Automatic synthesis and verification of real-time embedded software for mobile and ubiquitous systems

Currently available application frameworks that target the automatic design of real-time embedded software are poor in integrating functional and non-functional requirements for mobile and ubiquitous systems. In this work, we present the internal architecture and design flow of a newly proposed framework called Verifiable Embedded Real-Time Application Framework (VERTAF), which integrates three techniques namely software component-based reuse, formal synthesis, and formal verification. Component reuse is based on a formal unified modeling language (UML) real-time embedded object model. Formal synthesis employs quasi-static and quasi-dynamic scheduling with multi-layer portable efficient code generation, which can output either real-time operating systems (RTOS)-specific application code or automatically generated real-time executive with application code. Formal verification integrates a model checker kernel from state graph manipulators (SGM), by adapting it for embedded software. The proposed architecture for VERTAF is component-based which allows plug-and-play for the scheduler and the verifier. The architecture is also easily extensible because reusable hardware and software design components can be added. Application examples developed using VERTAF demonstrate significantly reduced relative design effort as compared to design without VERTAF, which also shows how high-level reuse of software components combined with automatic synthesis and verification increases design productivity.     

基于UML的SoC建模设计方法研究

随着集成电路制造工艺的发展,嵌入式计算机应用向着SoC的方向发展。为了适应制造工艺对SoC设计能力的要求,提高SoC的设计效率,成为了很紧迫的必要任务。采用统一的SoC系统级建模语言SystemC、软/硬件协同设计技术、基于IP核复用等技术的SoC设计流程,在一定程度上满足了SoC设计要求。在现有SoC设计流程基础上,结合UML的模型驱动框架（MDA）设计方法,在当前的SoC设计流程的系统需求规约描述、硬件实时反应式系统建模、软件模块设计实现中采用UML针对SoC的轻量型扩展特性,可以很大程度地改进提高SoC的设计流程效率。     

Design pattern oriented development of model transformations

Model-driven engineering (MDE) is considered a well-established software development approach that uses abstraction to bridge the gap between the problem space and the software implementation. In MDE, many problems are solved using model transformation, which is a paradigm that manipulates high-level models to translate, evolve, or simulate them. However, the development of a model transformation for a specific problem is still a hard task. The main reason is the lack of a development process where transformations must be designed before implemented. Design patterns provide experiential reuse to software engineers when faced with recurring problems. Given their various contexts of application, model transformations may also benefit from design patterns. Although several studies have proposed design patterns for model transformation, there is still no accepted common language to express transformation patterns. Therefore, we propose a semi-formal way to describe model transformation design patterns that is independent from a specific transformation language and described in a practical way that is directly implementable by model engineers. This paper presents a catalog of 15 model transformation design patterns. We also demonstrate how it is possible to automatically generate excerpts of a model transformation in various languages given a design pattern. We conducted an initial survey to motivate the need for model transformation design patterns and a user study to validate the methodology we propose to solve problems as model transformations based on design patterns.     

The COMPLEX methodology for UML/MARTE Modeling and design space exploration of embedded systems

The design of embedded systems is being challenged by their growing complexity and tight performance requirements. This paper presents the COMPLEX UML/MARTE Design Space Exploration methodology, an approach based on a novel combination of Model Driven Engineering (MDE), Electronic System Level (ESL) and design exploration technologies. The proposed framework enables capturing the set of possible design solutions, that is, the design space, in an abstract, standard and graphical way by relying on UML and the standard MARTE profile. From that UML/MARTE based model, the automated generation framework proposed produces an executable, configurable and fast performance model which includes functional code of the application components. This generated model integrates an XML-based interface for communication with the tool which steers the exploration. This way, the DSE loop iterations are efficiently performed, without user intervention, avoiding slow manual editions, or regeneration of the performance model. The novel DSE suited modelling features of the methodology are shown in detail. The paper also presents the performance model generation framework, including the enhancements with regard the previous simulation and estimation technology, and the exploration technology. The paper uses an EFR vocoder system example for showing the methodology and for demonstrative results.     

基于UML和平台的嵌入式系统设计方法研究

针对嵌入式系统设计和开发的特点和需求的不断提高导致设计开发的复杂性,研究了将UML和平台结合进行嵌入式系统设计的一种方法,使用UML描述平台细节和所提供的功能;利用UML的扩展特性建立了一种UML平台profile,包含建立新的构造类、构造关系、标签值和约束;并将这种UML和平台相结合的设计方法应用在嵌入式系统实例上,选择了组成嵌入式系统实例的硬件和软件平台,针对实例平台不同的服务层次建立了面向应用建模服务的相应实例平台模型,使用了静态图和动态图表示了这种平台模型,并且描述了实例平台模型的一种应用.     

