diff --git a/product/common.mk b/product/common.mk
new file mode 100644
index 00000000..5b0a9589
--- /dev/null
+++ b/product/common.mk
@@ -0,0 +1,14 @@
+PRODUCT_NAME := cyanogen
+PRODUCT_BRAND := cyanogen
+PRODUCT_DEVICE := generic
+
+TARGET_OTA_SCRIPT_MODE = edify
+
+PRODUCT_PROPERTY_OVERRIDES += \
+    ro.rommanager.developerid=cyanogenmod
+
+PRODUCT_PACKAGES += \
+    CMParts
+
+PRODUCT_COPY_FILES += \
+    vendor/cyanogen/CHANGELOG:system/etc/CHANGELOG-CM.txt
diff --git a/product/cyanogen_passion.mk b/product/cyanogen_passion.mk
index 8a1503d0..34c1acc9 100644
--- a/product/cyanogen_passion.mk
+++ b/product/cyanogen_passion.mk
@@ -1,4 +1,7 @@
+# Inherit AOSP device configuration for passion.
 $(call inherit-product, device/htc/passion/full_passion.mk)
+
+# Inherit some common cyanogenmod stuff.
 $(call inherit-product, vendor/cyanogen/product/common.mk)
 
 PRODUCT_NAME := cyanogen_passion
@@ -6,3 +9,12 @@ PRODUCT_BRAND := google
 PRODUCT_DEVICE := passion
 PRODUCT_MODEL := Nexus One
 PRODUCT_MANUFACTURER := HTC
+
+# Set ro.modversion
+ifdef CYANOGEN_NIGHTLY
+    PRODUCT_PROPERTY_OVERRIDES += \
+        ro.modversion=CyanogenMod-6-$(shell date +%m%d%Y)-NIGHTLY-N1
+else
+    PRODUCT_PROPERTY_OVERRIDES += \
+        ro.modversion=CyanogenMod-6.0.0-N1-test0
+endif