diff --git a/src/arch/arm/armv4/cache.c b/src/arch/arm/armv4/cache.c
index 729b82c411..e5cf293dce 100644
--- a/src/arch/arm/armv4/cache.c
+++ b/src/arch/arm/armv4/cache.c
@@ -55,6 +55,17 @@ void dcache_invalidate_all(void)
 {
 }
 
+unsigned int dcache_line_bytes(void)
+{
+	/*
+	 * TODO: Implement this correctly. For now we just return a
+	 * reasonable value. It was added during Nyan development and
+	 * may be used in bootblock code. It matters only if dcache is
+	 * turned on.
+	 */
+	return 64;
+}
+
 void dcache_clean_by_mva(void const *addr, size_t len)
 {
 }
diff --git a/src/arch/arm/include/armv4/arch/cache.h b/src/arch/arm/include/armv4/arch/cache.h
index db4379a4c0..6a3f593f28 100644
--- a/src/arch/arm/include/armv4/arch/cache.h
+++ b/src/arch/arm/include/armv4/arch/cache.h
@@ -57,6 +57,9 @@ void dcache_clean_all(void);
 /* dcache invalidate all (on current level given by CCSELR) */
 void dcache_invalidate_all(void);
 
+/* returns number of bytes per cache line */
+unsigned int dcache_line_bytes(void);
+
 /* dcache and MMU disable */
 void dcache_mmu_disable(void);