nixos: do not test with a disk without a store

nixos-modules/genode-core.nix

@@ -394,7 +394,7 @@ in {
       bootDriveImage = import ./lib/make-bootable-image.nix {
         inherit config pkgs espImage storeFsImage;
       };
-    in bootDriveImage;
+    in lib.mkIf (config.genode.boot.storeBackend != "tarball") bootDriveImage;
 
     # virtualisation.useEFIBoot = config.genode.boot.storeBackend == "usb";
 

nixos-modules/hardware.nix

@@ -25,15 +25,6 @@ with lib;
         }));
     };
 
-    hardware.genode.platform.policies = lib.mkOption {
-      type = with types; listOf path;
-      default = [ ];
-      description = ''
-        List of policies to append to the Genode platform driver.
-        Type is Init.Config.Policy.Type.
-      '';
-    };
-
     hardware.genode = {
 
       ahci.enable = lib.mkEnableOption "AHCI (SATA) block driver";
@@ -58,11 +49,21 @@ with lib;
 
       };
 
+      platform.policies = lib.mkOption {
+        type = with types; listOf path;
+        default = [ ];
+        description = ''
+          List of policies to append to the Genode platform driver.
+          Type is Init.Config.Policy.Type.
+        '';
       };
 
     };
 
-  config = {
+  };
+
+  config = let cfg = config.hardware.genode;
+  in {
 
     assertions = with builtins;
       let
@@ -99,7 +100,7 @@ with lib;
     hardware.genode.usb.storage.enable = config.genode.boot.storeBackend
       == "usb";
 
-    hardware.genode.usb.enable = config.hardware.genode.usb.storage.enable;
+    hardware.genode.usb.enable = cfg.usb.storage.enable;
 
     hardware.genode.platform.policies = lib.lists.imap0 (i: name:
       builtins.toFile (name + ".platform-policy.dhall") ''
@@ -119,7 +120,7 @@ with lib;
               ]
             }
       '') (builtins.attrNames config.networking.interfaces)
-      ++ (lib.optional config.hardware.genode.ahci.enable
+      ++ (lib.optional cfg.ahci.enable
         (builtins.toFile ("ahci.platform-policy.dhall") ''
           let Genode = env:DHALL_GENODE
 
@@ -131,7 +132,7 @@ with lib;
                     { name = "pci", attributes = toMap { class = "AHCI" } }
                 ]
               }
-        '')) ++ (lib.optional config.hardware.genode.framebuffer.enable
+        '')) ++ (lib.optional cfg.framebuffer.enable
           (builtins.toFile ("framebuffer.platform-policy.dhall") ''
             let Genode = env:DHALL_GENODE
 
@@ -143,7 +144,7 @@ with lib;
                       { name = "pci", attributes = toMap { class = "VGA" } }
                   ]
                 }
-          '')) ++ (lib.optional config.hardware.genode.usb.enable
+          '')) ++ (lib.optional cfg.usb.enable
             (builtins.toFile ("usb.platform-policy.dhall") ''
               let Genode = env:DHALL_GENODE
 
@@ -296,7 +297,7 @@ with lib;
 
     in lib.filterAttrs (n: v: v != null) (nics // sockets);
 
-    genode.core.children.ahci_drv = {
+    genode.core.children.ahci_drv = lib.mkIf cfg.ahci.enable {
       inputs = [ pkgs.genodePackages.ahci_drv ];
       configFile = pkgs.writeText "ahci_drv.dhall" ''
         let Genode = env:DHALL_GENODE
@@ -359,9 +360,8 @@ with lib;
 
     genode.core.children.platform_drv = {
       inputs = [ pkgs.genodePackages.platform_drv ];
-      configFile = let
+      configFile =
-        policies =
+        let policies = map (policy: ", ${policy}") cfg.platform.policies;
-          map (policy: ", ${policy}") config.hardware.genode.platform.policies;
         in pkgs.writeText "platform_drv.dhall" ''
           let Genode = env:DHALL_GENODE
 
@@ -390,12 +390,11 @@ with lib;
         '';
     };
 
