if not os.access(dev_tun, os.W_OK):
         raise RunQemuError("TUN control device %s is not writable, please fix (e.g. sudo chmod 666 %s)" % (dev_tun, dev_tun))
 
-def get_first_file(cmds):
-    """Return first file found in wildcard cmds"""
-    for cmd in cmds:
-        all_files = glob.glob(cmd)
+def get_first_file(globs):
+    """Return first file found in wildcard globs"""
+    for g in globs:
+        all_files = glob.glob(g)
         if all_files:
             for f in all_files:
                 if not os.path.isdir(f):
                     self.rootfs, self.get('MACHINE'),
                     self.fstype)
         elif not self.rootfs:
-            cmd_name = '%s/%s*.%s' % (self.get('DEPLOY_DIR_IMAGE'), self.get('IMAGE_NAME'), self.fstype)
-            cmd_link = '%s/%s*.%s' % (self.get('DEPLOY_DIR_IMAGE'), self.get('IMAGE_LINK_NAME'), self.fstype)
-            cmds = (cmd_name, cmd_link)
-            self.rootfs = get_first_file(cmds)
+            glob_name = '%s/%s*.%s' % (self.get('DEPLOY_DIR_IMAGE'), self.get('IMAGE_NAME'), self.fstype)
+            glob_link = '%s/%s*.%s' % (self.get('DEPLOY_DIR_IMAGE'), self.get('IMAGE_LINK_NAME'), self.fstype)
+            globs = (glob_name, glob_link)
+            self.rootfs = get_first_file(globs)
             if not self.rootfs:
-                raise RunQemuError("Failed to find rootfs: %s or %s" % cmds)
+                raise RunQemuError("Failed to find rootfs: %s or %s" % globs)
 
         if not os.path.exists(self.rootfs):
             raise RunQemuError("Can't find rootfs: %s" % self.rootfs)
             kernel_match_name = "%s/%s" % (deploy_dir_image, kernel_name)
             kernel_match_link = "%s/%s" % (deploy_dir_image, self.get('KERNEL_IMAGETYPE'))
             kernel_startswith = "%s/%s*" % (deploy_dir_image, self.get('KERNEL_IMAGETYPE'))
-            cmds = (kernel_match_name, kernel_match_link, kernel_startswith)
-            self.kernel = get_first_file(cmds)
+            globs = (kernel_match_name, kernel_match_link, kernel_startswith)
+            self.kernel = get_first_file(globs)
             if not self.kernel:
-                raise RunQemuError('KERNEL not found: %s, %s or %s' % cmds)
+                raise RunQemuError('KERNEL not found: %s, %s or %s' % globs)
 
         if not os.path.exists(self.kernel):
             raise RunQemuError("KERNEL %s not found" % self.kernel)
         dtb = self.get('QB_DTB')
         if dtb:
             deploy_dir_image = self.get('DEPLOY_DIR_IMAGE')
-            cmd_match = "%s/%s" % (deploy_dir_image, dtb)
-            cmd_startswith = "%s/%s*" % (deploy_dir_image, dtb)
-            cmd_wild = "%s/*.dtb" % deploy_dir_image
-            cmds = (cmd_match, cmd_startswith, cmd_wild)
-            self.dtb = get_first_file(cmds)
+            glob_match = "%s/%s" % (deploy_dir_image, dtb)
+            glob_startswith = "%s/%s*" % (deploy_dir_image, dtb)
+            glob_wild = "%s/*.dtb" % deploy_dir_image
+            globs = (glob_match, glob_startswith, glob_wild)
+            self.dtb = get_first_file(globs)
             if not os.path.exists(self.dtb):
-                raise RunQemuError('DTB not found: %s, %s or %s' % cmds)
+                raise RunQemuError('DTB not found: %s, %s or %s' % globs)
 
     def check_bios(self):
         """Check and set bios"""