BitBake User Manual

Table of Contents

• 1 Overview
  • 1.1 Introduction
  • 1.2 History and Goals
  • 1.3 Concepts
    • 1.3.1 Recipes
    • 1.3.2 Configuration Files
    • 1.3.3 Classes
    • 1.3.4 Layers
    • 1.3.5 Append Files
  • 1.4 Obtaining BitBake
  • 1.5 The BitBake Command
    • 1.5.1 Usage and syntax
    • 1.5.2 Examples
      • 1.5.2.1 Executing a Task Against a Single Recipe
      • 1.5.2.2 Executing Tasks Against a Set of Recipe Files
      • 1.5.2.3 Executing a List of Task and Recipe Combinations
      • 1.5.2.4 Generating Dependency Graphs
      • 1.5.2.5 Executing a Multiple Configuration Build
      • 1.5.2.6 Enabling Multiple Configuration Build Dependencies
• 2 Execution
  • 2.1 Parsing the Base Configuration Metadata
  • 2.2 Locating and Parsing Recipes
  • 2.3 Providers
  • 2.4 Preferences
  • 2.5 Dependencies
  • 2.6 The Task List
  • 2.7 Executing Tasks
  • 2.8 Checksums (Signatures)
  • 2.9 Setscene
  • 2.10 Logging
• 3 Syntax and Operators
  • 3.1 Basic Syntax
    • 3.1.1 Basic Variable Setting
    • 3.1.2 Modifying Existing Variables
    • 3.1.3 Line Joining
    • 3.1.4 Variable Expansion
    • 3.1.5 Setting a default value (?=)
    • 3.1.6 Setting a weak default value (??=)
    • 3.1.7 Immediate variable expansion (:=)
    • 3.1.8 Appending (+=) and prepending (=+) With Spaces
    • 3.1.9 Appending (.=) and Prepending (=.) Without Spaces
    • 3.1.10 Appending and Prepending (Override Style Syntax)
    • 3.1.11 Removal (Override Style Syntax)
    • 3.1.12 Override Style Operation Advantages
    • 3.1.13 Variable Flag Syntax
    • 3.1.14 Inline Python Variable Expansion
    • 3.1.15 Unsetting variables
    • 3.1.16 Providing Pathnames
  • 3.2 Exporting Variables to the Environment
  • 3.3 Conditional Syntax (Overrides)
    • 3.3.1 Conditional Metadata
    • 3.3.2 Key Expansion
    • 3.3.3 Examples
  • 3.4 Sharing Functionality
    • 3.4.1 Locating Include and Class Files
    • 3.4.2 inherit Directive
      • 3.4.2.1 inherit_defer Directive
    • 3.4.3 include Directive
    • 3.4.4 include_all Directive
    • 3.4.5 require Directive
    • 3.4.6 INHERIT Configuration Directive
    • 3.4.7 addfragments Directive
  • 3.5 Functions
    • 3.5.1 Shell Functions
    • 3.5.2 BitBake-Style Python Functions
    • 3.5.3 Python Functions
    • 3.5.4 BitBake-Style Python Functions Versus Python Functions
    • 3.5.5 Anonymous Python Functions
    • 3.5.6 Flexible Inheritance for Class Functions
  • 3.6 Tasks
    • 3.6.1 Promoting a Function to a Task
    • 3.6.2 Deleting a Task
    • 3.6.3 Passing Information Into the Build Task Environment
  • 3.7 Variable Flags
  • 3.8 Events
  • 3.9 Variants — Class Extension Mechanism
  • 3.10 Dependencies
    • 3.10.1 Dependencies Internal to the .bb File
    • 3.10.2 Build Dependencies
    • 3.10.3 Runtime Dependencies
    • 3.10.4 Recursive Dependencies
    • 3.10.5 Inter-Task Dependencies
  • 3.11 Functions You Can Call From Within Python
    • 3.11.1 Functions for Accessing Datastore Variables
    • 3.11.2 Other Functions
    • 3.11.3 Extending Python Library Code
    • 3.11.4 Testing and Debugging BitBake Python code
  • 3.12 Task Checksums and Setscene
  • 3.13 Wildcard Support in Variables
• 4 Variable Context
  • 4.1 BitBake’s own configuration
  • 4.2 BitBake configuration
  • 4.3 Layers and files
  • 4.4 Recipes and packages
• 5 File Download Support
  • 5.1 The Download (Fetch)
  • 5.2 The Unpack
  • 5.3 Fetchers
    • 5.3.1 Local file fetcher (file://)
    • 5.3.2 HTTP/FTP wget fetcher (http://, ftp://, https://)
    • 5.3.3 CVS fetcher ((cvs://)
    • 5.3.4 Subversion (SVN) Fetcher (svn://)
    • 5.3.5 Git Fetcher (git://)
    • 5.3.6 Git Submodule Fetcher (gitsm://)
    • 5.3.7 ClearCase Fetcher (ccrc://)
    • 5.3.8 Perforce Fetcher (p4://)
    • 5.3.9 Repo Fetcher (repo://)
    • 5.3.10 Az Fetcher (az://)
    • 5.3.11 GCP Fetcher (gs://)
    • 5.3.12 Crate Fetcher (crate://)
    • 5.3.13 NPM Fetcher (npm://)
    • 5.3.14 NPM shrinkwrap Fetcher (npmsw://)
    • 5.3.15 Other Fetchers
  • 5.4 Auto Revisions
• 6 Variables Glossary
• 7 Hello World Example
  • 7.1 BitBake Hello World
  • 7.2 Obtaining BitBake
  • 7.3 Setting Up the BitBake Environment
  • 7.4 The Hello World Example

---

BitBake Community

Copyright © 2004-2025, Richard Purdie, Chris Larson, and Phil Blundell

<bitbake-devel@lists.openembedded.org>

This work is licensed under the Creative Commons Attribution License. To view a copy of this license, visit http://creativecommons.org/licenses/by/2.5/ or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California 94041, USA.