Final touch-ups before making repository public?

Author: DRNadler

README.md

@@ -46,8 +46,14 @@ On ARM, FreeRTOS ISRs run on the dedicated MSP stack, allocated at top of RAM. T
 To use port_DRN.c, exclude FreeRTOS amazon-freertos/freertos_kernel/portable/GCC/ARM_CM4F/port.c from your build and add port_DRN.c. Ensure you've got required space allocation in your LD, then configure your MSP stack size and enable MSP checking by adding to your FreeRTOSconfig.h:
 
     // DRN ISR (MSP) stack initialization and checking
+    #if !defined(EXTERNC)
+      #if defined(__cplusplus)
+        #define EXTERNC extern "C"
+      #else
+        #define EXTERNC extern
+      #endif
+    #endif
     #define configISR_STACK_SIZE_WORDS (0x100) // in WORDS, must be valid constant for GCC assembler
     #define configSUPPORT_ISR_STACK_CHECK  1   // DRN initialize and check ISR stack
-    UBaseType_t xUnusedISRstackWords( void );  // check unused amount at runtime
-
+    EXTERNC unsigned long /*UBaseType_t*/ xUnusedISRstackWords( void );  // check unused amount at runtime
 # ToDo: Add The Other Tools...

heap_useNewlib_NXP.c

@@ -117,7 +117,7 @@
         if (heap_end == NULL)
             heap_end = &end;
         prev_heap_end = heap_end;
-        if (heap_end + incr > &heap_limit) // of course, always true for FreeRTOS task stacks
+        if (heap_end + incr > &heap_limit) // Fails here: always true for FreeRTOS task stacks
         {
             errno = ENOMEM; // ...so first call inside a FreeRTOS task lands here
             return (caddr_t)-1;

heap_useNewlib_ST.c

@@ -102,7 +102,7 @@
         char *prev_heap_end;
         if (heap_end == 0) heap_end = &end;
         prev_heap_end = heap_end;
-        if (heap_end + incr > stack_ptr) // of course, always true for FreeRTOS task stacks
+        if (heap_end + incr > stack_ptr) // Fails here: always true for FreeRTOS task stacks
         {
             errno = ENOMEM; // ...so first call inside a FreeRTOS task lands here
             return (caddr_t) -1;

port_DRN.c

@@ -1,3 +1,5 @@
+// Includes DRN additions for MSP (ISR) stack-use checking
+
 /*
  * FreeRTOS Kernel V10.2.1
  * Copyright (C) 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.