work on interrupts

src/interrupts.s

@@ -44,7 +44,6 @@ internal_stack_pointer:
 
 ; -----------------------------------------------------------------------------
 ; Initialize the interrupt handler vectors.
-	.extern __program_start
 interrupts_init:
 	long_a
 	sei
@@ -109,6 +108,7 @@ interrupts_init:
 	sta long:0x00FF80
 
 	; Reset vector
+	.extern __program_start
 	lda ##.near(__program_start)
 	sta long:0x00FFFC
 
@@ -118,14 +118,6 @@ interrupts_init:
 
 	rts
 
-; -----------------------------------------------------------------------------
-; Null interrupt handler
-;
-; This handler intentionally does nothing. It is used to populate interrupt
-; vectors that do nothing, without wasting space on multiple such functions.
-null_handler:
-	rti
-
 ; -----------------------------------------------------------------------------
 ; The COP handler is the primary interface to the kernel from user code. The
 ; user program loads the function number into X, and any appropriate arguments
@@ -159,6 +151,13 @@ cop_handler_native:
 	jsr (.kbank cop_jump_table,x)
 
 	plb
+
+; -----------------------------------------------------------------------------
+; Null interrupt handler
+;
+; This handler intentionally does nothing. It is used to populate interrupt
+; vectors that do nothing, without wasting space on multiple such functions.
+null_handler:
 	rti
 
 cop_jump_table: