lmproving Microcontroller and Computer Architecture Education through Software Simulation

In this thesis, we aim to improve the outcomes of students learning Computer Architecture and Embedded Systems topics within Software and Computer Engineering programs. We develop a simulation of processors that attempts to improve the visibility of hardware within the simulation environment and replace existing solutions in use within the classroom. We designate a series of requirements of a successful simulation suite based on current state-of-the-art simulations within literature. Provided these requirements, we build a quantitative rating of the same set of simulations. Additionally, we rate our previously implemented tool, hc12sim, with current solutions. Using the gaps in implementations from our state-of-the-art survey, we develop two solutions. First, we developed a web-based solution using the Scala.js compiler for Scala with an event-driven simulation engine through Akka. This Scala model implements a VHDL-like DSL for instruction control definition. Next we propose tools for developing cross-platform native applications through a project-based build system within CMake and a continuous integration pipeline using Vagrant, Oracle VirtualBox and Jenkins. Lastly, we propose a configuration-driven processor simulation built from the original hc12sim project that utilizes a Lua-based scripting interface for processor configuration. While we considered other high-level languages, Lua best fit our requirements allowing students to use a modern high-level programming language for processor configuration. Instruction controls are defined through Lua functions using high-level constructs that implicitly trigger low-level simulation events. Lastly, we conclude with suggestions for building a new solution that would better meet requirements set forth in our research question building from successful aspects from this work

Extempore: The design, implementation and application of a cyber-physical programming language

There is a long history of experimental and exploratory programming supported by systems that expose interaction through a programming language interface. These live programming systems enable software developers to create, extend, and modify the behaviour of executing software by changing source code without perceptual breaks for recompilation. These live programming systems have taken many forms, but have generally been limited in their ability to express low-level programming concepts and the generation of efficient native machine code. These shortcomings have limited the effectiveness of live programming in domains that require highly efficient numerical processing and explicit memory management. The most general questions addressed by this thesis are what a systems language designed for live programming might look like and how such a language might influence the development of live programming in performance sensitive domains requiring real-time support, direct hardware control, or high performance computing. This thesis answers these questions by exploring the design, implementation and application of Extempore, a new systems programming language, designed specifically for live interactive programming

Protection in commodity monolithic operating systems

This dissertation suggests and partially demonstrates that it is feasible to retrofit real privilege separation within commodity operating systems by "nesting" a small memory management protection domain inside a monolithic kernel's single-address space: all the while allowing both domains to operate at the same hardware privilege level. This dissertation also demonstrates a microarchitectural return-integrity protection domain that efficiently asserts dynamic "return-to-sender" semantics for all operating system return control-flow operations. Employing these protection domains, we provide mitigations to large classes of kernel attacks such as code injection and return-oriented programming and deploy information protection policies that are not feasible with existing systems. Operating systems form the foundation of information protection in multiprogramming environments. Unfortunately, today's commodity operating systems employ monolithic kernel design, where any single exploit in the vast code base undermines all information protection in the system because all kernel code operates with full supervisor privileges, meaning that even perfectly secure applications are vulnerable. This dissertation explores an approach that retrofits fundamental information protection design principles into commodity monolithic operating systems, the aim of which is a micro-evolution of commodity system design that incrementally decomposes monolithic operating systems from the ground up, thereby applying microkernel-like security properties for billions of users worldwide. The key contribution is the creation of a new operating system organization, the Nested Kernel Architecture, which "nests" a new, efficient intra-kernel memory isolation mechanism into a traditional monolithic operating system design. Using the Nested Kernel Architecture we introduce write-protection services for kernel developers to deploy security policies in ways not possible in current systems—while greatly reducing the trusted computing base—and demonstrate the value of these services by deploying three special data protection policies. Overall, the Nested Kernel Architecture demonstrates practical in-place protections that require only minor code modifications with minimal run- time overheads