Tidy up the MicoBlaze port layer - still a work in progress.

Demo/MicroBlaze_Spartan-6_EthernetLite/SDKProjects/RTOSDemoSource/FreeRTOS_Source/portable/GCC/MicroBlaze/port.c

@@ -77,13 +77,6 @@ to the scheduler being commenced we don't want the critical nesting level
 to reach zero, so it is initialised to a high value. */
 #define portINITIAL_NESTING_VALUE	( 0xff )
 
-/* Our hardware setup only uses one counter. */
-#define portCOUNTER_0 				0
-
-/* The stack used by the ISR is filled with a known value to assist in
-debugging. */
-#define portISR_STACK_FILL_VALUE	0x55555555
-
 /*-----------------------------------------------------------*/
 
 /*
@@ -231,26 +224,19 @@ const unsigned long ulR13 = ( unsigned long ) &_SDA_BASE_;
 
 portBASE_TYPE xPortStartScheduler( void )
 {
-extern void ( vStartFirstTask )( void );
+extern void ( vPortStartFirstTask )( void );
+extern unsigned long *_stack;
 
 	/* Setup the hardware to generate the tick.  Interrupts are disabled when
 	this function is called. */
 	vApplicationSetupTimerInterrupt();
 
 	/* Allocate the stack to be used by the interrupt handler. */
-	pulISRStack = ( unsigned long * ) pvPortMalloc( configINTERRUPT_STACK_SIZE * sizeof( portSTACK_TYPE ) );
+	pulISRStack = _stack;
-	configASSERT( pulISRStack != NULL );
 
-	/* Restore the context of the first task that is going to run. */
+	/* Restore the context of the first task that is going to run.  From here
-	if( pulISRStack != NULL )
+	on, the created tasks will be executing. */
-	{
+	vPortStartFirstTask();
-		/* Fill the ISR stack with a known value to facilitate debugging. */
-		memset( pulISRStack, portISR_STACK_FILL_VALUE, configMINIMAL_STACK_SIZE * sizeof( portSTACK_TYPE ) );
-		pulISRStack += ( configMINIMAL_STACK_SIZE - 1 );
-
-		/* From here on, the created tasks will be executing. */
-		vStartFirstTask();
-	}
 
 	/* Should not get here as the tasks are now running! */
 	return pdFALSE;

Demo/MicroBlaze_Spartan-6_EthernetLite/SDKProjects/RTOSDemoSource/FreeRTOS_Source/portable/GCC/MicroBlaze/portasm.s

@@ -63,19 +63,22 @@
 	.extern uxCriticalNesting
 	.extern pulISRStack
 
-/*	.global vPortFreeRTOSInterruptHandler */
 	.global _interrupt_handler
 	.global VPortYieldASM
-	.global vStartFirstTask
+	.global vPortStartFirstTask
 
 
 .macro portSAVE_CONTEXT
+
 	/* Make room for the context on the stack. */
 	addik r1, r1, -132
-	/* Save r31 so it can then be used. */
+
+	/* Save r31 so it can then be used as a temporary. */
 	swi r31, r1, 4
+
 	/* Copy the msr into r31 - this is stacked later. */
 	mfs r31, rmsr
+
 	/* Stack general registers. */
 	swi r30, r1, 12
 	swi r29, r1, 16
@@ -105,9 +108,11 @@
 	swi r4, r1, 116
 	swi r3, r1, 120
 	swi r2, r1, 124
+
 	/* Stack the critical section nesting value. */
 	lwi r3, r0, uxCriticalNesting
 	swi r3, r1, 128
+
 	/* Save the top of stack value to the TCB. */
 	lwi r3, r0, pxCurrentTCB
 	sw	r1, r0, r3
@@ -115,9 +120,11 @@
 	.endm
 
 .macro portRESTORE_CONTEXT
+
 	/* Load the top of stack value from the TCB. */
 	lwi r3, r0, pxCurrentTCB
 	lw	r1, r0, r3	
+
 	/* Restore the general registers. */
 	lwi r31, r1, 4		
 	lwi r30, r1, 12		
@@ -149,38 +156,30 @@
 	lwi r4, r1, 116
 	lwi r2, r1, 124
 
+	/* Reload the rmsr from the stack. */
+	lwi r3, r1, 8
+	mts rmsr, r3
+
 	/* Load the critical nesting value. */
 	lwi r3, r1, 128
 	swi r3, r0, uxCriticalNesting
 
-	/* Obtain the MSR value from the stack. */
+	/* Test the critical nesting value.  If it is non zero then the task last
-	lwi r3, r1, 8
+	exited the running state using a yield.  If it is zero, then the task
+	last exited the running state through an interrupt. */
+	xori r3, r3, 0
+	bnei r3, exit_from_yield
 
-	/* Are interrupts enabled in the MSR?  If so return using an return from 
+	/* r3 was being used as a temporary.  Now restore its true value from the
-	interrupt instruction to ensure interrupts are enabled only once the task
+	stack. */
-	is running again. */
-	andi r3, r3, 2
-	beqid r3, 36
-	or r0, r0, r0
-
-	/* Reload the rmsr from the stack, clear the enable interrupt bit in the
-	value before saving back to rmsr register, then return enabling interrupts
-	as we return. */
-	lwi r3, r1, 8
-	andi r3, r3, ~2
-	mts rmsr, r3
 	lwi r3, r1, 120
-	addik r1, r1, 132
-	rtid r14, 0
-	or r0, r0, r0
 
