WIP: system.img generation.

devices/asus-flo/default.nix

@@ -14,5 +14,5 @@
     };
   };
 
-  mobile.system.type = "android-bootimg";
+  mobile.system.type = "android-device";
 }

modules/system-types.nix

@@ -11,6 +11,9 @@ let
   stage-1 = config.mobile.boot.stage-1;
 
   build_types = {
+    android-device = pkgs.callPackage ../systems/android-device.nix {
+      inherit config;
+    };
     android-bootimg = pkgs.callPackage ../systems/bootimg.nix {
       inherit device_config;
       # XXX : this feels like a hack

systems/android-device.nix

@@ -0,0 +1,46 @@
+{
+  config
+  , pkgs
+}:
+with pkgs;
+let
+  device_config = config.mobile.device;
+  hardware_config = config.mobile.hardware;
+
+  inherit (config.mobile.boot) stage-1;
+
+  inherit (hardware_config) ram;
+  device_name = device_config.name;
+  device_info = device_config.info;
+
+  android-bootimg = pkgs.callPackage ./bootimg.nix {
+    inherit device_config;
+    initrd = pkgs.callPackage ./initrd.nix { inherit device_config stage-1; };
+  };
+  android-system =
+    (
+      (import (pkgs.path + "/nixos"))
+      {
+        #system = "armv7l-linux";
+        #system = config.nixpkgs.pkgs.targetPlatform.system;
+        configuration = import (./system-android.nix) { mobile_config = config; };
+      }
+    ).config.system.build.systemImage
+    ;
+in
+stdenv.mkDerivation {
+  name = "nixos-mobile_${device_name}_combined";
+
+  src = builtins.filterSource (path: type: false) ./.;
+  unpackPhase = "true";
+
+  buildInputs = [
+    linux
+  ];
+
+  installPhase = ''
+      mkdir -p $out/
+      cp ${android-bootimg} $out/boot.img
+      cp ${android-system} $out/system.img
+  '';
+}

systems/system-android.nix

@@ -0,0 +1,124 @@
+# This module creates a system.img file built and sized to flash to an android-device.
+#
+# The derivation for the image will be placed in
+# config.system.build.system_img
+
+# FIXME : this is a bit of a hack.
+
+{
+  mobile_config
+}:
+
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  rootfsImage = import <nixpkgs/nixos/lib/make-ext4-fs.nix> {
+    inherit pkgs;
+    inherit (config.systemImage) storePaths;
+    volumeLabel = "NIXOS_SD";
+  };
+in
+{
+  options.systemImage = {
+    imageBaseName = mkOption {
+      default = "nixos-system";
+      description = ''
+        Prefix of the name of the generated image file.
+      '';
+    };
+
+    storePaths = mkOption {
+      type = with types; listOf package;
+      example = literalExample "[ pkgs.stdenv ]";
+      description = ''
+        Derivations to be included in the Nix store in the generated SD image.
+      '';
+    };
+
+    bootSize = mkOption {
+      type = types.int;
+      default = 120;
+      description = ''
+        Size of the /boot partition, in megabytes.
+      '';
+    };
+  };
+
+  config = {
+    fileSystems = {
+      "/" = {
+        device = "/dev/disk/by-label/NIXOS_SD";
+        fsType = "ext4";
+      };
+    };
+
+    boot.kernelPackages =
+    lib.makeExtensible (self: with self; {
+      inherit (mobile_config.mobile.device.info) kernel;
+    })
+    ;#pkgs.linuxPackagesFor mobile_config.mobile.device.info.kernel;
+
+    systemImage.storePaths = [ config.system.build.toplevel ];
+
+    system.build.systemImage = rootfsImage;
+    #pkgs.stdenv.mkDerivation {
+    #  name = "mobile-nixos_system-android_system.img";
+
+    #  buildInputs = with pkgs; [ e2fsprogs mtools libfaketime utillinux ];
+
+    #  buildCommand = ''
+    #    cp "${rootfsImage}" "$img"
+    #  '';
+    #};
+
+    boot.postBootCommands = ''
+      # On the first boot do some maintenance tasks
+      if [ -f /nix-path-registration ]; then
+        # Figure out device names for the boot device and root filesystem.
+        rootPart=$(readlink -f /dev/disk/by-label/NIXOS_SD)
+        # bootDevice=$(lsblk -npo PKNAME $rootPart)
+        # 
+        # # Resize the root partition and the filesystem to fit the disk
+        # echo ",+," | sfdisk -N2 --no-reread $bootDevice
+        # ${pkgs.parted}/bin/partprobe
+        ${pkgs.e2fsprogs}/bin/resize2fs $rootPart
+
+        # Register the contents of the initial Nix store
+        ${config.nix.package.out}/bin/nix-store --load-db < /nix-path-registration
+
+        # nixos-rebuild also requires a "system" profile and an /etc/NIXOS tag.
+        touch /etc/NIXOS
+        ${config.nix.package.out}/bin/nix-env -p /nix/var/nix/profiles/system --set /run/current-system
+
+        # Prevents this from running on later boots.
+        rm -f /nix-path-registration
+      fi
+    '';
+
+    # FIXME https://github.com/ElvishJerricco/cross-nixos-aarch64/blob/master/configuration.nix
+    security.polkit.enable = false;
+    services.udisks2.enable = false;
+    programs.command-not-found.enable = false;
+    system.boot.loader.kernelFile = lib.mkForce "Image";
+    services.nixosManual.enable = lib.mkOverride 0 false;
+    nix.checkConfig = false;
+    services.klogd.enable = false;
+
+    nixpkgs.crossSystem = mobile_config.nixpkgs.crossSystem;
+    system.nixos.stateVersion = "18.09";
+
+    systemd.services.sshd.wantedBy = lib.mkOverride 0 ["multi-user.target"];
+
+    # https://github.com/ElvishJerricco/cross-nixos-aarch64/blob/master/sd-image-aarch64.nix
+    boot.loader.grub.enable = false;
+    boot.loader.generic-extlinux-compatible.enable = true;
+    boot.consoleLogLevel = lib.mkDefault 7;
+    users.extraUsers.root.initialHashedPassword = "";
+
+    # HACK!
+    # Removing `(isYes "MODULES")` would be preferrable.
+    system.requiredKernelConfig = lib.mkForce [];
+  };
+}