diff --git a/lib/default.nix b/lib/default.nix
index c34b496..130b1b6 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -38,17 +38,24 @@ in {
 
   x86_64-genode.buildNovaIso = { name, rom }:
     let
+
       inherit (hostPkgs) cdrkit syslinux;
       coreNovaObj = "${testPkgs.genode-base-nova}/lib/core-nova.o";
 
-      addressType = ".quad"; # TODO: 32 or 64 bit?!
+      rom' = (with testPkgs; {
+        init = "${genode-os}/bin/init";
+        "ld.lib.so" = "${depot.base-nova}/lib/ld.lib.so";
+        timer = "${genode-base-nova}/bin/nova_timer_drv";
+      }) // rom;
+
+      addressType = ".quad"; # TODO: 32bit?!
 
       map' = with nixpkgs.lib;
         l: f:
         concatStrings (imap0 (i: v: (f (toString i) v)) l);
 
-      mapNames = map' (builtins.attrNames rom);
-      mapValues = map' (builtins.attrValues rom);
+      mapNames = map' (builtins.attrNames rom');
+      mapValues = map' (builtins.attrValues rom');
 
       modulesAsm = ''
         .set MIN_PAGE_SIZE_LOG2, 12
@@ -96,27 +103,29 @@ in {
       syslinuxDir = "${syslinux}/share/syslinux";
 
     in hostPkgs.stdenv.mkDerivation {
-      name = name + ".iso";
-      preferLocalBuild = true;
-      buildInputs = [ testPkgs.stdenv.cc hostPkgs.cdrkit ];
-      dontUnpack = true;
-      dontConfigure = true;
-      dontBuild = true;
+      name = name + "-iso";
+      passthru = rom;
+      passAsFile = [ "modulesAsm" ];
       inherit modulesAsm;
-      installPhase = ''
+      preferLocalBuild = true;
+      dontUnpack = true;
+
+      buildInputs = [ testPkgs.stdenv.cc hostPkgs.cdrkit ];
+
+      buildPhase = ''
         mkdir -p boot/syslinux
 
         # compile the boot modules into one object file
-        $CC -c -x assembler -o boot_modules.o - <<< $modulesAsm
+        $CC -c -x assembler -o boot_modules.o $modulesAsmPath
 
         # link final image
         $LD -nostdlib \
-          -T${./genode.ld} \
-          -T${./nova-bss.ld} \
-          -z max-page-size=0x1000 \
-          -Ttext=0x100000 -gc-sections \
-          ${coreNovaObj} boot_modules.o \
-            -o boot/image.elf
+        	-T${./genode.ld} \
+        	-T${./nova-bss.ld} \
+        	-z max-page-size=0x1000 \
+        	-Ttext=0x100000 -gc-sections \
+        	${coreNovaObj} boot_modules.o \
+        	-o boot/image.elf
 
         strip boot/image.elf
 
@@ -130,11 +139,22 @@ in {
         	${syslinuxDir}/mboot.c32 \
         	boot/syslinux
         chmod +w boot/syslinux/isolinux.bin
-        mkisofs -o $out \
-        -b syslinux/isolinux.bin -c syslinux/boot.cat \
-        -no-emul-boot -boot-load-size 4 -boot-info-table \
-        -iso-level 2 \
-        boot
+        mkisofs -o iso \
+        	-b syslinux/isolinux.bin -c syslinux/boot.cat \
+        	-no-emul-boot -boot-load-size 4 -boot-info-table \
+        	-iso-level 2 \
+        	boot
+
+        # build test script
+        cat > boot-qemu << EOF
+        #!/bin/sh
+        ${hostPkgs.qemu_test}/bin/qemu-system-x86_64 -cdrom $out/iso -machine q35 \$@
+        EOF
+      '';
+
+      installPhase = ''
+        install -Dm444 iso $out/iso
+        install -Dm555 boot-qemu $out/bin/boot-qemu
       '';
     };
 
