摘要： Smartphones and tablets are increasingly ubiquitous, and many users rely on multiple mobile devices to accommodate work, personal, and geographic mobility needs. Pervasive access to always-on mobile com- puting has created new security and privacy concerns for mobile devices that often force users to carry multiple devices to meet those needs. The volume and popularity of mobile devices has commingled hard- ware and software design, and created tightly vertically integrated platforms that lock users into a single, vendor-controlled ecosystem. My thesis is that lightweight mechanisms can be added to commodity operat- ing systems to enable multiple virtual phones or tablets to run at the same time on a physical smartphone or tablet device, and to enable apps from multiple mobile platforms, such as iOS and Android, to run together on the same physical device, all while maintaining the low-latency and responsiveness expected of modern mobile devices. This dissertation presents two lightweight operating systems mechanisms, virtualization and binary compatibility, that enable multi-persona mobile computing. First, we present Cells, a mobile virtualization architecture enabling multiple virtual phones, or personas, to run simultaneously on the same physical cellphone in a secure and isolated manner. Cells introduces device namespaces that allow apps to run in a virtualized environment while still leveraging native devices such as GPUs to provide accelerated graphics. Second, we present Cycada, an operating system compatibility architecture that runs applica- tions built for different mobile ecosystems, iOS and Android, together on a single Android device. Cycada introduces kernel-level code adaptation and diplomats to simplify binary compatibility support by reusing existing operating system code and unmodified frameworks and libraries. Both Cells and Cycada have been implemented in Android, and can run multiple Android virtual phones, and a mix of iOS and Android apps on