diff --git a/arch/arm/src/kl/Make.defs b/arch/arm/src/kl/Make.defs
index 2fa6049bf6d..4bbc09f2d97 100644
--- a/arch/arm/src/kl/Make.defs
+++ b/arch/arm/src/kl/Make.defs
@@ -68,7 +68,7 @@ CMN_CSRCS += up_dumpnvic.c
 endif
 
 CHIP_ASRCS  =
-CHIP_CSRCS  = kl_clockconfig.c kl_gpio.c kl_idle.c kl_irq.c kl_irqprio.c
+CHIP_CSRCS  = kl_clockconfig.c kl_gpio.c kl_idle.c kl_irq.c kl_irqprio.c kl_lowgetc.c
 CHIP_CSRCS += kl_lowputc.c kl_serial.c kl_start.c kl_timerisr.c kl_cfmconfig.c
 
 ifeq ($(CONFIG_NUTTX_KERNEL),y)
diff --git a/arch/arm/src/kl/kl_serial.c b/arch/arm/src/kl/kl_serial.c
index 10f4f7d6e62..faf9a7106c8 100644
--- a/arch/arm/src/kl/kl_serial.c
+++ b/arch/arm/src/kl/kl_serial.c
@@ -60,6 +60,7 @@
 
 #include "kl_config.h"
 #include "kl_lowputc.h"
+#include "kl_lowgetc.h"
 #include "chip.h"
 #include "kl_gpio.h"
 #include "chip/kl_uart.h"
@@ -955,5 +956,19 @@ int up_putc(int ch)
   return ch;
 }
 
+/****************************************************************************
+ * Name: up_getc
+ *
+ * Description:
+ *   Provide priority, low-level access to support OS debug writes
+ *
+ ****************************************************************************/
+
+int up_getc(void)
+{
+  /* Check for LF */
+
+  return kl_lowgetc();
+}
 #endif /* USE_SERIALDRIVER */
 
diff --git a/arch/arm/src/kl/kl_start.c b/arch/arm/src/kl/kl_start.c
index 46f505c9368..940d7240ec4 100644
--- a/arch/arm/src/kl/kl_start.c
+++ b/arch/arm/src/kl/kl_start.c
@@ -94,7 +94,7 @@ const uint32_t g_idle_topstack = IDLE_STACK;
  *
  ****************************************************************************/
 
-#if defined(CONFIG_DEBUG) && defined(HAVE_SERIAL_CONSOLE)
+#if defined(CONFIG_DEBUG)
 #  define showprogress(c) kl_lowputc((uint32_t)c)
 #else
 #  define showprogress(c)