Composing Abstractions using the null-Kernel

ions imply choice, one that OS designers must confront when designing a programming interface to expose. Traditional monolithic kernel designers choose a high-level portable interface that necessarily hides many hardware details. On the other extreme, designs such as the Exokernel optimize for performance and low-level hardware access. Abstraction choices have further implications in how easily and quickly new hardware and application models can be supported. In this paper, we describe the null-Kernel, a new model for structuring system software that attempts to relieve OS designers of this choice and enable access to and composition of OS interfaces at different levels of abstraction. The null-Kernel is designed to address the growing need to easily provide high-level programming interfaces to new Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from permissions@acm.org. HotOS ’19, May 13–15, 2019, Bertinoro, Italy © 2019 Copyright held by the owner/author(s). Publication rights licensed