engineers can no longer be deterred from using RTOS by complex textual codes.Copyright © 2005 by ASME

The time of delivering the embedded system solution to market is very important, because of the highly competitive market and demand of the consumer needs. In Real Time Operating System (RTOS) based embedded systems, the overall correctness of the embedded system depends on logically correct output within the specified time. Developing, testing and debugging of an RTOS based embedded system takes lots of time. The virtual platform provides the great advantage in developing, testing and debugging the RTOS based embedded system. This work describes the design and development of a reconfigurable virtual platform for real-time kernel. Eclipse IDE platform, NXP LPC-2129 target, OpenOCD have been chosen to develop this reconfigurable virtual platform for real-time kernels. For the selected target, GNU Toolchain has been configured as a plug-in in Eclipse IDE for both Windows and Linux to get own virtual platform. The μC/OS-II Board Support Package and the virtual timer for gdb debugger to support selected target has been developed and added in this virtual platform. This virtual platform facilitates the reconfiguration of the various RTOS such as μC/OS-II, DrRTOS and AVX. From the implementation of this design framework on real system, it can be concluded that the virtual platform increases the efficiency of the RTOS based applications. It gives the single solution for the developers to develop, execute, test, debug and verify the applications for various RTOS in a shorter span of time and with substantial reduction of developmental cost.

The complexity of consumer electronics devices have them employ more powerful processors as their processing load becomes higher; thus, their higher power consumption becomes a critical problem. In order to balance processing power and electrical power consumption, heterogeneous multi-core processors are becoming popular. This paper proposes an extensible RTOS (real-time operating system) architecture for such heterogeneous multi-core processors, which consist of processors with different processing power and functionalities. The architecture splits the RTOS kernel into the two components, the proxy kernel (PK) and user-level kernel (UK), and decouples dynamic resource management functions from the PK. Such architecture enables the PK to run on a less powerful core while RTOS can utilize dynamic resource management functions provided by the UK. The experiment results running micro benchmark programs show the feasibility of the proposed architecture.

Asymmetric multicore processors (AMPs) have been proposed as an energy-efficient alternative to symmetric mul-ticore processors (SMPs). However, AMPs derive their performance from core specialization, which requires co-running applications to be scheduled to run on their most appropriate core types. Despite extensive research on AMP scheduling, developing an effective scheduling algorithm remains challenging. Contention for shared resources is a key performance-limiting factor, which often renders existing contention-free scheduling algorithms ineffective. We introduce a contention-aware scheduling algorithm for ARM's big.LITTLE, a commercial AMP platform. Our algorithm comprises an offline stage and an online stage. The offline stage builds a performance interference model for an application by training it with a set of co-running applications. Guided by this model, the online stage schedules a workload by assigning its applications to their most appropriate core types in order to minimize the performance degradation caused by contention for shared resources. Our model can accurately predict the performance degradation of an application when co-running with other applications with an average prediction error of 9.60%. Compared with the default scheduler provided for ARM's big.LITTLE and the speedup-factor-driven scheduler, our contention-aware scheduler can improve overall system performance by up to 28.32% and 28.51%, respectively.

In a model-driven development context, the refinement of the architectural model of a real-time application to a Real Time Operating System (RTOS) specific model is a challenging task. Indeed, the different design choices made to guarantee the application timing properties are not always implementable on the target RTOS. In particular, when the number of distinct priority levels used at the design level exceeds the number allowed by the RTOS for the considered application, this refinement becomes not possible. In this paper, we propose a software pattern called Distinct Priority Merge Pattern (DPMP) that automatically perform the re-factoring of the architectural model when this problem occurs. First, we give an heuristic algorithm describing this pattern and we show that this method is not always effective. Then, to address the limitations of the first method, we propose a MILP formulation of the DPMP pattern that allows to check whether a solution exists and gives the optimal one. The evaluation of the second method, allows to estimate a cost in terms of processor utilization increase during the deployment of an application on a given RTOS family characterized by the number of distinct priority levels that it offers.

