Info
This document outlines the plan to ratify a RISC-V Specification, establishing a solid foundation and clear expectations for the entire specification development lifecycle. The timeline set here will serve as a reference to monitor progress and ensure milestones are met. Investing in a well-prepared plan promotes effective communication, enhances collaboration, and streamlines the process.

About

Specification Name: CHERI
Task Group:
Jira Legacy
server System Jira
serverId 4d3dce95-b4be-35da-b49f-ec8432d8f473
key RVG-148
Task Group Charter: https://github.com/riscv-admin/cheri-tg/blob/main/charter.adoc Charter
Spec Jira:
Jira Legacy
server System Jira
serverId 4d3dce95-b4be-35da-b49f-ec8432d8f473
key RVS-2141

Background

The goal of the CHERI TG is to define a capability-based security extension.

...

Building on over a decade of pioneering research by the University of Cambridge and SRI International, the CHERI technology has been implemented by Arm on the Morello 7nm SoC evaluation platform, and many processors have been developed by academia and the industry (Microsoft, Google, Codasip, lowRISC…)

Overview

Stakeholders Identification

References: Active Groups and Specifications Under Development

...

Security HC as well as Priv+Unpriv IC
CHERI SIG
psABI (to define the new pure-capability ABI)
Architectural Testing (to define a testsuite for CHERI-RISC-V)
Formal modelling (to upstream a CHERI-RISC-V Sail model)
Apps and Tools Software HC
SBI Specification

Design Considerations

The CHERI extension has been designed to be fully binary compatible with existing RISC-V code.

Proof-of-Concept and Tests

Software Ecosystem Impacts

Freeze Checklists

Select one of the options below (ISA or NON-ISA) and complete the table with the required information.

Expand

title	ISA

Item	Description	Plan	Resources
Opcode	Enough opcode encoding to support GCC.	Full support in LLVM: https://github.com/CHERI-Alliance/llvm-project	Codasip+Cambridge Uni
Simulator	Enough simulator support so that basic RISC-V tests can be run. See the policy for more details.	QEMU support implemented: https://github.com/CHERI-Alliance/qemu	Codasip+Cambridge Uni
psABI	ABI extensions (if necessary)	Planned	Jessica Clarke + Alex Richardson
GCC	Support on GCC (optimizations not required)	N/A, using LLVM instead
LLVM	Support on LLVM (optimizations not required)	Full support: https://github.com/CHERI-Alliance/llvm-project	Codasip+Cambridge Uni
RISC-V Test Input	Test configuration input (YAML schema & values, Test Coverage YAML rules, see the policy)
RISC-V Tests	Basic tests that do not cover corner cases. See the policy for more details.	Available on demand	Codasip
RISC-V SAIL	Enablement of the new specification/extension as part of the RISC-V SAIL Golden Model.	Implemented: https://github.com/CHERI-Alliance/sail-cheri-riscv	Codasip