Add comprehensive RISC-V support to NixOS configurations

[LarsArtmann]

🎯 Objective

Add comprehensive RISC-V architecture support to our NixOS configurations to enable deployment on RISC-V hardware and virtualization environments.

📋 Background & Research Required

RISC-V is an open-source instruction set architecture that's gaining significant traction in:

• Embedded systems and IoT devices
• Laptop computers (like the VisionFive 2, Roma, etc.)
• Server environments
• Virtualization and cloud deployments

🔍 Research Tasks

1. Current RISC-V Support in NixOS

• Research current RISC-V support status in NixOS/nixpkgs
• Identify which packages are available for RISC-V
• Document any limitations or missing packages
• Check if Home Manager fully supports RISC-V

2. Hardware Compatibility

• Research popular RISC-V development boards and SBCs
• Identify common RISC-V hardware components (GPU, WiFi, etc.)
• Document any special kernel requirements for RISC-V

3. Virtualization Support

• Research QEMU RISC-V virtualization support
• Check Docker/podman RISC-V container support
• Document any special virtualization requirements

🚀 Implementation Plan

Phase 1: Foundation

• Create RISC-V specific configuration files
• Add RISC-V architecture detection to flake.nix
• Implement basic RISC-V system configuration
• Add RISC-V specific kernel parameters

Phase 2: Package Support

• Create RISC-V specific package configurations
• Identify and document any package limitations
• Implement cross-compilation support if needed
• Add RISC-V development tools

Phase 3: Optimization

• Optimize configuration for RISC-V performance characteristics
• Add RISC-V specific security considerations
• Implement RISC-V aware memory management
• Test and validate on actual RISC-V hardware if available

Phase 4: Integration

• Integrate RISC-V support with existing Ghost Systems framework
• Add RISC-V specific type assertions
• Update documentation with RISC-V deployment guides
• Add CI/CD pipelines for RISC-V testing

🛠️ Technical Considerations

Architecture Detection

# Example of how we might detect RISC-V architecture
system = if pkgs.stdenv.hostPlatform.isRiscV64 then "riscv64-linux" else ...;

Package Compatibility

• Many packages may need architecture-specific conditionals
• Some packages may be unavailable for RISC-V
• Performance optimizations specific to RISC-V may be needed

Cross-Compilation

• May need to set up cross-compilation environments
• Toolchain support for RISC-V development
• Bootstrap considerations for minimal systems

📊 Success Metrics

1. ✅ Flake can build for RISC-V target
2. ✅ Basic system boots on RISC-V hardware/emulator
3. ✅ Essential packages (git, curl, editors) available
4. ✅ Ghost Systems framework works on RISC-V
5. ✅ Documentation covers RISC-V deployment
6. ✅ CI/CD pipeline validates RISC-V configurations

🎖️ Priority Levels

🔴 High Priority

• Basic RISC-V configuration support
• Core package availability verification
• Documentation for getting started

🟡 Medium Priority

• Performance optimizations
• Development toolchain setup
• Cross-compilation support

🟢 Low Priority

• Specialized hardware support
• Advanced performance tuning
• CI/CD integration

📚 Resources & References

• NixOS RISC-V Wiki
• RISC-V Official Site
• Nixpkgs RISC-V Support
• QEMU RISC-V Support

🤝 Contribution Guidelines

This is a significant architectural enhancement that will require:

• Careful research and planning
• Incremental implementation approach
• Thorough testing on real hardware when possible
• Comprehensive documentation
• Community feedback integration

Contributors should start with research and documentation updates before making large code changes.

[LarsArtmann]

🔍 Research Update: RISC-V Support in Nixpkgs

Based on my research, here's what I found about RISC-V support in NixOS/nixpkgs:

📊 Current Support Status

Tier 3 Platform Support

• RISC-V is officially supported at Tier 3 level in Nixpkgs
• This means: Most popular packages work, native bootstrap tools available, cross-build toolchains in binary cache
• Caveat: Updates might break builds, no channel-blocking jobs on Hydra CI

🏗️ Available RISC-V Platforms

1. riscv64-unknown-linux-gnu - Primary 64-bit RISC-V with GNU/Linux
2. riscv32-unknown-linux-gnu - 32-bit RISC-V with GNU/Linux
3. riscv64-unknown-linux-musl - 64-bit RISC-V with musl libc
4. riscv64-none-elf - Bare-metal 64-bit RISC-V (newlib)
5. riscv32-none-elf - Bare-metal 32-bit RISC-V (newlib)

💻 Hardware Support

Official Support: None yet (not in mainline channels)
Community Support: Several boards available:

• StarFive VisionFive & VisionFive 2
• STAR64
• Lichee Pi 4A
• Hifive Unmatched

🔄 Implementation Strategy

For our setup, I recommend:

1. Start with QEMU emulation for testing without hardware
2. Focus on riscv64-unknown-linux-gnu as primary target
3. Use binary caches to avoid building everything from source
4. Implement modular architecture detection in our flake.nix

📝 Next Steps for Implementation

1. ✅ Research completed
2. 🔄 Create architecture detection in flake.nix
3. 🔄 Add RISC-V system configurations
4. 🔄 Integrate with Ghost Systems framework
5. 🔄 Add binary cache configuration
6. 🔄 Test with QEMU emulation

🔧 Technical Requirements

# Example structure for our implementation
riscv64 = nixpkgs.lib.nixosSystem {
  system = "riscv64-linux";
  specialArgs = { /* Ghost Systems injection */ };
  modules = [
    ./dotfiles/nixos/configuration.nix
    ./dotfiles/riscv64/configuration.nix  # RISC-V specific
    home-manager.nixosModules.home-manager
    # ... other modules
  ];
};

This research gives us a solid foundation to proceed with implementation. The Tier 3 support means we should expect some limitations, but the core toolchain and popular packages should work well.

Ready to proceed with Phase 1 implementation?