m8c for the H700 SoC (RG35XX* & RG40XX* devices)

This repository contains a Dockerfile and build script for compiling the m8c client for the DirtyWave M8 Headless firmware and necessary kernel modules for Anbernic's Linux-based handheld console devices based on the Allwinner h700 chip. Broadly, these are the RG35XX* & RG40XX* devices

Note on IRL Anbernic device tests: I have only tested this on an Anbernic RG35XXSP & RG40XXV myself, but others in the Discord community have basically run this on other RG35XX* & RG40XX* devices

Note on custom firmware on ANbernic device: This uses tooling from the Knulli CFW project. It might work on other custom firmwares, but I haven't tested them (yet)

Overview

The idea behind this is to provide a platform that makes it relatively easy for most people to compile a runnable executable of the M8 Tracker software for handheld gaming consoles. With a bit more tinkering, this could be made more flexible so that it's easy to build m8c for other devices and/or other firmware.

Requirements

• Git
• Docker

Dependencies

This version builds using:

• Linux kernel v4.9.170
• Knulli RG35XX Plus/H/SP/2024 toolchain rg35xx-plush-sdk-20240421/aarch64-buildroot-linux-gnu_sdk-buildroot
• m8c v1.7.8

Usage

On Linux/macOS:

1. Clone this repository:

   git clone https://github.com/jamesMcMeex/m8c-rg35xx-knulli.git

2. Go into the directory:

   cd m8c-rg35xx-knulli

3. Run the build script:

    ./build.sh

On Windows:

1. Clone this repository:

   git clone https://github.com/jamesMcMeex/m8c-rg35xx-knulli.git

2. Go into the directory:

   cd m8c-rg35xx-knulli

3. Run Docker commands directly:

   docker buildx create --name m8c-builder --driver docker-container --bootstrap
   docker buildx use m8c-builder
   docker buildx build --platform linux/amd64 --load -f Dockerfile.x86_64 -t m8c-knulli .
   mkdir -p output
   docker run -v ${pwd}/output:/build/compiled m8c-knulli

The script automatically detects system architecture on Linux/macOS and uses the appropriate build configuration. After the build process completes, you'll find the compiled files in a new output/ directory located inside the source directory.

What's Included

• build.sh: Main build script that detects architecture and manages the build process
• Dockerfile.arm64 and Dockerfile.x86_64: Sets up the build environment for different architectures
• build_script.arm64.sh and build_script.x86_64.sh: Architecture-specific build scripts

Build Process

The build process includes the following steps:

1. Downloads and extracts the Linux kernel source (version 4.9.170)
2. Downloads and extracts the Knulli ARM64 toolchain
3. Downloads the Knulli Linux config file for RG35XX* devices
4. Downloads and extracts the m8c project
5. Configures and builds the necessary kernel modules
6. Builds m8c
7. Collects all built files and creates a startup script

Output

After a successful build, you'll find the following in the output directory:

• A folder named m8c with the m8c executable and the compiled kernel modules (cdc-acm.ko, snd-hwdep.ko, snd-usbmidi-lib.ko, snd-usb-audio.ko) inside
• m8c.sh startup script

Installation on device (Knulli CFW-specific)

• Locate the roms/ports folder in the partition used to store ROMs (this will either be the SHARE volume when using a single SD card setup, or on the second SD card, if you've set up Knulli on your device this way)
• Drop the m8c folder and the m8c.sh script into this location
• (Optional) Add the m8c application to the gamelist.xml file to make it a bit more pretty in the Knulli UI

Troubleshooting

If you encounter issues running m8c on your device, here are some common problems and solutions:

"Permission denied" Errors

When you see "Permission denied" or the app won't launch:

1. Make sure both files are executable by running these commands in the ports/m8c directory:

   chmod +x m8c.sh
   chmod +x m8c/m8c

2. For kernel module loading issues, you may need to set correct permissions:

   chmod 644 m8c/*.ko

"Failed to start PipeWire loopback" Error

If you get audio-related errors:

1. First make sure your M8 is properly connected via USB
2. Try unplugging and reconnecting your M8
3. If the error persists, you may need to restart your device

Getting Help

If you're still having issues:

1. Check existing Issues to see if others have solved your problem
2. When creating a new issue, please include:
   • Your device model (RG35XX+, RG35XXSP, etc.)
   • The exact error message you're seeing
   • Steps you've already tried

Customization

You can modify the build process by adjusting any of these files:

• Architecture-specific Dockerfiles (Dockerfile.arm64, Dockerfile.x86_64) to change the build environment
• Build scripts (build_script.arm64.sh, build_script.x86_64.sh) to modify the build process
• Main build script (build.sh) to change how architecture detection and Docker builds are handled

Common customizations include:

• Changing the kernel version
• Using a different toolchain
• Updating the M8C repository URL or version
• Modifying kernel module configurations

Contributing

Feel free to fork the repository, make your changes, and submit a pull request.

Acknowledgments

• DirtyWave for creating the M8 tracker
• laamaa for developing m8c
• mnml for writing the script that gave me the inspiration to hack
• knulli-cfw for the RG35XX Plus custom firmware work
• All the other people who contributed to the mountain of software that makes things run on a dinky little computer

License

MIT License