diff -Nru linux/arch/ppc/boot/simple/misc-prep.c linux-2.6.10/arch/ppc/boot/simple/misc-prep.c
--- linux/arch/ppc/boot/simple/misc-prep.c	2004-12-24 22:33:51.000000000 +0100
+++ linux-2.6.10/arch/ppc/boot/simple/misc-prep.c	2005-01-09 16:30:59.938766448 +0100
@@ -34,7 +34,9 @@
 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);
+#endif
 extern unsigned long mpc10x_get_mem_size(void);
 
 static void
@@ -152,9 +154,11 @@
 		hold_residual->VitalProductData.Reserved5 = 0xdeadbeef;
 	}
 
+	#ifdef CONFIG_6XX
 	/* Now go and clear out the BATs and ensure that our MSR is
 	 * correct .*/
 	disable_6xx_mmu();
+	#endif
 
 	/* Make r3 be a pointer to the residual data. */
 	return (unsigned long)hold_residual;