Reduced MS/TP MAX_APDU to use 480 by default in examples (#683)

* Reduced MS/TP MAX_APDU to 480 from 1476 so that devices not use new MS/TP extended frame types which older routers do not understand.

* Added extra objects to STM32F4xx example to elicit edge cases in object-list for testing.

ports/stm32f4xx/stm32f4xx.ld

@@ -4,6 +4,16 @@ MEMORY
     flash (RX) : ORIGIN = 0x08000000, LENGTH = 512k
 }
 
+_estack = 0x20000000 + 128k - 4; /* End of SRAM */
+    
+/* Generate a link error if heap and stack don't fit into RAM */
+_Min_Heap_Size = 48K;
+/* Analysis from MAP file and Stack Usage (su) +
+   adjust _Min_Heap_Size until linker error: sram overflowed by x bytes
+   _Min_Heap_Size = _Min_Heap_Size - x
+*/
+_Min_Stack_Size = 16K;
+
 SECTIONS
 {
     .text :
@@ -22,11 +32,10 @@ SECTIONS
         *(.gnu.linkonce.r.*)
         . = ALIGN(4);
         _etext = .;
-		_sidata = _etext;
+        _sidata = _etext;
         PROVIDE(etext = .);
-     		_fini = . ;
-				*(.fini)
-
+        _fini = . ;
+        *(.fini)
     } >flash
 
     .data : AT (_etext)
@@ -40,20 +49,20 @@ SECTIONS
         _edata = .;
     } >sram
 
-		.ARM.extab :
-		{
-		    *(.ARM.extab*)
-		} >sram
+    .ARM.extab :
+    {
+        *(.ARM.extab*)
+    } >sram
 
-		__exidx_start = .;
-		.ARM.exidx :
-		{
-		    *(.ARM.exidx*)
-		} >sram
-		__exidx_end = .;
+    __exidx_start = .;
+    .ARM.exidx :
+    {
+        *(.ARM.exidx*)
+    } >sram
+    __exidx_end = .;
 
     .bss (NOLOAD) : {
-		. = ALIGN(4);
+        . = ALIGN(4);
         /* This is used by the startup in order to initialize the .bss secion */
         _sbss = .;
         *(.bss .bss.*)
@@ -63,6 +72,19 @@ SECTIONS
         _ebss = .;
     } >sram
 
-    end = .;
-    PROVIDE( _estack = 0x20010000 );
+    PROVIDE ( end = _ebss );
+    PROVIDE ( _end = _ebss );
+
+    /* User_heap_stack section, used to check that there is enough RAM left */
+    ._user_heap_stack :
+    {
+        . = ALIGN(4);
+        . = . + _Min_Heap_Size;
+        _user_heap_end = .;
+        . = . + _Min_Stack_Size;
+        . = ALIGN(4);
+    } >sram
+
+    PROVIDE(_heap_limit = _user_heap_end);
+    PROVIDE(_stack_limit = _estack);
 }