Fix: Interrut Handler Register Function and Exception Process (#41)

Signed-off-by: shiode <shiode@aptpod.co.jp>

Co-authored-by: Cobus van Eeden <35851496+cobusve@users.noreply.github.com>
Co-authored-by: David Chalco <59750547+dachalco@users.noreply.github.com>
Co-authored-by: Joseph Julicher <jjulicher@mac.com>

portable/GCC/NiosII/port.c

@@ -36,6 +36,7 @@
 
 /* Altera includes. */
 #include "sys/alt_irq.h"
+#include "sys/alt_exceptions.h"
 #include "altera_avalon_timer_regs.h"
 #include "priv/alt_irq_table.h"
 
@@ -46,6 +47,8 @@
 /* Interrupts are enabled. */
 #define portINITIAL_ESTATUS     ( StackType_t ) 0x01 
 
+int _alt_ic_isr_register(alt_u32 ic_id, alt_u32 irq, alt_isr_func isr,
+  void *isr_context, void *flags);
 /*-----------------------------------------------------------*/
 
 /* 
@@ -56,7 +59,7 @@ static void prvSetupTimerInterrupt( void );
 /*
  * Call back for the alarm function.
  */
-void vPortSysTickHandler( void * context, alt_u32 id );
+void vPortSysTickHandler( void * context);
 
 /*-----------------------------------------------------------*/
 
@@ -137,7 +140,7 @@ void vPortEndScheduler( void )
 void prvSetupTimerInterrupt( void )
 {
 	/* Try to register the interrupt handler. */
-	if ( -EINVAL == alt_irq_register( SYS_CLK_IRQ, 0x0, vPortSysTickHandler ) )
+	if ( -EINVAL == _alt_ic_isr_register( SYS_CLK_IRQ_INTERRUPT_CONTROLLER_ID, SYS_CLK_IRQ, vPortSysTickHandler, 0x0, 0x0 ) )
 	{ 
 		/* Failed to install the Interrupt Handler. */
 		asm( "break" );
@@ -156,7 +159,7 @@ void prvSetupTimerInterrupt( void )
 }
 /*-----------------------------------------------------------*/
 
-void vPortSysTickHandler( void * context, alt_u32 id )
+void vPortSysTickHandler( void * context)
 {
 	/* Increment the kernel tick. */
 	if( xTaskIncrementTick() != pdFALSE )
@@ -175,25 +178,27 @@ void vPortSysTickHandler( void * context, alt_u32 id )
  * kernel has its scheduler started so that contexts are saved and switched 
  * correctly.
  */
-int alt_irq_register( alt_u32 id, void* context, void (*handler)(void*, alt_u32) )
+int _alt_ic_isr_register(alt_u32 ic_id, alt_u32 irq, alt_isr_func isr,
+  void *isr_context, void *flags)
 {
 	int rc = -EINVAL;  
 	alt_irq_context status;
+	int id = irq;             /* IRQ interpreted as the interrupt ID. */
 
 	if (id < ALT_NIRQ)
 	{
 		/* 
 		 * interrupts are disabled while the handler tables are updated to ensure
-		 * that an interrupt doesn't occur while the tables are in an inconsistent
+		 * that an interrupt doesn't occur while the tables are in an inconsistant
 		 * state.
 		 */
 	
 		status = alt_irq_disable_all ();
 	
-		alt_irq[id].handler = handler;
-		alt_irq[id].context = context;
+		alt_irq[id].handler = isr;
+		alt_irq[id].context = isr_context;
 	
-		rc = (handler) ? alt_irq_enable (id): alt_irq_disable (id);
+		rc = (isr) ? alt_ic_irq_enable(ic_id, id) : alt_ic_irq_disable(ic_id, id);
 	
