NixOS Dual-Configuration Setup

A NixOS system with two fully isolated configurations:

1. Dev - Latest stable kernel, web development tooling (Docker, Node.js, direnv)
2. Gaming - Zen kernel, Steam, Lutris, performance tools

Both share a common base: MangoWC (Wayland compositor) + Noctalia Shell, AMD RDNA 4 GPU support, and a shared /home directory with mutable dotfiles.

Target Hardware

Component	Model	Notes
CPU	AMD Ryzen 7 5700G	Zen 3, iGPU available
GPU	AMD RX 9060 XT	RDNA 4, requires Kernel 6.14+, Mesa 25.0+
Motherboard	MSI B550 Tomahawk	Excellent IOMMU groups

Directory Structure

nixos-config/
├── flake.nix                           # Main flake definition
├── flake.lock                          # Auto-generated after first build
├── hosts/
│   └── <hostname>/
│       └── hardware-configuration.nix  # Copy from /etc/nixos/
└── modules/
    ├── common.nix                      # Shared configuration
    ├── dev.nix                         # Development profile
    └── gaming.nix                      # Gaming profile

Prerequisites

1. NixOS installed (minimal install is fine)
2. Flakes enabled in existing config or via: nix-shell -p nixFlakes
3. Know your hostname, username, timezone, and locale

Quick Setup

1. Clone and Prepare

# Clone this repo to your config directory
git clone <this-repo> ~/nixos-config
cd ~/nixos-config

# Replace the placeholder hardware-configuration.nix with your actual one
cp /etc/nixos/hardware-configuration.nix hosts/<hostname>/

2. Replace Placeholders

Edit the following files and replace these placeholders:

Placeholder	Example Value	Files
<hostname>	desktop	flake.nix, modules/common.nix
<username>	john	modules/common.nix, modules/dev.nix, modules/gaming.nix
<timezone>	America/New_York	modules/common.nix
<locale>	en_US.UTF-8	modules/common.nix

Also rename hosts/hostname/ to match your actual hostname.

3. Stage Files in Git

cd ~/nixos-config
git add .

4. Verify Flake

nix flake check
nix flake show

5. Build and Switch

# Build and switch to dev config as main system profile
sudo nixos-rebuild switch --flake .#dev

# Build gaming config as separate boot profile
sudo nixos-rebuild boot --profile-name gaming --flake .#gaming

6. Reboot and Verify

Boot menu should show:

• NixOS (dev) - Default boot
• NixOS (gaming, zen) - Gaming profile

Updating

IMPORTANT: Always update both profiles together to avoid kernel/Mesa version drift:

cd ~/nixos-config
git add .
sudo nixos-rebuild switch --flake .#dev
sudo nixos-rebuild boot --profile-name gaming --flake .#gaming

To update flake inputs:

nix flake update
git add flake.lock
sudo nixos-rebuild switch --flake .#dev
sudo nixos-rebuild boot --profile-name gaming --flake .#gaming

Configuration Summary

Config	Kernel	Key Features
dev	Latest	Docker, Node.js, direnv, dev CLI tools
gaming	Zen	Steam, Lutris, MangoHUD, Gamemode, CoreCtrl
Shared	-	MangoWC, Noctalia, AMD GPU, PipeWire, Firefox

Post-Installation

Change Password

passwd

Setup MangoWC

mkdir -p ~/.config/mango
cp /etc/mango/config.conf ~/.config/mango/config.conf

# Create autostart script
cat > ~/.config/mango/autostart.sh << 'EOF'
#!/bin/bash
qs -c noctalia-shell &
EOF
chmod +x ~/.config/mango/autostart.sh

Add to ~/.config/mango/config.conf:

exec-once="~/.config/mango/autostart.sh"

Auto-start MangoWC from TTY

Add to ~/.bash_profile or ~/.zprofile:

if [[ -z $WAYLAND_DISPLAY ]] && [[ $(tty) == /dev/tty1 ]]; then
    exec mango
fi

GPU Verification

# Verify firmware loaded
dmesg | grep -i "amdgpu" | grep -i "firmware"

# Check GPU detected
lspci | grep VGA

# Verify Vulkan
vulkaninfo | head -30

# Check ray tracing support
vulkaninfo | grep VK_KHR_ray_tracing_pipeline

# Verify OpenCL
clinfo | head -20

Troubleshooting

Flake can't find files

git add .  # Flakes require files to be tracked by git

MangoWC doesn't start

systemctl status seatd
groups  # Ensure user is in 'seat' group

RDNA 4 black screen

dmesg | grep -i "amdgpu" | grep -i "firmware"
uname -r  # Should be 6.14+

Steam doesn't launch

Ensure hardware.graphics.enable32Bit = true; in common.nix.

Games won't launch

cat /proc/sys/vm/max_map_count  # Should be 2147483642 on gaming profile

License

MIT