--- /dev/null
+Index: rtems/c/src/lib/libbsp/arm/csb336/startup/bspstart.c
+===================================================================
+--- rtems/c/src/lib/libbsp/arm/csb336/startup/bspstart.c
++++ rtems/c/src/lib/libbsp/arm/csb336/startup/bspstart.c
+@@ -89,6 +89,7 @@ void bsp_pretasking_hook(void)
+ void mmu_set_cpu_async_mode(void);
+ void bsp_start_default( void )
+ {
++#ifdef CONFIG_MC9328MX_ASYNCMCLK
+ int i;
+
+ /* Set the MCU prescaler to divide by 1 */
+@@ -104,6 +105,7 @@ void bsp_start_default( void )
+
+ /* Set the CPU to asynchrous clock mode, so it uses its fastest clock */
+ mmu_set_cpu_async_mode();
++#endif /*CONFIG_MC9328MX_ASYNCMCLK*/
+
+ /* disable interrupts */
+ MC9328MXL_AITC_INTENABLEL = 0;