diff --git a/arch/arm/ops.S b/arch/arm/ops.S
index a858fa3..96b7445 100644
--- a/arch/arm/ops.S
+++ b/arch/arm/ops.S
@@ -211,3 +211,13 @@
 	mcr		p15, 0, r0, c7, c10, 5
 #endif
 	bx		lr
+
+/*void dsb(void) */
+FUNCTION(dsb)
+#if ARM_CPU_CORTEX_A8
+	dsb		sy
+#elif ARM_CPU_ARM1136
+	mov		r0, #0
+	mcr		p15, 0, r0, c7, c10, 4
+#endif
+	bx		lr