The RISC-V Instruction Set Manual Volume 2: Privileged Architecture Version 1.7
Andrew S. Waterman, Yunsup Lee, Rimas R. Avizienis, David A. Patterson, Krste Asanović · 2015
Abstract : This document describes the RISC-V privileged architecture, which covers all aspects of RISC-V systems beyond the user-level ISA, including privileged instructions as well as additional functionality required for running operating systems and attaching external devices.