基于MicroBlaze软核处理器的Bootloader设计

文章介绍了基于MicroBlaze软核处理器的Bootloader程序的设计,详细介绍了适用该程序的FPGA嵌入式系统的硬件配置及Bootloader程序设计的硬件逻辑设计流程和软件设计流程。该程序是在FPGA硬件配置完毕之后,在内部处理器上运行的一段启动代码,用来将FLASH中的用户程序传输至外部RAM,并引导嵌入式系统从用户程序中开始运行。它解决了使用大规模复杂应用程序的嵌入式系统的引导问题,已在实际中应用,具有良好的适应性。     

基于UML的软硬件协同设计方法

嵌入式系统软硬件协同设计中关键步骤之一是软硬件划分。文中通过介绍现有嵌入式系统的协同设计方法,如:VULCAN,COSYMA和POLIS,指出了现有方法的缺点,提出了一种改进的基于UML的新方法。使用UML建立系统模型,根据UML的图例,采用二叉树的结构,计算出每个步骤的成本;采用改进的遗传算法,加快收敛的速度,提高解的质量。在算法库和成本库中对系统的软硬件进行划分,通过协同综合,达到协同仿真和验证的目的。     

一种智能手机电源管理方案的设计与实现

叙述了一种以嵌入式Linux为操作系统的智能手机电源管理方案的设计原则、设计框架和实现要点.该方案在嵌入式Linux的基础上,针对智能手机软件环境复杂、对电源持续工作要求高的特点,设计和实现了从内核支持到应用程序的完整的电源管理软件框架.该方案与嵌入式图形运行环境的结合,使得电源管理的状态更容易监测、行为更容易控制;对硬件设计的讨论则体现了软硬件协同设计的思想.     

UML嵌入式系统设计

UML是当今最流行的标准建模语言,嵌入式系统是以应用为中心、以计算机技术为基础的专用计算机系统,是软件和硬件的综合体;而嵌入式系统设计的好坏是数字商品成功荫关键。本文重点讨论UML建模中重要的概念,以及如何在嵌入式系统设计中使用UML OOD建模技术,并结合实例“微波炉小灯”演示采用UML的嵌入式系统设计过程。     

UML嵌入式系统设计

UML是当今最流行的标准建模语言,嵌入式系统是以应用为中心、以计算机技术为基础的专用计算机系统,是软件和硬件的综合体;而嵌入式系统设计的好坏是数字商品成功的关键。本文重点讨论UML建模中重要的概念,以及如何在嵌入式系统设计中使用UMLOOD建模技术,并结合实例微波炉小灯演示采用UML的嵌入式系统设计过程。     

基于MIPS的嵌入式VOD代理服务器的实现

为解决目前中小型园区网VOD应用中的网络阻塞问题,提出了一种基于MIPS的嵌入式VOD代理服务器.介绍了该代理服务器的工作原理和实施方法,以及硬件和软件的设计与实现.在某校园网中的试运行表明,该代理服务器的使用效果良好,可广泛应用于中小型园区网VOD应用系统的建设与改造.     

Applying MDE to the (semi-)automatic development of model transformations

ContextModel transformations play a key role in any software development project based on Model-Driven Engineering principles. However, despite the inherent complexity of developing model transformations, little attention has been paid to the application of MDE principles to the development of model transformations.ObjectiveIn order to: (a) address the inherent complexity of model transformation development and (b) alleviate the problem of the diversity of the languages that are available for model transformation, this paper proposes the application of MDE principles to the development of model transformations. In particular, we have adopted the idea of handling model transformations as transformation models in order to be able to model, transform and generate model transformations.MethodThe proposal follows an MDA-based approach that entails the modeling of model transformations at different abstraction levels and the connection of these models by means of model transformations. It has been empirically validated by conducting a set of case studies following a systematic research methodology.ResultsThe proposal was supported by the introduction of MeTAGeM, a methodological and technical framework for the model-driven development of model transformations that bundles a set of Domain-Specific Languages for modeling model transformations with a set of model transformations in order to bridge these languages and (semi-)automate model transformations development.ConclusionThis paper serves to show that a semi-automatic development process for model transformations is not only desirable but feasible. This process, based on MDE principles, helps to ease the task of developing model transformations and to alleviate interoperability issues between model transformation languages.     