 		/* alt_irq_enable_all(status); This line is removed to prevent the interrupt from being immediately enabled. */
 	}

portable/GCC/NiosII/port_asm.S

@@ -34,11 +34,10 @@
 .globl restore_sp_from_pxCurrentTCB		
 	
 # Entry point for exceptions.
-.section .exceptions.entry, "xa"		
+.section .exceptions.entry.user, "xa"
 
 # Save the entire context of a task.
 save_context:
-	addi	ea, ea, -4			# Point to the next instruction.
 	addi	sp,	sp, -116		# Create space on the stack.
 	stw		ra, 0(sp)
 								# Leave a gap for muldiv 0
@@ -59,7 +58,8 @@ save_context:
 	stw		r15, 64(sp)
 	rdctl	r5, estatus 		# Save the eStatus
 	stw		r5, 68(sp)
-	stw		ea, 72(sp)			# Save the PC
+	addi	r15, ea, -4			# Instruction that caused exception
+	stw		r15, 72(sp)			# Save as EA
 	stw		r16, 76(sp)			# Save the remaining registers
 	stw		r17, 80(sp)
 	stw		r18, 84(sp)
@@ -75,24 +75,13 @@ save_sp_to_pxCurrentTCB:
 	movia	et, pxCurrentTCB	# Load the address of the pxCurrentTCB pointer
 	ldw		et, (et)			# Load the value of the pxCurrentTCB pointer
 	stw		sp, (et)			# Store the stack pointer into the top of the TCB
-	
-	.section .exceptions.irqtest, "xa"	
-hw_irq_test:
-	/*
-     * Test to see if the exception was a software exception or caused 
-     * by an external interrupt, and vector accordingly.
-     */
-    rdctl	r4, ipending		# Load the Pending Interrupts indication
-	rdctl	r5, estatus 		# Load the eStatus (enabled interrupts).
-    andi	r2, r5, 1			# Are interrupts enabled globally.
-    beq		r2, zero, soft_exceptions		# Interrupts are not enabled.
-    beq		r4, zero, soft_exceptions		# There are no interrupts triggered.
 
-	.section .exceptions.irqhandler, "xa"
-hw_irq_handler:
-	call	alt_irq_handler					# Call the alt_irq_handler to deliver to the registered interrupt handler.
+	br		irq_test_user					# skip the section .exceptions.entry
 
-    .section .exceptions.irqreturn, "xa"
+    .section .exceptions.irqtest, "xa"
+irq_test_user:
+
+    .section .exceptions.exit.user, "xa"
 restore_sp_from_pxCurrentTCB:
 	movia	et, pxCurrentTCB		# Load the address of the pxCurrentTCB pointer
 	ldw		et, (et)				# Load the value of the pxCurrentTCB pointer
@@ -135,16 +124,16 @@ restore_context:
    
 	.section .exceptions.soft, "xa"
 soft_exceptions:
-	ldw		et, 0(ea)				# Load the instruction where the interrupt occured.
-	movhi	at, %hi(0x003B683A)		# Load the registers with the trap instruction code
-	ori		at, at, %lo(0x003B683A)
-   	cmpne	et, et, at				# Compare the trap instruction code to the last excuted instruction
-  	beq		et, r0, call_scheduler	# its a trap so switchcontext
-  	break							# This is an un-implemented instruction or muldiv problem.
-  	br		restore_context			# its something else
+	movhi	r3, 0x003b				/* upper half of trap opcode */
+	ori		r3, r3, 0x683a			/* lower half of trap opcode */
+	beq		r2, r3, call_scheduler
+	br		exceptions_unknown_user			# its something else
 
 call_scheduler:
-	addi	ea, ea, 4						# A trap was called, increment the program counter so it is not called again.
-	stw		ea, 72(sp)						# Save the new program counter to the context.
+	stw		ea, 72(sp)						# EA is PC+4 so will skip over instruction causing exception
 	call	vTaskSwitchContext				# Pick the next context.
 	br		restore_sp_from_pxCurrentTCB	# Switch in the task context and restore. 
+
+	.section .exceptions.unknown.user
+exceptions_unknown_user:
+