Most of the chicken breeders still use manual methods to regulate the temperature in the chicken coop, resulting in uncontrolled temperatures. So that during the brooding period, the chicken's physical condition is still weak and the organs of the body are still not functioning optimally so that they still need heating will be disturbed. Warming during brooding can use incandescent lamps. The heating required for brooding chickens has a range of 27° - 33° Celsius. Therefore made a system that can control the temperature with a faster response. The design of the chicken coop incubator uses RTOS to get a faster response. Real Time Operating System (RTOS) used to give priority scheduling to the chicken coop incubator system. The microcontroller will process the input data using the LM33 sensor, control the AC light dimmer module, and provide data on the LCD. Transfer function modeling using System Identification (SIT) and simulation design using Simulink Matrix Laboratory (MATLAB) software. The system in the chicken coop incubator realized using the RTOS system in the design. Comparison of the simulation results with the implementation of the time constant has a difference of 79 seconds in the open loop and 63 seconds in the close loop resulting in a time delay of the control response. The response time in the use of RTOS is faster in taking the temperature by 52.20 µs and dimmer control by 26.89 µs. However, the response time on the appearance of the data is longer by 5.34 µs.

SummaryThe increasing popularity of Internet of Things (IoT) services causes tremendous growth of the amount of produced data. These data must be effectively stored and retrieved by the IoT service providers. The solution is to access the data through application programming interfaces. The paper focuses on the problem of designing an effective data storage service for IoT, which will be available through the universal application programming interface. We propose and analyze eight variants of the distributed data storage service that differ in the database structure, that is, the hierarchical structure based on Data‐Oriented Network Architecture or the flat structure based on distributed hash table, the type of stored records, and the memory management algorithm that decides about using cache or base memory. The proposed solutions have been evaluated in the comprehensive simulation studies. The obtained results confirmed the effectiveness of the preferred solution with Dynamic Routing Records stored in the cache memory. Copyright © 2016 John Wiley & Sons, Ltd.

Fault tolerance techniques implemented at software level have been widely studied as an approach to improve reliability in processor-based systems. This paper presents a fault injection software-based methodology to emulate soft errors in processors running operational systems. The proposed method aims to accelerate the analysis of complex systems under soft errors in order to assist the development of fault tolerance mechanisms. In order to validate the proposed methodology, a simulator was implemented based on QEMU software. QEMU emulates a large number of well-known microprocessor architectures with a full system composed by memory and I/O devices. A case-study for an operational system - the Real Time Operating System (RTEMS) - running in X86 architecture was designed in the QEMU platform and faults were injected. Results show the susceptibility of the registers to faults and can guide designers in the fault tolerance techniques implemented at software level.

LPG gas leaks cause serious problems in its use, it is very vulnerable to leaks that cause LPG gas cylinders to explode and catch fire, therefore an automatic gas leak detection and monitoring system was developed. If a gas leak occurs, the sensor will immediately recognise the incident and send a notification in the form of an alarm sound and a warning notification sent to the Smartphone. This detection system is made to determine gas leaks in gas cylinder regulators using the Relatime Database method on the RTOS (Real Time Operating System) system with Fog-Cloud Computing services.

A real-time operating system (RTOS) is software which ensures that time critical events are processed as efficiently as possible. In this paper, an attempt has been taken to develop a real time operating system, named Preemptive Real Time Operating System (pRTOS), in which all of the important issues regarding to a real time application have been considered. In this pRTOS, strictly preemptive scheduling algorithm has been used. This scheduling policy makes sure that important tasks are handled first and the less important later. The Bitmap technique has been used to find out the highest priority task from the unsorted ready list. The complexity of this technique for selecting the highest priority task is O(1), which is much faster than the linear search technique having complexity of O(n). This pRTOS can support 64 priority levels ranges from 0 to 63. In addition with this, it is a highly configurable RTOS. Moreover, it can be adopted in a board range of hardware platform, say, Intel x86, MIPS, Hitachi SH, Power PC and Strong ARM processors. This RTOS has been tested on Intel x86 and from the obtained result, it has been found that our developed pRTOS can be used for various application, say, for automated industrial systems, control-systems, high-tech electronics/electrical products and home applications.

