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Architecture

Family mruby Architecture

Family mruby is a personal project implementing a "Multi-VM architecture based on MicroRuby," built on top of FreeRTOS. The system enables concurrent execution of multiple Ruby virtual machines.

The architecture consists of two main components:

  • fmrb-core (ESP32-S3 with PSRAM): The main processing board running the Family mruby OS Framework. Hosts multiple FreeRTOS tasks, each running independent VMs:

    • OS Manager (MicroRuby): System management and coordination
    • MicroRuby App: User applications written in Ruby
    • Guest Language Apps: Support for other scripting languages like Lua

  • fmrb-audio-graphics (ESP32 with PSRAM): Dedicated board handling audio/graphics processing, including an Audio/Graphics Controller, NES APU emulator, and LovyanGFX library. Communicates with the core board via UART.

Multi-VM Structure

The system follows a "one task = one VM" design philosophy, leveraging FreeRTOS task functionality to run multiple VMs in parallel. Each VM operates independently with its own stack and memory space, ensuring isolation and stability.

Key Features

  • OS Foundation: Built on FreeRTOS running on ESP-IDF
  • VM Implementation: Uses MicroRuby VM based on mruby (not PicoRuby based on mruby/c)
  • Independent Memory Pools: Each VM has its own memory allocator handle, preventing system-wide memory fragmentation and isolating failures to individual VMs
  • Multi-language Support: Primary support for MicroRuby, with experimental Lua support and planned MicroPython integration

Target Hardware

Designed for ESP32 devices with multi-megabyte PSRAM (e.g., ESP32-S3-WROOM-1-N16R8). Custom development boards are under development.