Third Party Programmability for Embedded Systems

目前，通用的嵌入式处理器的数量和多样性都在快速增长。 在越来越多的情况下，设备可由其用户编程。 可编程性在复杂性上有所不同，从简单的记忆功能（如手机记住一系列数字）到完全的第三方可编程性（TPP），例如，手机可以从互联网下载新软件并提供显著的新功能。 此功能允许设备利用通用计算机（如个人台式计算机或Internet服务器）的一些优点。 为了充分利用这些优势，嵌入式处理器软件平台必须具备通用计算机的一系列特性：灵活性、可移植性、可扩展性、可预测性和可交付性。 其中，向设备传送新程序是一个特别的挑战。在连接到互联网的通用计算机上安装新代码已经是一个巨大的挑战，但TPP嵌入式处理器的支持是一个更加多样化和悬而未决的问题。 通常情况下，智能设备没有联网，只有间歇性的互联网连接，或者主要通过本地对等链路在由其他智能设备组成的网络中运行。 这使得代码交付成为一个特殊的挑战，并推动了对新架构的需求。在这个项目中，我们将基于复杂连接需求的假设，为TPP智能设备推导出一系列代码交付架构。 在一般情况下，问题包括代码大小小（例如，程序可能限于一个或两个字节大小），与操作要求的交互（如现场或厨房中操作人员的天真），具有高能执行器的TPP设备的安全要求，网络通信的安全问题或恶作剧特别具有威胁性时（如汽车编程），与网络连接的相互作用（如在访问和不访问互联网的情况下运行的能力）。 我们将分析体系结构、语言和分析技术来处理这些问题。我们研究需求的早期基础将是家庭智能电器领域。 多种交付选择是这一领域目前研究的主题。 我们将开始开发一个系统，利用食品包装上的条形码对微波炉进行编程，并将我们的经验推广到其他人。 这一领域的现有系统假设太少（如可以用3-10个数字表示的食谱）或太多（如必须从互联网访问食谱的附加PC）。 一个理想的系统将允许小程序被交付的包，可以作为脚本或调用网络连接，如果它存在下载代码更实质性的功能。我们的研究还侧重于使用先进的分析技术，如正式验证的可预测性。 我们的研究将确定嵌入式应用程序的通用编程语言的适当子集，并开发使用特定领域和自动化抽象将验证技术直接应用于源代码的工具。

There are a rapidly-growing number and diversity of embedded processors in general use today. In a growing number of cases the device is programmable by its user. Programmablility varies in complexity fromsimple memory functions, like a cell phone that remembers a list of numbers, to full third-party programmability (TPP), where, for example, a cell phone can download new software from the Internetand offer significantly new functionality. This feature allows the device to exploit some of the advantages of general-purpuse computers like personal desktop computers or Internet servers. The device serves as a platform for a diversity of applications, even applications that were not yet conceived at the time the device was built.In order to exploit these advantages, embedded processor software platforms must offer a range of features well-known from general purpose computers: flexibility, portability, extensibility, predictability, and deliverability. Of these, a particularly unique challenge arises in the delivery of new programs to the device.Installing new code on general-purpose computers attached to the Internet is already a significant challenge, but the support of TPP embedded processors is an even more diverse and unsettled issue. It is often the case that smart devices are not networked, have only intermittent Internet connectivity, or operate primarily in networks consisting of other smart devices through local peer-to-peer links. This makes code delivery a particular challenge and impels the need for new architectures.In this project we will derive a range of code delivery architectures for TPP smart devices based on the assumption of complex connectivity requirements. In the general case issues include small code size (forinstance programs may be limited to one or two kilobyte sizes), interaction with operational requirements (like naivety of a human operator in the field or kitchen), safety requirements for TPP devices with high-energy actuators, security issues for network communication or when mischief is particularly threatening (like programming for automobiles), interplay with network connectivity (like ability tofunction both with and without access to the Internet). We will analyze architecture, language, and analysis techniques available to deal with the issues.An early basis for our study of requirements will be the area of smart appliances for homes. A diversity of delivery options are the subject of current research in this area. We will begin by developing a system for programming microwave ovens using bar codes on food packages and generalize our experience with this system to others. Existing systems in this area assume too little (like recipes that can be expressed with 3-10 numbers) or too much (like an attached PC that must access recipes from the Internet). An ideal system will allow small programs to be delivered on packages that can function as scripts or invoke network connectivity if it exists to download code for more substantial functionality.Our research also focuses on predictability using advanced analysis techniques such as formal verification. Our research will identify the appropriate subsets of general-purpose programming languages for embeddedapplications and develop tools for applying verification techniques directly to the source code using domain-specific and automated abstractions.