-    genode.core.children.usb_drv = let
+    genode.core.children.usb_drv = let toYesNo = b: if b then "yes" else "no";
-      cfg = config.hardware.genode.usb;
+    in mkIf cfg.usb.enable {
-      toYesNo = b: if b then "yes" else "no";
-    in mkIf cfg.enable {
       inputs = [ pkgs.genodePackages.usb_drv ];
-      configFile = builtins.toFile "usb_drv.dhall" ''
+      configFile = with cfg.usb;
+        builtins.toFile "usb_drv.dhall" ''
           let Genode = env:DHALL_GENODE
 
           let XML = Genode.Prelude.XML
@@ -419,10 +418,10 @@ with lib;
 
                     in  Init.Config::{
                         , attributes = toMap
-                          { ehci = "${toYesNo cfg.ehciSupport}"
+                            { ehci = "${toYesNo ehciSupport}"
-                          , ohci = "${toYesNo cfg.ohciSupport}"
+                            , ohci = "${toYesNo ohciSupport}"
-                          , uhci = "${toYesNo cfg.uhciSupport}"
+                            , uhci = "${toYesNo uhciSupport}"
-                          , xhci = "${toYesNo cfg.xhciSupport}"
+                            , xhci = "${toYesNo xhciSupport}"
                             }
                         , content =
                           [ XML.element
@@ -443,8 +442,7 @@ with lib;
         '';
     };
 
-    genode.core.children.usb_block_drv =
+    genode.core.children.usb_block_drv = mkIf cfg.usb.storage.enable {
-      mkIf config.hardware.genode.usb.storage.enable {
       inputs = [ pkgs.genodePackages.usb_block_drv ];
       configFile = builtins.toFile "usb_block_drv.dhall" ''
         let Genode = env:DHALL_GENODE
@@ -470,19 +468,18 @@ with lib;
       '';
     };
 
-    genode.core.children.fb_drv =
+    genode.core.children.fb_drv = mkIf cfg.framebuffer.enable {
-      mkIf config.hardware.genode.framebuffer.enable {
       inputs = with pkgs.genodePackages;
         {
           "boot" = [ boot_fb_drv ];
           "vesa" = [ vesa_drv ];
-          }.${config.hardware.genode.framebuffer.driver};
+        }.${cfg.framebuffer.driver};
       configFile = let
         binary = with pkgs.genodePackages;
           {
             "boot" = "boot_fb_drv";
             "vesa" = "vesa_fb_drv";
-            }.${config.hardware.genode.framebuffer.driver};
+          }.${cfg.framebuffer.driver};
       in builtins.toFile "fb_drv.dhall" ''
         let Genode = env:DHALL_GENODE
 
@@ -504,7 +501,7 @@ with lib;
 
     virtualisation.useBootLoader = config.genode.boot.storeBackend != "tarball";
 
-    virtualisation.qemu.options = lib.optional config.hardware.genode.usb.enable
+    virtualisation.qemu.options = lib.optional cfg.usb.enable
       (lib.optional (pkgs.stdenv.isi686 || pkgs.stdenv.isx86_64) "-usb"
         ++ lib.optional (pkgs.stdenv.isAarch32 || pkgs.stdenv.isAarch64)
         "-device usb-ehci,id=usb0");

nixos-modules/qemu-vm.nix

@@ -23,7 +23,7 @@ let
   # Shell script to start the VM.
   startVM = ''
     #! ${pkgs.buildPackages.runtimeShell}
-
+  '' + lib.optionalString (config.virtualisation.diskImage != null) ''
     NIX_DISK_IMAGE=$(readlink -f ''${NIX_DISK_IMAGE:-${config.virtualisation.diskImage}})
 
     if ! test -w "$NIX_DISK_IMAGE"; then
@@ -36,6 +36,7 @@ let
           ${toString config.virtualisation.diskSize}M || exit 1
     fi
 
+  '' + ''
     # Create a directory for storing temporary data of the running VM.
     if [ -z "$TMPDIR" -o -z "$USE_TMPDIR" ]; then
         TMPDIR=$(mktemp -d nix-vm.XXXXXXXXXX --tmpdir)
@@ -72,7 +73,8 @@ in {
     };
 
     virtualisation.diskImage = mkOption {
-      default = "./${config.system.name}.qcow2";
+      type = with types; nullOr path;
+      default = null;
       description = ''
         Path to the disk image containing the root filesystem.
         The image will be created on startup if it does not