diff --git a/tests/driver-nova.nix b/tests/driver-nova.nix
index 461589c..bd98c64 100644
--- a/tests/driver-nova.nix
+++ b/tests/driver-nova.nix
@@ -23,7 +23,7 @@ let
 
   runTests = driver:
     hostPkgs.stdenv.mkDerivation {
-      name = "nova-"+driver.testName;
+      name = "nova-" + driver.testName;
       preferLocalBuild = true;
 
       buildCommand = ''
@@ -43,9 +43,6 @@ let
         {
           inherit testConfig;
           config = ./driver-config.xml;
-          init = "${genode-os}/bin/init";
-          "ld.lib.so" = "${depot.base-nova}/lib/ld.lib.so";
-          timer = "${genode-base-nova}/bin/nova_timer_drv";
         } // bootModules);
 
       iso = lib.x86_64-genode.buildNovaIso {
@@ -58,52 +55,50 @@ let
         # Wait for a specific output of a already running spawned proce
         #
         proc wait_for_output { wait_for_re timeout_value running_spawn_id } {
-        	global output
+          global output
 
-        	if {$wait_for_re == "forever"} {
-        		set timeout -1
-        		interact {
-        			\003 {
-        				send_user "Expect: 'interact' received 'strg+c' and was cancelled\n";
-        				exit
-        			}
-        			-i $running_spawn_id
-        		}
-        	} else {
-        		set timeout $timeout_value
-        	}
+          if {$wait_for_re == "forever"} {
+            set timeout -1
+            interact {
+              \003 {
+              	send_user "Expect: 'interact' received 'strg+c' and was cancelled\n";
+              	exit
+              }
+              -i $running_spawn_id
+            }
+          } else {
+            set timeout $timeout_value
+          }
 
-        	expect {
-        		-i $running_spawn_id -re $wait_for_re { }
-        		eof     { puts stderr "Error: Spawned process died unexpectedly"; exit -1 }
-        		timeout { puts stderr "Error: Test execution timed out"; exit -1 }
-        	}
-        	set output $expect_out(buffer)
+          expect {
+            -i $running_spawn_id -re $wait_for_re { }
+            eof     { puts stderr "Error: Spawned process died unexpectedly"; exit -1 }
+            timeout { puts stderr "Error: Test execution timed out"; exit -1 }
+          }
+          set output $expect_out(buffer)
         }
 
-
         proc run_genode_until {{wait_for_re forever} {timeout_value 0} {running_spawn_id -1}} {
-        	#
-        	# If a running_spawn_id is specified, wait for the expected output
-        	#
-        	if {$running_spawn_id != -1} {
-        		wait_for_output $wait_for_re $timeout_value $running_spawn_id
-        		return
-        	}
+          #
+          # If a running_spawn_id is specified, wait for the expected output
+          #
+          if {$running_spawn_id != -1} {
+            wait_for_output $wait_for_re $timeout_value $running_spawn_id
+            return
+          }
 
-        	global spawn_id
-        	spawn ${hostPkgs.qemu_test}/bin/qemu-system-x86_64 -cdrom ${iso} -nographic \
-        		-machine q35 -m size=${toString qemuMem}
-        	wait_for_output $wait_for_re $timeout_value $spawn_id
+          global spawn_id
+          spawn ${iso}/bin/boot-qemu -nographic -m size=${toString qemuMem}
+          wait_for_output $wait_for_re $timeout_value $spawn_id
         }
 
-	# TODO: not in TCL
-        	global env
-        	set out $env(out)
+        # TODO: not in TCL
+        global env
+        set out $env(out)
 
-        	set fd [open "$out/nix-support/hydra-build-products" w]
-        	puts $fd "file iso ${iso}"
-        	close $fd
+        set fd [open "$out/nix-support/hydra-build-products" w]
+        puts $fd "file iso ${iso}"
+        close $fd
       '';
 
       driver = with hostPkgs;