diff --git a/arch/arm/src/cxd56xx/cxd56_serial.c b/arch/arm/src/cxd56xx/cxd56_serial.c
index 6ef147a04e2..4f62145f998 100644
--- a/arch/arm/src/cxd56xx/cxd56_serial.c
+++ b/arch/arm/src/cxd56xx/cxd56_serial.c
@@ -460,6 +460,17 @@ static int up_setup(FAR struct uart_dev_s *dev)
   uint32_t lcr;
   uint32_t cr;
 
+#ifdef CONFIG_CXD56_SUBCORE
+  if (priv->id == 1)
+    {
+      /* In case of SUBCORE, UART1 has been already initialized,
+       * then we don't need to do anything.
+       */
+
+      return OK;
+    }
+#endif
+
   cxd56_uart_setup(priv->id);
 
   /* Init HW */
diff --git a/arch/arm/src/cxd56xx/cxd56_start.c b/arch/arm/src/cxd56xx/cxd56_start.c
index 0518be6c92e..d85f4848606 100644
--- a/arch/arm/src/cxd56xx/cxd56_start.c
+++ b/arch/arm/src/cxd56xx/cxd56_start.c
@@ -303,7 +303,9 @@ void __start(void)
 
   putreg32(0, CXD56_EXCCONF_BASE + 0);
 
+#ifndef CONFIG_CXD56_SUBCORE
   cxd56_lowsetup();
+#endif
   showprogress('A');
 
   /* Clear .bss.  We'll do this inline (vs. calling memset) just to be
@@ -327,7 +329,7 @@ void __start(void)
 
   /* Perform early serial initialization */
 
-#ifdef USE_EARLYSERIALINIT
+#if defined(USE_EARLYSERIALINIT) && !defined(CONFIG_CXD56_SUBCORE)
   arm_earlyserialinit();
 #endif
   showprogress('E');