Unify naming of base,root image settings

testing/testing.conf

@@ -36,16 +36,25 @@ LOGFILE=$BUILDDIR/testing.log
 # Directory used for loop-mounts
 LOOPDIR=$BUILDDIR/loop
 
-# Base image settings
-ROOTFSSIZE=1024
-ROOTFSSUITE=wheezy
-ROOTFSARCH=amd64
-ROOTFS=$BUILDDIR/debian-$ROOTFSSUITE-$ROOTFSARCH.qcow2
-ROOTFSMIRROR=http://cdn.debian.net/debian
-ROOTFSCOMPILEDIR=$BUILDDIR/compile
+# Image extension
+IMGEXT=qcow2
 
-# Path to guest images
-ROOTFSDIR=$BUILDDIR/root-fs
+# Base image settings
+# The base image is a pristine OS installation created using debootstrap.
+BASEIMGSIZE=1024
+BASEIMGSUITE=wheezy
+BASEIMGARCH=amd64
+BASEIMG=$BUILDDIR/debian-$BASEIMGSUITE-$BASEIMGARCH.$IMGEXT
+BASEIMGMIRROR=http://cdn.debian.net/debian
+
+# Root image settings
+# The root image is the origin of all guest images. It contains additional
+# test-specific software and patches.
+ROOTIMG=$BUILDDIR/root.$IMGEXT
+ROOTIMGCOMPILEDIR=$BUILDDIR/compile
+
+# Guest images settings
+GUESTIMGDIR=$BUILDDIR/guest-images
 
 # libvirt config
 NBDEV=/dev/nbd0