Ensure the PIC32 interrupt stack is 8 byte aligned for all values of configISR_STACK_SIZE.

FreeRTOS/Source/portable/MPLAB/PIC32MX/port.c

@@ -188,11 +188,11 @@ volatile UBaseType_t uxInterruptNesting = 0x01;
 UBaseType_t uxSavedTaskStackPointer = 0;
 
 /* The stack used by interrupt service routines that cause a context switch. */
-StackType_t xISRStack[ configISR_STACK_SIZE ] = { 0 };
+__attribute__ ((aligned(8))) StackType_t xISRStack[ configISR_STACK_SIZE ] = { 0 };
 
 /* The top of stack value ensures there is enough space to store 6 registers on
 the callers stack, as some functions seem to want to do this. */
-const StackType_t * const xISRStackTop = &( xISRStack[ configISR_STACK_SIZE - 7 ] );
+const StackType_t * const xISRStackTop = &( xISRStack[ ( configISR_STACK_SIZE & ~portBYTE_ALIGNMENT_MASK ) - 8 ] );
 
 /*-----------------------------------------------------------*/
 

FreeRTOS/Source/portable/MPLAB/PIC32MX/portmacro.h

@@ -198,7 +198,7 @@ extern void vPortClearInterruptMaskFromISR( UBaseType_t );
 
 	/*-----------------------------------------------------------*/
 
-	#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31 - _clz( ( uxReadyPriorities ) ) )
+	#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31UL - _clz( ( uxReadyPriorities ) ) )
 
 #endif /* taskRECORD_READY_PRIORITY */
 

FreeRTOS/Source/portable/MPLAB/PIC32MZ/port.c

@@ -1,5 +1,5 @@
 /*
-    FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd.
+    FreeRTOS V9.0.1 - Copyright (C) 2017 Real Time Engineers Ltd.
     All rights reserved
 
     VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
@@ -71,8 +71,12 @@
  * Implementation of functions defined in portable.h for the PIC32MZ port.
   *----------------------------------------------------------*/
 
+/* Microchip specific headers. */
 #include <xc.h>
 
+/* Standard headers. */
+#include <string.h>
+
 /* Scheduler include files. */
 #include "FreeRTOS.h"
 #include "task.h"
@@ -189,11 +193,13 @@ volatile UBaseType_t uxInterruptNesting = 0x01;
 UBaseType_t uxSavedTaskStackPointer = 0;
 
 /* The stack used by interrupt service routines that cause a context switch. */
-StackType_t xISRStack[ configISR_STACK_SIZE ] = { 0 };
+__attribute__ ((aligned(8))) StackType_t xISRStack[ configISR_STACK_SIZE ] = { 0 };
 
 /* The top of stack value ensures there is enough space to store 6 registers on
-the callers stack, as some functions seem to want to do this. */
-const StackType_t * const xISRStackTop = &( xISRStack[ configISR_STACK_SIZE - 7 ] );
+the callers stack, as some functions seem to want to do this.  8 byte alignment
+is required to allow double word floating point stack pushes generated by the
+compiler. */
+const StackType_t * const xISRStackTop = &( xISRStack[ ( configISR_STACK_SIZE & ~portBYTE_ALIGNMENT_MASK ) - 8 ] );
 
 /* Saved as part of the task context. Set to pdFALSE if the task does not
  require an FPU context. */

FreeRTOS/Source/portable/MPLAB/PIC32MZ/portmacro.h

@@ -209,7 +209,7 @@ extern void vPortClearInterruptMaskFromISR( UBaseType_t );
 
 	/*-----------------------------------------------------------*/
 
-	#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31 - _clz( ( uxReadyPriorities ) ) )
+	#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31UL - _clz( ( uxReadyPriorities ) ) )
 
 #endif /* taskRECORD_READY_PRIORITY */