nix-dotfiles/systems/argiletum/disk.nix

{
  disko.devices = {
    disk = {
      # SD card — change device to /dev/sda if booting from USB instead
      main = {
        type = "disk";
        device = "/dev/mmcblk0";
        content = {
          type = "gpt";
          partitions = {
            # Raspberry Pi firmware partition — must be vfat and first
            firmware = {
              size = "256MiB";
              type = "EF00";
              priority = 1;
              content = {
                type = "filesystem";
                format = "vfat";
                mountpoint = "/boot/firmware";
                mountOptions = [
                  "fmask=0077"
                  "dmask=0077"
                ];
              };
            };
            # NixOS boot partition — holds kernels/initrds for each generation
            boot = {
              size = "1GiB";
              priority = 2;
              content = {
                type = "filesystem";
                format = "ext4";
                mountpoint = "/boot";
              };
            };
            # Root filesystem — LUKS-encrypted, unlocked via TPM 2.0 HAT
            root = {
              size = "100%";
              priority = 3;
              content = {
                type = "luks";
                name = "cryptroot";
                settings.allowDiscards = true;
                content = {
                  type = "filesystem";
                  format = "ext4";
                  mountpoint = "/";
                };
              };
            };
          };
        };
      };
    };
  };
}