KL25Z: Add low-level up_lowgetc function that can be used to provide an NSH console when the file system (and hence the serial driver) is disabled. From Alan Carvalho de Assis

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)

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 */
 

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)