diff --git a/lib/cpus/aarch64/cortex_a55.S b/lib/cpus/aarch64/cortex_a55.S
index 018c9db..20d5fe4 100644
--- a/lib/cpus/aarch64/cortex_a55.S
+++ b/lib/cpus/aarch64/cortex_a55.S
@@ -39,6 +39,49 @@
 	b	cpu_rev_var_ls
 endfunc check_errata_768277
 
+	/* ------------------------------------------------------------------
+	 * Errata Workaround for Cortex A55 Errata #778703.
+	 * This applies only to revision r0p0 of Cortex A55 where L2 cache is
+	 * not configured.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0-x17
+	 * ------------------------------------------------------------------
+	 */
+func errata_a55_778703_wa
+	/*
+	 * Compare x0 against revision r0p0 and check that no private L2 cache
+	 * is configured
+	 */
+	mov	x17, x30
+	bl	check_errata_778703
+	cbz	x0, 1f
+	mrs	x1, CORTEX_A55_CPUECTLR_EL1
+	orr	x1, x1, #CORTEX_A55_CPUECTLR_EL1_L1WSCTL
+	msr	CORTEX_A55_CPUECTLR_EL1, x1
+	mrs	x1, CORTEX_A55_CPUACTLR_EL1
+	orr	x1, x1, #CORTEX_A55_CPUACTLR_EL1_DISABLE_WRITE_STREAMING
+	msr	CORTEX_A55_CPUACTLR_EL1, x1
+	isb
+1:
+	ret	x17
+endfunc errata_a55_778703_wa
+
+func check_errata_778703
+	mov	x16, x30
+	mov	x1, #0x00
+	bl	cpu_rev_var_ls
+	/*
+	 * Check that no private L2 cache is configured
+	 */
+	mrs	x1, CORTEX_A55_CLIDR_EL1
+	and	x1, x1, CORTEX_A55_CLIDR_EL1_CTYPE3
+	cmp	x1, #0
+	mov	x2, #ERRATA_NOT_APPLIES
+	csel	x0, x0, x2, eq
+	ret	x16
+endfunc check_errata_778703
+
 func cortex_a55_reset_func
 	mov	x19, x30
 
@@ -54,6 +97,11 @@
 	bl	errata_a55_768277_wa
 #endif
 
+#if ERRATA_A55_778703
+	mov	x0, x18
+	bl	errata_a55_778703_wa
+#endif
+
 	ret	x19
 endfunc cortex_a55_reset_func
 
@@ -88,6 +136,7 @@
 	 */
 	report_errata ERRATA_DSU_936184, cortex_a55, dsu_936184
 	report_errata ERRATA_A55_768277, cortex_a55, 768277
+	report_errata ERRATA_A55_778703, cortex_a55, 778703
 
 	ldp	x8, x30, [sp], #16
 	ret
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 2ada0be..ee316b7 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -83,6 +83,10 @@
 # only to revision r0p0 of the Cortex A55 cpu.
 ERRATA_A55_768277	?=0
 
+# Flag to apply erratum 778703 workaround during reset. This erratum applies
+# only to revision r0p0 of the Cortex A55 cpu.
+ERRATA_A55_778703	?=0
+
 # Flag to apply erratum 806969 workaround during reset. This erratum applies
 # only to revision r0p0 of the Cortex A57 cpu.
 ERRATA_A57_806969	?=0
@@ -156,6 +160,10 @@
 $(eval $(call assert_boolean,ERRATA_A55_768277))
 $(eval $(call add_define,ERRATA_A55_768277))
 
+# Process ERRATA_A55_778703 flag
+$(eval $(call assert_boolean,ERRATA_A55_778703))
+$(eval $(call add_define,ERRATA_A55_778703))
+
 # Process ERRATA_A57_806969 flag
 $(eval $(call assert_boolean,ERRATA_A57_806969))
 $(eval $(call add_define,ERRATA_A57_806969))