zion/modules/device.nix

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

with pkgs;

{
  # A bunch of boot parameters needed for optimal runtime on RPi 4B
  boot.kernelPackages = linuxPackages_rpi4;
  boot.kernelParams = [
    "zfs.zfs_arc_max=134217728"
    "console=TTYAMA0,115200"
    "console=tty1"
    "8250.nr_uarts=1"
    "iomem=relaxed"
    "strict-devmem=0"
  ];

  # Enable SATA-HAT GPIO features
  boot.loader = {
    grub.enable = false;
    generic-extlinux-compatible.enable = lib.mkForce false;
    raspberryPi = {
      enable = true;
      version = 4;
      firmwareConfig = ''
        iomem=relaxed
        strict-devmem=0
      '';
    };
  };

  # Load PWM hardware timers
  hardware.raspberry-pi."4".pwm0.enable = true;

  # Enable I2C
  hardware.raspberry-pi."4".i2c1.enable = true;
}