treewide: only ever set unmergable options via lib.mkDefault

Also extract documentation from raspberry-pi/2/ profile.

acer/aspire/4810t/default.nix

@@ -1,3 +1,5 @@
+{ lib, ... }:
+
 {
   boot = {
     initrd.kernelModules = [ "ata_piix" ];
@@ -15,12 +17,12 @@
   hardware.opengl.driSupport = false;
 
   services.xserver = {
-    enable = true;
-    defaultDepth = 24;
-    videoDriver = "intel";
-    autorun = true;
+    enable = lib.mkDefault true;
+    defaultDepth = lib.mkDefault 24;
+    videoDrivers = [ "intel" ];
+    autorun = lib.mkDefault true;
     synaptics = {
-      enable = true;
+      enable = lib.mkDefault true;
       dev = "/dev/input/event8";
     };
   };

lenovo/ideapad/z510/default.nix

@@ -1,9 +1,8 @@
-{ config, pkgs, ... }:
+{ lib, ... }:
 
 {
-  hardware.cpu.intel.updateMicrocode = true;
+  hardware.cpu.intel.updateMicrocode = lib.mkDefault true;
 
-  # see https://github.com/NixOS/nixpkgs/issues/18356
-  # found buggy driver with method https://wiki.ubuntu.com/DebuggingKernelSuspend
+  # https://github.com/NixOS/nixpkgs/issues/18356
   boot.blacklistedKernelModules = [ "nouveau" ];
 }

microsoft/surface-pro/3/default.nix

@@ -1,8 +1,8 @@
-{ ... }:
+{ lib, ... }:
 
 {
   # to use the type cover in the initrd
   boot.kernelModules = [ "hid-microsoft" ];
 
-  networking.wireless.enable = true;
+  networking.wireless.enable = lib.mkDefault true;
 }

raspberry-pi/2/README.txt

@@ -0,0 +1,19 @@
+imported from https://nixos.org/wiki/Raspberry_Pi_2 **
+
+# Status
+The code in master as of June 2015 should be able to prepare a bootable NixOS for Raspberry PI 2.
+
+There are still some drawbacks:
+
+NixOS does not provide a /boot/config.txt (the FAT32 partition).
+Making NixOS work in the Raspberry PI 2 is mainly the result of the recent work of ambro718, Dezgeg and viric (#nixos@irc.freenode.net).
+
+# Download
+If you want to test, you can flash this 4GB SD image (DOS partition table + fat32 + ext4 rootfs):
+magnet:?xt=urn:btih:0def3f6acb3bceddb22cb24098f58e40e2853ec2&dn=rpi2-nixos-4b09501f2-img.xz&tr=udp%3A%2F%2Fopen.demonii.com%3A1337&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80
+
+Then you should be able to nixos-rebuild any configuration.nix changes.
+
+The image is the result of a "nixos-install" alone. No root password has been set, and it does not include a nixpkgs checkout or channel.
+
+In fact I (viric) created the FS into a NBD, not a real SD, to create this image.

raspberry-pi/2/default.nix

@@ -1,64 +1,32 @@
-/** imported from https://nixos.org/wiki/Raspberry_Pi_2 **
-
-# Status
-The code in master as of June 2015 should be able to prepare a bootable NixOS for Raspberry PI 2.
-
-There are still some drawbacks:
-
-NixOS does not provide a /boot/config.txt (the FAT32 partition).
-Making NixOS work in the Raspberry PI 2 is mainly the result of the recent work of ambro718, Dezgeg and viric (#nixos@irc.freenode.net).
-
-# Download
-If you want to test, you can flash this 4GB SD image (DOS partition table + fat32 + ext4 rootfs):
-magnet:?xt=urn:btih:0def3f6acb3bceddb22cb24098f58e40e2853ec2&dn=rpi2-nixos-4b09501f2-img.xz&tr=udp%3A%2F%2Fopen.demonii.com%3A1337&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80
-
-Then you should be able to nixos-rebuild any configuration.nix changes.
-
-The image is the result of a "nixos-install" alone. No root password has been set, and it does not include a nixpkgs checkout or channel.
-
-In fact I (viric) created the FS into a NBD, not a real SD, to create this image.
-
-*/
-
-{ pkgs, config, lib, ...}:
+{ lib, pkgs, ...}:
 
 {
-  boot.consoleLogLevel = 7;
-  boot.loader.grub.enable = false;
-  boot.loader.generationsDir.enable = false;
-  boot.loader.raspberryPi.enable = true;
-  boot.loader.raspberryPi.version = 2;
-  boot.extraTTYs = [ "ttyAMA0" ];
-  boot.kernelPackages = pkgs.linuxPackages_rpi;
-  boot.kernelParams = [
-    #"coherent_pool=6M"
-    #"smsc95xx.turbo_mode=N"
-    "dwc_otg.lpm_enable=0"
-    "console=ttyAMA0,115200"
-    "rootwait"
-    #"console=tty1"
-    "elevator=deadline"
-  ];
-
-  # cpufrequtils doesn't build on ARM
-  powerManagement.enable = false;
-
-  services.xserver.enable = false;
-  services.openssh.enable = true;
-
-  services.nixosManual.enable = false;
-
-  nixpkgs.config = {
-    # Since https://github.com/NixOS/nixpkgs/commit/f0b634c7e838cdd65ac6f73933c99af3f38d0fa8
-    nixpkgs.config.platform = lib.systems.platforms.raspberrypi2;
-    # Earlier than that, use this:
-    # platform = pkgs.platforms.raspberrypi2;
-    # Also be aware of this issue if you're encountering infinite recursion:
-    # https://github.com/NixOS/nixpkgs/issues/24170
-
-    allowUnfree = true;
+  boot = {
+    consoleLogLevel = lib.mkDefault 7;
+    extraTTYs = [ "ttyAMA0" ];
+    kernelPackages = lib.mkDefault pkgs.linuxPackages_rpi;
+    kernelParams = [
+      "dwc_otg.lpm_enable=0"
+      "console=ttyAMA0,115200"
+      "rootwait"
+      "elevator=deadline"
+    ];
+    loader = {
+      grub.enable = lib.mkDefault false;
+      generationsDir.enable = lib.mkDefault false;
+      raspberryPi = {
+        enable = lib.mkDefault true;
+	version = lib.mkDefault 2;
+      };
+    };
   };
 
   nix.buildCores = 4;
-  nix.binaryCaches = [ ];
+
+  nixpkgs.config.platform = lib.systems.platforms.raspberrypi2;
+
+  # cpufrequtils doesn't build on ARM
+  powerManagement.enable = lib.mkDefault false;
+
+  services.openssh.enable = lib.mkDefault true;
 }

supermicro/x10sll-f/default.nix

@@ -1,9 +1,7 @@
 { config, pkgs, ... }:
 
 {
-  environment.systemPackages = with pkgs; [
-    ipmitool
-  ];
+  environment.systemPackages = with pkgs; [ ipmitool ];
 
   boot.kernelModules = [ "jc42" "ipmi_devintf" "ipmi_si" "tpm_rng" ];