Just tidy up the RX port files.

Source/portable/Renesas/RX600/port.c

@@ -63,45 +63,44 @@
 #include "string.h"
 
 /* Hardware specifics. */
-#include <machine.h>
 #include "iodefine.h"
 
 /*-----------------------------------------------------------*/
 
-/* Tasks should start with interrupts enabled, therefore PSW is set with U,I,PM 
+/* Tasks should start with interrupts enabled and in Supervisor mode, therefore 
-flags set and IPL clear. */
+PSW is set with U and I set, and PM and IPL clear. */
-/* 
- U = 1 User stack pointer.
- I = 1 Interrupts enabled.
- PM = 0 Supervisor mode.
- IPL = 0 All interrupt priorities enabled.
-*/
 #define portINITIAL_PSW     ( ( portSTACK_TYPE ) 0x00030000 )
 #define portINITIAL_FPSW    ( ( portSTACK_TYPE ) 0x00000100 )
 
 /*-----------------------------------------------------------*/
 
 /*
- * 
+ * Function to start the first task executing - written in asm code as direct
+ * access to registers is required. 
  */
-void vPortYield( void );
+static void prvStartFirstTask( void );
 
 /*
- * Function to start the first task executing.
+ * Software interrupt handler.  Performs the actual context switch (saving and
+ * restoring of registers).  Written in asm code as direct register access is
+ * required.
  */
-void vPortStartFirstTask( void );
-
-void vPortPendContextSwitch( void );
-
-static void prvStartFirstTask( void );
-
 static void prvYieldHandler( void );
 
+/*
+ * The entry point for the software interrupt handler.  This is the function
+ * that calls the inline asm function prvYieldHandler().  It is installed in 
+ * the vector table, but the code that installs it is in prvYieldHandler rather
+ * than using a #pragma.
+ */
 void vSoftwareInterruptISR( void );
 
 /*-----------------------------------------------------------*/
 
+/* This is accessed by the inline assembler functions so is file scope for
+convenience. */
 extern void *pxCurrentTCB;
+extern void vTaskSwitchContext( void );
 
 /*-----------------------------------------------------------*/
 
@@ -117,6 +116,12 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
  	*pxTopOfStack = portINITIAL_PSW;
 	pxTopOfStack--;
 	*pxTopOfStack = ( portSTACK_TYPE ) pxCode;
+	
+	/* When debugging it can be useful if every register is set to a known
+	value.  Otherwise code space can be saved by just setting the registers
+	that need to be set. */
+	#ifdef USE_FULL_REGISTER_INITIALISATION
+	{
 		pxTopOfStack--;
 		*pxTopOfStack = 0xffffffff;	/* r15. */
 		pxTopOfStack--;
@@ -146,6 +151,13 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
 		pxTopOfStack--;
 		*pxTopOfStack = 0x22222222;
 		pxTopOfStack--;
+	}
+	#else
+	{
+		pxTopOfStack -= 15;
+	}
+	#endif
+	
 	*pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* R1 */
 	pxTopOfStack--;				
 	*pxTopOfStack = portINITIAL_FPSW;
@@ -223,9 +235,11 @@ static void prvStartFirstTask( void )
 #pragma interrupt ( vTickISR( vect = _VECT( configTICK_VECTOR ), enable ) )
 void vTickISR( void )
 {
-	/* Clear the interrupt. */
+	/* Increment the tick, and perform any processing the new tick value
+	necessitates. */
 	vTaskIncrementTick();
 	
+	/* Only select a new task if the preemptive scheduler is being used. */
 	#if( configUSE_PREEMPTION == 1 )
 		taskYIELD();
 	#endif
@@ -250,7 +264,7 @@ static void prvYieldHandler( void )
 	/* Move the data that was automatically pushed onto the interrupt stack when
 	the interrupt occurred from the interrupt stack to the user stack.  
 	
