diff -Nru a/arch/ppc/boot/simple/misc-prep.c b/arch/ppc/boot/simple/misc-prep.c
--- a/arch/ppc/boot/simple/misc-prep.c	2005-04-04 10:41:25.766786800 +0200
+++ b/arch/ppc/boot/simple/misc-prep.c	2005-04-04 10:47:23.185450904 +0200
@@ -34,7 +34,11 @@
 extern void serial_fixups(void);
 extern struct bi_record *decompress_kernel(unsigned long load_addr,
 		int num_words, unsigned long cksum);
+#ifdef CONFIG_6XX
 extern void disable_6xx_mmu(void);
+#else
+static inline void disable_6xx_mmu(void){}
+#endif
 extern unsigned long mpc10x_get_mem_size(void);
 
 static void