-	/* Reload the rmsr from the stack, place it in the rmsr register, and
+	/* Remove the stack frame. */
-	return without enabling interrupts. */
-	lwi r3, r1, 8
-	mts rmsr, r3
-	lwi r3, r1, 120
 	addik r1, r1, 132
-	rtsd r14, 0
+
+	/* Return using rtid so interrupts are re-enabled as this function is
+	exited. */
+	rtid r14, 0
 	or r0, r0, r0
 
 	.endm
@@ -188,41 +187,68 @@
 	.text
 	.align  2
 
+/* This function is used to exit portRESTORE_CONTEXT() if the task being
+returned to last left the Running state by calling taskYIELD() (rather than
+being preempted by an interrupt. */
+exit_from_yield:
+
+	/* r3 was being used as a temporary.  Now restore its true value from the
+	stack. */
+	lwi r3, r1, 120
+
+	/* Remove the stack frame. */
+	addik r1, r1, 132
+
+	/* Return to the task. */
+	rtsd r14, 0
+	or r0, r0, r0
+
 
-/*vPortFreeRTOSInterruptHandler:*/
 _interrupt_handler:
+
 	portSAVE_CONTEXT
-	/* Entered via an interrupt so interrupts must be enabled in msr. */
+
-	ori r31, r31, 2
 	/* Stack msr. */
 	swi r31, r1, 8
-	/* Stack the return address.  As we entered via an interrupt we do
+
-	not need to modify the return address prior to stacking. */
+	/* Stack the return address. */
 	swi r14, r1, 76
-	/* Now switch to use the ISR stack. */
+
-	lwi r3, r0, pulISRStack
+	/* Switch to the ISR stack. */
-	add r1, r3, r0
+	lwi r1, r0, pulISRStack
+
+	/* Execute any pending interrupts. */
 	bralid r15, XIntc_DeviceInterruptHandler
 	or r0, r0, r0
+
+	/* Restore the context of the next task scheduled to execute. */
 	portRESTORE_CONTEXT
 
 
 VPortYieldASM:
+
 	portSAVE_CONTEXT
+
 	/* Stack msr. */
 	swi r31, r1, 8
-	/* Modify the return address so we return to the instruction after the
+
-	exception. */
+	/* Modify the return address so a return is done to the instruction after
+	the call to VPortYieldASM. */
 	addi r14, r14, 8
 	swi r14, r1, 76
-	/* Now switch to use the ISR stack. */
+
-	lwi r3, r0, pulISRStack
+	/* Switch to use the ISR stack. */
-	add r1, r3, r0
+	lwi r1, r0, pulISRStack
+
+	/* Select the next task to execute. */
 	bralid r15, vTaskSwitchContext
 	or r0, r0, r0
+
+	/* Restore the context of the next task scheduled to execute. */
 	portRESTORE_CONTEXT
 
-vStartFirstTask:
+vPortStartFirstTask:
+
 	portRESTORE_CONTEXT
 	
 	

Demo/MicroBlaze_Spartan-6_EthernetLite/SDKProjects/RTOSDemoSource/main-blinky.c

@@ -428,7 +428,8 @@ void vApplicationSetupTimerInterrupt( void )
 {
 portBASE_TYPE xStatus;
 const unsigned char ucTimerCounterNumber = ( unsigned char ) 0U;
-const unsigned long ulCounterValue = ( ( XPAR_AXI_TIMER_0_CLOCK_FREQ_HZ / configTICK_RATE_HZ ) - 1UL );
+//const unsigned long ulCounterValue = ( ( XPAR_AXI_TIMER_0_CLOCK_FREQ_HZ / configTICK_RATE_HZ ) - 1UL );
+const unsigned long ulCounterValue = ( ( ( XPAR_AXI_TIMER_0_CLOCK_FREQ_HZ / configTICK_RATE_HZ ) - 1UL ) ) * 2UL; //_RB_ there is a clock set up incorrectly somwehre, the *2 should not be required. */
 extern void vTickISR( void *pvUnused );
 
 	/* Initialise the timer/counter. */
@@ -475,4 +476,17 @@ unsigned long ulCSR;
 	ulCSR = XTmrCtr_GetControlStatusReg( XPAR_AXI_TIMER_0_BASEADDR, 0 );
 	XTmrCtr_SetControlStatusReg( XPAR_AXI_TIMER_0_BASEADDR, 0, ulCSR );
 }
+/*-----------------------------------------------------------*/
+
+void vAssertCalled( char *pcFile, long lLine )
+{
+volatile unsigned long ul = 1;
 
+	taskDISABLE_INTERRUPTS();
+	while( ul == 1 )
+	{
+		/* Just for somewhere to put a breakpoint. */
+		portNOP();
+	}
+	taskENABLE_INTERRUPTS();
+}

Demo/MicroBlaze_Spartan-6_EthernetLite/SDKProjects/RTOSDemoSource/main-full.c

@@ -546,7 +546,7 @@ const unsigned char ucSetToOutput = 0U;
 }
 /*-----------------------------------------------------------*/
 
-extern void vAssertCalled( char *pcFile, long lLine )
+void vAssertCalled( char *pcFile, long lLine )
 {
 volatile unsigned long ul = 1;