diff --git a/FreeRTOS/Source/portable/esp8266/port.c b/FreeRTOS/Source/portable/esp8266/port.c
index 690e97e..0aaed7b 100644
--- a/FreeRTOS/Source/portable/esp8266/port.c
+++ b/FreeRTOS/Source/portable/esp8266/port.c
@@ -199,6 +199,13 @@ void vPortEndScheduler( void )
 variable. */
 static unsigned portBASE_TYPE uxCriticalNesting = 0;
 
+/* These nested vPortEnter/ExitCritical macros are called by SDK
+ * libraries in libmain, libnet80211, libpp
+ *
+ * It may be possible to replace the global nesting count variable
+ * with a save/restore of interrupt level, although it's difficult as
+ * the functions have no return value.
+ */
 void vPortEnterCritical( void )
 {
     portDISABLE_INTERRUPTS();
diff --git a/FreeRTOS/Source/portable/esp8266/sdk_compat.c b/FreeRTOS/Source/portable/esp8266/sdk_compat.c
index c48604e..36b6f7c 100644
--- a/FreeRTOS/Source/portable/esp8266/sdk_compat.c
+++ b/FreeRTOS/Source/portable/esp8266/sdk_compat.c
@@ -4,23 +4,6 @@
 #include <string.h>
 #include "FreeRTOS.h"
 
-/* Enable/Disable Interrupts
-
-   Called from many of the linked libraries to protect critical sections.
- */
-
-/*
-void vPortEnterCritical( void )
-{
-    portDISABLE_INTERRUPTS();
-}
-
-void vPortExitCritical( void )
-{
-    portEXIT_CRITICAL();
-}
-*/
-
 /* libc memory management functions.
 
    Many of these are linked from the RTOS SDK blob libraries.