The introduction of autonomous vehicles has the potential to reduce the number of accidents and save countless lives. These benefits can only be realized if autonomous vehicles can prove to be safer than human drivers. There is a large amount of active research around developing robust algorithms for all parts of the autonomous vehicle stack including sensing, localization, mapping, perception, prediction, planning, and control. Additionally, some of these research projects have involved the use of the Robot Operating System (ROS). However, another key aspect of realizing an autonomous vehicle is a fault-tolerant design that can ensure the safe operation of the vehicle under unfavorable conditions. The goal of this thesis is to evaluate the feasibility of adding a dedicated fault tolerance module into a ROS based architecture. The fault tolerance module is used to implement a safety controller that can take over safety-critical operations of the system when a fault is detected in the main computer. A Xilinx Zynq-7000 SoC with a dual-core ARM Cortex-A9 and an FPGA programmable logic region is chosen as the platform. The platform works in the Asymmetric Multiprocessing (AMP) configuration with a Linux based operating system on one core and a real-time operating system (RTOS) on the other. Results are gathered from an implementation done on a ROS based mobile robot platform.

This paper presents the basics of an operating systems plus RTOS(Real Time Operating System) specific features. Readers are expected to have an overview of the foundations of embedded operating systems and especially RTOS. Operating systems have been evaluated by different commercial and non profit organizations. It can be seen the main lines of different operating systems.

Power management systems for embedded devices can be developed in operating system (OS) or in applications. If power management policy is applied in OS, then developers can concentrate only on application development. OS contains specific and accurate information about the various tasks being executed. Therefore, it is logical to place algorithms that place components not being used into lower power states. This can significantly reduce the energy consumption by the system. Real-time-operating-system (RTOS) has a comprehensive set of power management application programming interfaces (APIs) for both device drivers and applications within a power management component. In this paper, we provide abstracted concepts of a system power manager (PM), device power managers, and application power managers. We present relationship and interactions of these managers with each using Unified Modeling Language (UML) class diagrams, sequence diagrams and state charts. We recommend that PM must be implemented at operating system level in any embedded device. We also recommend the interfaces for interactions between PM and the devices power manager, as well as PM and application power manager. Device driver and application developers can easily use this object oriented approach to make the embedded system more power efficient, easy to maintain, and faster to develop

This paper describes the port to software of a mature text-to-speech synthesis technology that has been sold as a series of hardware products for over ten years. Originally developed as an alternative to a character cell terminal and for telephony applications, today it is also used to provide people with visually disabilities access to information. The quality of text-to-speech is extremely high in both intelligibility and naturalness and uses a digital formant synthesizer to simulate the human vocal tract. Prior to very high speed processors, the computational demands of this synthesizer placed an extreme load on a workstation. This study used a Digital Equipment AlphaModel 600 workstation to simultanoeusly convert many text streams to speech. The power of modern RISC processors allows applications to freely use speech for output. This capability has prompted the need for a text-to-speech application programming interface (API). The API that we have developed for TTS software is supported on multiple platforms and multiple operating systems. This paper presents a description of the TTS software architecture. The API is also specified. Finally, our experience in porting the TTS code base from the previous hardware platforms is described.

This paper presents a diagnosis methodology for power system disturbances, in real time, based on alarms and sequences of events (SOE). The Disturbance Diagnosis System for Real Time Operation was created to assist the operator to understand causes of disturbances, through actuated equipment protections. Its development was based on actions performed by operators during disturbances and it is, therefore, classified as a knowledge-based system. The experts' knowledge was captured and stored in a database of rules such as if … then … else. The goal is to provide better response in terms of safety and speed, which will allow operators to make more accurate decisions during the equipment restoring task due to disturbances in the power system.