Ext Schema

v0.1

Auto-generated

This page is generated from ext_schema.json by the schema doc generator. To update this page, edit the schema file and run bin/chore gen schema-docs.

An ISA extension defines a named set of instructions, CSRs, and behaviors that can be implemented by a RISC-V processor. Each extension has one or more versioned releases, with various ratification states (development, frozen, public-review, ratification-ready, ratified, or nonstandard-released).

Key Fields

• name: Short identifier used throughout the database (e.g., I, M, Zicsr, Smstateen)
• long_name: Human-readable one-line description
• description: Full AsciiDoc documentation of the extension
• type: Whether the extension is unprivileged or privileged
• versions: Array of versioned releases, each with a state and optional ratification_date
• requirements: Optional condition that must be true for the extension to be implementable (e.g., requires another extension)
• company: Organization that developed the extension (defaults to RISC-V International for standard extensions)
• doc_license: License for the extension documentation

Quick Start

Minimal Extension (Zicsr):

"$schema": ext_schema.json#
kind: extension
name: Zicsr
long_name: Control and status register instructions
description: Control and status register instructions
type: unprivileged
versions:
- version: 2.0.0
  state: ratified
  ratification_date: 2019-04

Properties

Property	Type	Required	Description
$schema	string (const: ext_schema.json#)	✓	Schema reference - must be ext_schema.json#
kind	string (const: extension)	✓	Document type identifier - must be extension
name	Extension name (e.g., I, M, Zicsr, Smstateen)	✓
long_name	string	✓	One-line human-readable name for the extension (e.g., Address generation, Bit Manipulation)
description	string | Array<conditional_text>	✓	Full AsciiDoc documentation of the extension. May include multiple paragraphs, code examples, and cross-references.
type	unprivileged | privileged	✓	Privilege level of the extension. unprivileged extensions add instructions or behaviors accessible in user mode; privileged extensions add supervisor- or machine-mode functionality.
versions	Array<object> ↓ schema	✓	Ordered list of versioned releases of this extension, from oldest to newest.
rvi_jira_issue	string		JIRA issue number tracking this extension in the RISC-V International issue tracker
company	A company		Organization that developed this extension. Omit for RISC-V International standard extensions.
doc_license	License that applies to the textual documentation for this extension		License for the extension documentation
requirements	A condition (YAML structure or IDL function). See the conditions reference for details.		Condition that must be true for this extension to be implementable. If the condition is false, the extension cannot be implemented. Typically used to express that one extension requires another (e.g., D requires F).
cert_normative_rules	Architecturally visible behaviors requiring validation by certification tests

versions item schema

Property	Type	Required	Description
version	string	✓	Version number in MAJOR.MINOR.PATCH format (e.g., 1.0.0, 2.1.0)
state	development | frozen | public-review | ratification-ready | ratified | nonstandard-released	✓	Ratification state of this version. See spec_state in schema_defs for all possible values and their meanings.
repositories	Array<object>		Source repositories where this version of the extension is developed
ratification_date	One of: string | string | null		Month when this version was ratified, in YYYY-MM format. Use unknown if the date is not recorded. Required when state is ratified.
release_date	One of: string | string | null
changes	Array<string>		List of changes introduced in this version relative to the previous version
url	string		URL to the ratified specification document (e.g., a PDF on the RISC-V website)
contributors	Array<object>		People who contributed to this version of the extension
requirements	object | object | object | object | object | object		Additional condition that must be true for this specific version to be implementable, beyond any requirements on the extension overall. If the condition is false, this version cannot be implemented.

Tooling field

$source is an optional field set automatically by UDB tooling to record the file path this object was loaded from. You do not need to set it manually.

Examples

Extension with Requirements (B)

"$schema": ext_schema.json#
kind: extension
name: B
long_name: Bit Manipulation
description: The B standard extension comprises instructions provided by the Zba,
  Zbb, and Zbs extensions.
type: unprivileged
company:
  name: RISC-V International
  url: https://riscv.org
doc_license:
  name: Creative Commons Attribution 4.0 International License
  url: https://creativecommons.org/licenses/by/4.0/
versions:
- version: 1.0.0
  state: ratified
  ratification_date: 2024-04
  url: https://drive.google.com/file/d/1SgLoasaBjs5WboQMaU3wpHkjUwV71UZn/view
  requirements:
    extension:
      allOf:
      - name: Zba
        version: "= 1.0.0"
      - name: Zbb
        version: "= 1.0.0"
      - name: Zbs
        version: "= 1.0.0"

Schema Information

Property	Value
Version	v0.1
JSON Schema Version	Draft 07