使用UML对μC/OS-II建模与分析

使用统一建模语言（UML）对嵌入式实时操作系统C/OS-II做静态建模和动态建模,进而利用UML的可视化模型来描述和分析C/OS-II的系统结构和工作机理。通过UML静态建模,为基于C/OS-II的嵌入式系统设计,提供了一个运用面向对象技术的框架;通过UML动态建模,详细分析了嵌入式实时操作系统（ERTOS）的关键方面,包括实时内核的调度机理、优先级反转问题及其解决办法等。     

基于动态数据流图的嵌入式系统设计

该文提出一种嵌入式系统软硬件协同设计方法,它以动态数据流图为系统模型对嵌入式系统的功能和性能需求进行描述,由此提供强大的描述、分析能力及可接受的实现规模.通过一种特定的实现结构,以及数据通路的自动综合和实现代码框架的自动生成,设计工作的主体部分可以被有效分解为一系列独立设计任务,能缩短设计周期并提高设计工作的可重用性。     

Dynamic Meta Modeling with Time: Specifying the Semantics of Multimedia Sequence Diagrams

UML offers different diagram types to model behavior and dynamics of software systems. In some domains like embedded real-time systems or multimedia systems, it is necessary to include specifications of time since the correctness of these applications depends on the fulfillment of temporal requirements in addition to functional requirements. UML thus already incorporates language features to model time and temporal constraints. Such model elements must have an equivalent in the semantic domain. We have proposed Dynamic Meta Modeling (DMM) as a means for the specification of the formal operational semantics of UML models by applying graph transformation to the meta modeling of dynamic behavior. Within this paper, we extend this approach to also account for time by building on timed graph transformations. We apply these concepts to the domain of multimedia application modeling in which we adopt UML sequence diagrams. The DMM rules with time then specify an interpreter that can be used to analyze or test a model of multimedia sequence diagrams.     

Object analysis patterns for embedded systems

Some of the most challenging tasks in building a software system are capturing, refining, and analyzing requirements. How well these tasks are performed significantly impacts the quality of the developed software system. The difficulty of these tasks is greatly exacerbated for the software of embedded systems as these systems are commonly used for critical applications, have to operate reliably for long periods of time, and usually have a high degree of complexity. Current embedded systems software development practice, however, often deals with the (requirements) analysis phase in a superficial manner, instead emphasizing design and implementation. This research investigates how an approach similar to the well-known design patterns, termed object analysis patterns, can be applied in the analysis phase of embedded systems development, prior to design and coding. Specifically, our research explores how object-oriented modeling notations, such as the Unified Modeling Language (UML), can be used to represent structural and behavioral information as part of commonly occurring object analysis patterns. This work also investigates how UML-based conceptual models of embedded systems, based on the diagram templates in the object analysis patterns, can be automatically analyzed using the Spin model checker for adherence to properties specified in linear-time temporal logic (LTL) using a previously developed UML formalization framework. We have applied these patterns to several embedded systems applications obtained from the automotive industry. This paper describes one of our case studies and illustrates how our approach facilitates the construction of UML-based conceptual models of embedded systems and the analysis of these models for adherence to functional requirements.     

VERTAF: an application framework for the design and verification of embedded real-time software

The growing complexity of embedded real-time software requirements calls for the design of reusable software components, the synthesis and generation of software code, and the automatic guarantee of nonfunctional properties such as performance, time constraints, reliability, and security. Available application frameworks targeted at the automatic design of embedded real-time software are poor in integrating functional and nonfunctional requirements. To bridge this gap, we reveal the design flow and the internal architecture of a newly proposed framework called verifiable embedded real-time application framework (VERTAF), which integrates software component-based reuse, formal synthesis, and formal verification. A formal UML-based embedded real-time object model is proposed for component reuse. Formal synthesis employs quasistatic and quasidynamic scheduling with automatic generation of multilayer portable efficient code. Formal verification integrates a model checker kernel from SGM, by adapting it for embedded software. The proposed architecture for VERTAF is component-based and allows plug-and-play for the scheduler and the verifier. Using VERTAF to develop application examples significantly reduced design effort and illustrated how high-level reuse of software components combined with automatic synthesis and verification can increase design productivity.     

XUML/ACME集成建模方法与VMI构架研究

以供应商管理库存（VMI）模型的软件开发为背景,研究扩展UML（XUML）与ACME的集成建模方法及其在构架设计中的应用问题。探讨了UML结构模型和行为模型的语义扩展,以增强其表达能力,并将其用于VMI构架设计;进而基于ACME的开放语义框架,给出可实现的VMI构架模板的描述;最后对XUML和ACME两种建模方法的互补与集成的价值做了基本评价。通过在VMI软件开发中的实际应用,证明该方法是可行的,并取得良好的效果。