diff --git a/defaults/main.yml b/defaults/main.yml
index 2332061..12b15ba 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -4,8 +4,14 @@ base__extra_packages: []
 # - foo
 # - bar
 
+# should we add additional package source?
 base__add_ethz: "{{ add_ethz }}"
+# add nonfree/firmware packages?
+base__pkg_non_free_firmware: "{{ base_pkg_non_free_firmware }}"
+base__pkg_contrib: "{{ base_pkg_contrib }}"
 
+# optionaly print some OS vars
+base__print_os_vars: "{{ print_os_vars }}"
 
 
 
diff --git a/tasks/main.yml b/tasks/main.yml
index a33ef8f..3076136 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -9,6 +9,7 @@
   when:
     - ansible_os_family == 'Debian'
     - base__add_ethz | bool
+    - ansible_architecture == 'x86_64'
 
 - name: Install common base packages [Debian]
   become: yes
diff --git a/tasks/sources.yml b/tasks/sources.yml
index cc1dc31..ca07657 100644
--- a/tasks/sources.yml
+++ b/tasks/sources.yml
@@ -1,6 +1,6 @@
 ---
-- name: Install some common Debian specific packages
-  become: yes
+- name: Install requirements to add packages
+  become: true
   apt:
     package:
       - debian-goodies
@@ -12,62 +12,32 @@
   when:
     - ansible_machine != 'armv6l' and ansible_distribution_release != 'wheezy'
 
-- name: add eth zurich apt
+- name: add eth zurich apt (main)
   become: true
   apt_repository:
     repo: deb https://debian.ethz.ch/debian/ {{ ansible_distribution_release }} main
     state: present
   when:
-    - not base_pkg_non_free_firmware | bool
-    - not base_pkg_contrib | bool
-    - add_ethz | bool
-    - ansible_distribution == 'Debian'
+    - not base__pkg_non_free_firmware | bool
+    - not base__pkg_contrib | bool
     - ansible_machine != 'armv6l' and ansible_distribution_release != 'wheezy'
 
-- name: add eth zurich apt
+- name: add eth zurich apt (main non-free)
   become: true
   apt_repository:
     repo: deb-src https://debian.ethz.ch/debian/ {{ ansible_distribution_release }} main non-free
     state: present
   when:
-    - base_pkg_non_free_firmware | bool
-    - not base_pkg_contrib | bool
-    - add_ethz | bool
-    - ansible_distribution == 'Debian'
+    - base__pkg_non_free_firmware | bool
+    - not base__pkg_contrib | bool
     - ansible_machine != 'armv6l' and ansible_distribution_release != 'wheezy'
 
-- name: remove eth zurich apt
-  become: true
-  apt_repository:
-    repo: deb-src https://debian.ethz.ch/debian/ {{ ansible_distribution_release }} main non-free
-    state: absent
-  when:
-    - base_pkg_non_free_firmware | bool
-    - not base_pkg_contrib | bool
-    - not add_ethz | bool
-    - ansible_distribution == 'Debian'
-    - ansible_machine != 'armv6l' and ansible_distribution_release != 'wheezy'
-
-- name: add eth zurich apt + contrib + non-free
+- name: add eth zurich apt (main contrib non-free)
   become: true
   apt_repository:
     repo: deb-src https://debian.ethz.ch/debian/ {{ ansible_distribution_release }} main contrib non-free
     state: present
   when:
-    - base_pkg_non_free_firmware | bool
-    - base_pkg_contrib | bool
-    - add_ethz | bool
-    - ansible_distribution == 'Debian'
-    - ansible_machine != 'armv6l' and ansible_distribution_release != 'wheezy'
-
-- name: remove eth zurich apt + contrib + non-free
-  become: true
-  apt_repository:
-    repo: deb-src https://debian.ethz.ch/debian/ {{ ansible_distribution_release }} main contrib non-free
-    state: absent
-  when:
-    - base_pkg_non_free_firmware | bool
-    - base_pkg_contrib | bool
-    - not add_ethz | bool
-    - ansible_distribution == 'Debian'
+    - base__pkg_non_free_firmware | bool
+    - base__pkg_contrib | bool
     - ansible_machine != 'armv6l' and ansible_distribution_release != 'wheezy'