{ config, lib, pkgs, modulesPath, ... }:

# Hardware configuration for the primary Raspberry Pi 4 (8 GB).
#
# nixos-raspberrypi's raspberry-pi-4.base module (imported in flake.nix)
# provides everything that nixos-hardware.raspberry-pi-4 previously did:
#   - linuxPackages_rpi4 vendor kernel + matching firmware
#   - u-boot bootloader with /boot/firmware partition management
#   - initrd modules (xhci_pci, usbhid, usb_storage, vc4, pcie_brcmstb, etc.)
#   - config.txt generation
#
# This file adds only host-specific overrides on top of that.
#
# External HD:
#   Set homey.storage.device to the by-id path of your USB drive.
#   Find it with: ls -la /dev/disk/by-id/
#
# TODO: Verify SD card partition labels after first flash.
#   The config assumes labels NIXOS_SD (root) and FIRMWARE (boot).
#   Check with: lsblk -o NAME,LABEL
#   Update fileSystems entries below if they differ.

{
  # tmpfs for /tmp — keep the SD card writes down
  boot.tmp.useTmpfs = true;

  # Filesystems
  fileSystems."/" = {
    device  = "/dev/disk/by-label/NIXOS_SD";
    fsType  = "ext4";
    options = [ "noatime" ];
  };

  fileSystems."/boot/firmware" = {
    device  = "/dev/disk/by-label/FIRMWARE";
    fsType  = "vfat";
    options = [ "fmask=0022" "dmask=0022" ];
  };

  # External HD — device path is set in default.nix via homey.storage.device.
  # storage.nix creates the actual fileSystems entry from that option.

  swapDevices = [];

  # Platform
  nixpkgs.hostPlatform = lib.mkDefault "aarch64-linux";

  # Power management
  powerManagement.cpuFreqGovernor = lib.mkDefault "ondemand";
}