--- a/configure.ac	Tue May 25 13:32:43 2010 +0200
+++ b/configure.ac	Tue May 25 14:12:02 2010 +0200
@@ -513,6 +513,30 @@
 fi
 
 #------------------------------------------------------------------------------
+# Read alias address from register
+#------------------------------------------------------------------------------
+
+AC_ARG_ENABLE([regalias],
+    AS_HELP_STRING([--enable-regalias],
+                   [Read alias adresses from register (default: no)]),
+    [
+        case "${enableval}" in
+            yes) regalias=1
+                ;;
+            no) regalias=0
+                ;;
+            *) AC_MSG_ERROR([Invalid value for --enable-regalias])
+                ;;
+        esac
+    ],
+    [regalias=0]
+)
+
+if test "x${regalias}" = "x1"; then
+    AC_DEFINE([EC_REGALIAS], [1], [Read alias adresses from register])
+fi
+
+#------------------------------------------------------------------------------
 # Command-line tool
 #-----------------------------------------------------------------------------
 

--- a/master/fsm_slave_scan.c	Tue May 25 13:32:43 2010 +0200
+++ b/master/fsm_slave_scan.c	Tue May 25 14:12:02 2010 +0200
@@ -52,7 +52,9 @@
 void ec_fsm_slave_scan_state_datalink(ec_fsm_slave_scan_t *);
 void ec_fsm_slave_scan_state_sii_size(ec_fsm_slave_scan_t *);
 void ec_fsm_slave_scan_state_sii_data(ec_fsm_slave_scan_t *);
+#ifdef EC_REGALIAS
 void ec_fsm_slave_scan_state_regalias(ec_fsm_slave_scan_t *);
+#endif
 void ec_fsm_slave_scan_state_preop(ec_fsm_slave_scan_t *);
 void ec_fsm_slave_scan_state_sync(ec_fsm_slave_scan_t *);
 void ec_fsm_slave_scan_state_pdos(ec_fsm_slave_scan_t *);
@@ -61,7 +63,9 @@
 void ec_fsm_slave_scan_state_error(ec_fsm_slave_scan_t *);
 
 void ec_fsm_slave_scan_enter_datalink(ec_fsm_slave_scan_t *);
+#ifdef EC_REGALIAS
 void ec_fsm_slave_scan_enter_regalias(ec_fsm_slave_scan_t *);
+#endif
 void ec_fsm_slave_scan_enter_preop(ec_fsm_slave_scan_t *);
 void ec_fsm_slave_scan_enter_pdos(ec_fsm_slave_scan_t *);
 
@@ -694,7 +698,15 @@
         }
     }
 
+#ifdef EC_REGALIAS
     ec_fsm_slave_scan_enter_regalias(fsm);
+#else
+    if (slave->sii.mailbox_protocols & EC_MBOX_COE) {
+        ec_fsm_slave_scan_enter_preop(fsm);
+    } else {
+        fsm->state = ec_fsm_slave_scan_state_end;
+    }
+#endif
     return;
 
 end:
@@ -703,13 +715,12 @@
     fsm->state = ec_fsm_slave_scan_state_error;
 }
 
-
-/*****************************************************************************/
-
-/**
-   Slave scan entry function: REGALIAS.
-*/
-
+/*****************************************************************************/
+
+#ifdef EC_REGALIAS
+
+/** Slave scan entry function: REGALIAS.
+ */
 void ec_fsm_slave_scan_enter_regalias(
         ec_fsm_slave_scan_t *fsm /**< slave state machine */
         )
@@ -727,9 +738,8 @@
 
 /*****************************************************************************/
 
-/**
-   Slave scan state: REGALIAS.
-*/
+/** Slave scan state: REGALIAS.
+ */
 void ec_fsm_slave_scan_state_regalias(
         ec_fsm_slave_scan_t *fsm /**< slave state machine */
         )
@@ -754,6 +764,7 @@
         EC_SLAVE_DBG(slave, 1, "Read alias %u from register.\n",
                 slave->effective_alias);
     }
+
     if (slave->sii.mailbox_protocols & EC_MBOX_COE) {
         ec_fsm_slave_scan_enter_preop(fsm);
     } else {
@@ -761,6 +772,8 @@
     }
 }
 
+#endif // defined EC_REGALIAS
+
 /*****************************************************************************/
 
 /** Enter slave scan state PREOP.