diff --git a/arch/arm/cpu/armv7/mx5/lowlevel_init.S b/arch/arm/cpu/armv7/mx5/lowlevel_init.S
index 96ebfe2..94de9f1 100644
--- a/arch/arm/cpu/armv7/mx5/lowlevel_init.S
+++ b/arch/arm/cpu/armv7/mx5/lowlevel_init.S
@@ -39,10 +39,14 @@
 	orr r0, r0, #(1 << 23)		/* disable write allocate combine */
 	orr r0, r0, #(1 << 22)		/* disable write allocate */
 
-	cmp r3, #0x10    /* r3 contains the silicon rev */
+#if defined(CONFIG_MX51)
+	ldr r1, =0x0
+	ldr r3, [r1, #ROM_SI_REV]
+	cmp r3, #0x10
 
 	/* disable write combine for TO 2 and lower revs */
 	orrls r0, r0, #(1 << 25)
+#endif
 
 	mcr 15, 1, r0, c9, c0, 2
 .endm /* init_l2cc */