Modify fileSystem."/boot" in different file, not hardware-configuration.nix

Help
1

Is it possible to add below text to my default.nix. I’d like to keep hardware-configurations ‘generated-only’.

default.nix

...
  fileSystems."/boot1" = {
    # nofail: Makes it possible to boot with only 1 mirror present.
    options = [ "nofail" ];
  };
  fileSystems."/boot2" = {
    # nofail: Makes it possible to boot with only 1 mirror present.
    options = [ "nofail" ];
  };
...

hardware-configuration.nix

# Do not modify this file!  It was generated by ‘nixos-generate-config’
# and may be overwritten by future invocations.  Please make changes
# to /etc/nixos/configuration.nix instead.
{ config, lib, pkgs, modulesPath, ... }:
...
  fileSystems."/boot1" =
    { device = "/dev/disk/by-uuid/32C2-1234";
      fsType = "vfat";
    };
  fileSystems."/boot2" =
    { device = "/dev/disk/by-uuid/32C3-1234";
      fsType = "vfat";
    };
...
2

Yes. Attribute sets are usually* merged recursively, and it does not matter where the fields are defined.

Just try it out.

*It is possible to override merging mechanics for custom types, and so far for me it was always clear from context what to expect. Check the implementation when in doubt.

3

Tried it, it works.
Thanks