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MicroPython Internals

This chapter covers a tour of MicroPython from the perspective of a developer, contributing to MicroPython. It acts as a comprehensive resource on the implementation details of MicroPython for both novice and expert contributors.

Development around MicroPython usually involves modifying the core runtime, porting or maintaining a new library. This guide describes at great depth, the implementation details of MicroPython including a getting started guide, compiler internals, porting MicroPython to a new platform and implementing a core MicroPython library.

• Getting Started
  • Source control with git
  • Get the code
  • Compile and build the code
    • Required dependencies
    • Building the MicroPython cross-compiler
    • Building the Unix port of MicroPython
    • Building the Windows port
    • Building the STM32 port
  • Building the documentation
  • Running the tests
  • Additional make targets for developers
  • Using ci.sh locally
  • Folder structure
• Writing tests
• The Compiler
  • Adding a grammar rule
  • Adding a lexical token
  • Parsing
  • Compiler passes
    • First pass
    • Second and third passes
    • Fourth pass
  • Emitting bytecode
  • Emitting native code
• Memory Management
  • The object model
  • Allocation of objects
• Implementing a Module
  • Implementing a core module
• Optimizations
  • Frozen bytecode
  • Variables
  • Allocation of memory
• MicroPython string interning
  • Compile-time QSTR generation
  • Run-time QSTR generation
• Maps and Dictionaries
  • Open addressing
  • Linear probing
• The public C API
• Extending MicroPython in C
  • MicroPython external C modules
    • Structure of an external C module
    • Basic example
    • Compiling the cmodule into MicroPython
    • Module usage in MicroPython
  • Native machine code in .mpy files
    • Supported features and limitations
    • Defining a native module
    • Minimal example
    • Compiling the module
    • Module usage in MicroPython
    • Using Picolibc when building modules
    • Further examples
• Porting MicroPython
  • Minimal MicroPython firmware
  • MicroPython Configurations
  • Support for standard input/output
  • Building and running
  • Adding a module to the port