-	R15 is saved before it is used. */
+	R15 is saved before it is clobbered. */
 	PUSH.L	R15
 	
 	/* Read the user stack pointer. */
@@ -260,7 +274,7 @@ static void prvYieldHandler( void )
 	SUB		#12, R15
 	MVTC	R15, USP
 	
-	/* Copy the data accross. */
+	/* Copy the data across. */
 	MOV.L	[ R0 ], [ R15 ] ; R15
 	MOV.L 	4[ R0 ], 4[ R15 ]  ; PC
 	MOV.L	8[ R0 ], 8[ R15 ]  ; PSW
@@ -271,14 +285,16 @@ static void prvYieldHandler( void )
 	/* All the rest of the registers are saved directly to the user stack. */
 	SETPSW	U
 
-	/* Save the rest of the registers (R15 has been saved already. */
+	/* Save the rest of the general registers (R15 has been saved already). */
-	PUSHM	R1-R14 		; General purpose registers. 
+	PUSHM	R1-R14
-	MVFC	FPSW, R15 	; Floating point status word.
+	
+	/* Save the FPSW and accumulator. */
+	MVFC	FPSW, R15
 	PUSH.L	R15
-	MVFACHI	R15 		; Accumulator
+	MVFACHI	R15
 	PUSH.L	R15
-	MVFACMI	R15 		; Accumulator
+	MVFACMI	R15	; Middle order word.
-	SHLL	#16, R15
+	SHLL	#16, R15 ; Shifted left as it is restored to the low order word.
 	PUSH.L	R15
 
 	/* Save the stack pointer to the TCB. */
@@ -293,7 +309,7 @@ static void prvYieldHandler( void )
 	/* Select the next task to run. */
 	BSR.A	_vTaskSwitchContext
 
-	/* Reset the interrupt mask. */
+	/* Reset the interrupt mask as no more data structure access is required. */
 	MVTIPL	#configKERNEL_INTERRUPT_PRIORITY
 
 	/* Load the stack pointer of the task that is now selected as the Running

Source/portable/Renesas/RX600/portmacro.h

@@ -92,19 +92,15 @@ portSTACK_TYPE and portBASE_TYPE. */
 /*-----------------------------------------------------------*/
 
 /* Hardware specifics. */
-#define portBYTE_ALIGNMENT				8
+#define portBYTE_ALIGNMENT				8	/* Could make four, according to manual. */
 #define portSTACK_GROWTH				-1
 #define portTICK_RATE_MS				( ( portTickType ) 1000 / configTICK_RATE_HZ )		
 #define portNOP()						nop()
-#define portSTART_SCHEDULER_TRAP_NO		( 32 )
-#define portKERNEL_INTERRUPT_PRIORITY	( 1 )
 
 /* The location of the software interrupt register.  Software interrupts use
 vector 27. */
 #define portITU_SWINTR			( ( unsigned char * ) 0x000872E0 )
 #define portYIELD()				*portITU_SWINTR = 0x01; nop(); nop(); nop(); nop(); nop()
-
-extern void vTaskSwitchContext( void );
 #define portYIELD_FROM_ISR( x )	if( x != pdFALSE ) portYIELD()
 
 /*
@@ -114,9 +110,6 @@ extern void vTaskSwitchContext( void );
 #define portENABLE_INTERRUPTS() 	set_ipl( 0 )
 #define portDISABLE_INTERRUPTS() 	set_ipl( configMAX_SYSCALL_INTERRUPT_PRIORITY )
 
-#define portSET_INTERRUPT_MASK_FROM_ISR() get_ipl(); set_ipl( configMAX_SYSCALL_INTERRUPT_PRIORITY )
-#define portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus ) set_ipl( uxSavedInterruptStatus )
-
 /* Critical nesting counts are stored in the TCB. */
 #define portCRITICAL_NESTING_IN_TCB ( 1 )
 
@@ -126,6 +119,9 @@ extern void vTaskExitCritical( void );
 #define portENTER_CRITICAL()	vTaskEnterCritical();
 #define portEXIT_CRITICAL()		vTaskExitCritical();
 
+/* As this port allows interrupt nesting... */
+#define portSET_INTERRUPT_MASK_FROM_ISR() get_ipl(); set_ipl( configMAX_SYSCALL_INTERRUPT_PRIORITY )
+#define portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus ) set_ipl( uxSavedInterruptStatus )
 
 /*-----------------------------------------------------------*/