LessUI-Cores

Build libretro emulator cores for ARM retro handhelds running MinUI/LessUI.

Quick Start

# Build cores for ARM64 devices
make build-arm64

# Build cores for ARM32 devices
make build-arm32

# Build both architectures
make build-all

# Package for distribution
make package-all

Supported Devices

Package	Devices	Architecture
arm32	Miyoo Mini/Plus/A30, RG35XX, Trimui Smart	ARMv7VE + NEON (Cortex-A7)
arm64	RG28xx/35xx/40xx, CubeXX, Trimui	ARMv8-A + NEON (Cortex-A53)

What's Included

35 cores per architecture covering:

• Core Systems: NES, SNES, GB/GBC, GBA, Genesis, PS1, PCE, Neo Geo Pocket, Virtual Boy, Pokemon Mini, PICO-8
• Additional: Atari (2600/5200/7800/Lynx), Game Gear, Sega CD, N64, Dreamcast, PSP, DOS, and more

How It Works

Recipes define which cores to build:

recipes/linux/arm64.yml  →  Fetch sources  →  Build  →  output/arm64/*.so
recipes/linux/arm32.yml  →  Fetch sources  →  Build  →  output/arm32/*.so

Each recipe YAML contains:

1. CPU config - Compiler flags and toolchain settings
2. Core definitions - Repo, commit, and build instructions for each core

Build Commands

# Full builds (1-3 hours each)
make build-arm32          # All ARM32 cores
make build-arm64          # All ARM64 cores
make build-all            # Both architectures

# Single core (for testing)
make core-arm64-gambatte  # Build one core
make core-arm32-flycast

# Packaging
make package-arm64        # Create linux-arm64.zip
make package-all          # Create all zips

# Utilities
make list-cores           # Show available cores
make test                 # Run test suite
make shell                # Open Docker shell
make clean                # Remove all outputs

Adding a Core

1. Find the commit:

   git ls-remote --heads https://github.com/libretro/gambatte-libretro.git | grep master

2. Add to recipes/linux/arm64.yml:

   cores:
     gambatte:
       repo: libretro/gambatte-libretro
       commit: 6924c76ba03dadddc6e97fa3660f3d3bc08faa94
       build_type: make
       makefile: Makefile.libretro
       build_dir: "."
       platform: unix
       so_file: gambatte_libretro.so

3. Test build:

   make core-arm64-gambatte

4. Copy entry to arm32.yml and test that architecture

Updating Cores

Cores with a target field can be auto-updated:

make update-recipes-arm64           # Update all updateable cores
make update-core-arm64-gambatte     # Update specific core
make update-recipes-arm64 DRY=1     # Check what would update

For manually pinned cores, edit the commit field directly.

Build Environment

• Docker: Debian Buster (glibc 2.28 for device compatibility)
• Compiler: GCC 8.3.0
• Toolchains: arm-linux-gnueabihf (ARM32), aarch64-linux-gnu (ARM64)

Project Structure

recipes/linux/          # YAML recipes (source of truth)
  arm32.yml             # ARM32 CPU config + cores
  arm64.yml             # ARM64 CPU config + cores
lib/                    # Ruby build system
  cores_builder.rb      # Main orchestrator
  source_fetcher.rb     # Fetch from GitHub
  core_builder.rb       # Compile cores
scripts/
  build-all             # Build all cores
  build-one             # Build single core
  update-recipes        # Update commit hashes
output/                 # Build outputs (gitignored)
  arm64/*.so            # Built cores
  cores-arm64/          # Fetched sources
  dist/                 # Packaged zips

Releases

Releases are triggered by pushing date-based tags:

make release            # Create and push YYYYMMDD-N tag
make release FORCE=1    # Force recreate today's release

GitHub Actions builds both architectures and creates a release with linux-arm32.zip and linux-arm64.zip.

Requirements

• Docker
• ~5GB disk space per architecture
• 1-3 hours build time per architecture

Documentation

• CLAUDE.md - Detailed developer guide
• docs/adding-cores.md - Step-by-step core addition guide

License

Individual cores have their own licenses (typically GPLv2). See upstream repositories.