diff --git a/arch/powerpc/mm/40x_mmu.c b/arch/powerpc/mm/40x_mmu.c
index 08dfa8e6d86..65abfcfaaa9 100644
--- a/arch/powerpc/mm/40x_mmu.c
+++ b/arch/powerpc/mm/40x_mmu.c
@@ -84,8 +84,8 @@ void __init MMU_init_hw(void)
 	 * vectors and the kernel live in real-mode.
 	 */
 
-        mtspr(SPRN_DCCR, 0xF0000000);	/* 512 MB of data space at 0x0. */
-        mtspr(SPRN_ICCR, 0xF0000000);	/* 512 MB of instr. space at 0x0. */
+        mtspr(SPRN_DCCR, 0xFFFF0000);	/* 2GByte of data space at 0x0. */
+        mtspr(SPRN_ICCR, 0xFFFF0000);	/* 2GByte of instr. space at 0x0. */
 }
 
 #define LARGE_PAGE_SIZE_16M	(1<<24)