From 383e7ae14a01301899e183432fda22bb8e82a61e Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Sun, 5 Mar 2023 22:37:56 +0100
Subject: [PATCH] machine, runtime/interrupt: switch to use register
 definitions from device/gba

Signed-off-by: deadprogram <ron@hybridgroup.com>
---
 src/machine/machine_gameboyadvance.go         | 42 ++++-----
 .../interrupt/interrupt_gameboyadvance.go     | 94 +++++++------------
 2 files changed, 55 insertions(+), 81 deletions(-)

diff --git a/src/machine/machine_gameboyadvance.go b/src/machine/machine_gameboyadvance.go
index 0c4cd7cb..0b666a4b 100644
--- a/src/machine/machine_gameboyadvance.go
+++ b/src/machine/machine_gameboyadvance.go
@@ -3,8 +3,9 @@
 package machine
 
 import (
+	"device/gba"
+
 	"image/color"
-	"runtime/interrupt"
 	"runtime/volatile"
 	"unsafe"
 )
@@ -16,40 +17,37 @@ const deviceName = "GBA"
 // Interrupt numbers as used on the GameBoy Advance. Register them with
 // runtime/interrupt.New.
 const (
-	IRQ_VBLANK  = interrupt.IRQ_VBLANK
-	IRQ_HBLANK  = interrupt.IRQ_HBLANK
-	IRQ_VCOUNT  = interrupt.IRQ_VCOUNT
-	IRQ_TIMER0  = interrupt.IRQ_TIMER0
-	IRQ_TIMER1  = interrupt.IRQ_TIMER1
-	IRQ_TIMER2  = interrupt.IRQ_TIMER2
-	IRQ_TIMER3  = interrupt.IRQ_TIMER3
-	IRQ_COM     = interrupt.IRQ_COM
-	IRQ_DMA0    = interrupt.IRQ_DMA0
-	IRQ_DMA1    = interrupt.IRQ_DMA1
-	IRQ_DMA2    = interrupt.IRQ_DMA2
-	IRQ_DMA3    = interrupt.IRQ_DMA3
-	IRQ_KEYPAD  = interrupt.IRQ_KEYPAD
-	IRQ_GAMEPAK = interrupt.IRQ_GAMEPAK
+	IRQ_VBLANK  = gba.IRQ_VBLANK
+	IRQ_HBLANK  = gba.IRQ_HBLANK
+	IRQ_VCOUNT  = gba.IRQ_VCOUNT
+	IRQ_TIMER0  = gba.IRQ_TIMER0
+	IRQ_TIMER1  = gba.IRQ_TIMER1
+	IRQ_TIMER2  = gba.IRQ_TIMER2
+	IRQ_TIMER3  = gba.IRQ_TIMER3
+	IRQ_COM     = gba.IRQ_COM
+	IRQ_DMA0    = gba.IRQ_DMA0
+	IRQ_DMA1    = gba.IRQ_DMA1
+	IRQ_DMA2    = gba.IRQ_DMA2
+	IRQ_DMA3    = gba.IRQ_DMA3
+	IRQ_KEYPAD  = gba.IRQ_KEYPAD
+	IRQ_GAMEPAK = gba.IRQ_GAMEPAK
 )
 
-// Make it easier to directly write to I/O RAM.
-var ioram = (*[0x400]volatile.Register8)(unsafe.Pointer(uintptr(0x04000000)))
-
 // Set has not been implemented.
 func (p Pin) Set(value bool) {
 	// do nothing
 }
 
-var Display = FramebufDisplay{(*[160][240]volatile.Register16)(unsafe.Pointer(uintptr(0x06000000)))}
+var Display = FramebufDisplay{(*[160][240]volatile.Register16)(unsafe.Pointer(uintptr(gba.MEM_VRAM)))}
 
 type FramebufDisplay struct {
 	port *[160][240]volatile.Register16
 }
 
 func (d FramebufDisplay) Configure() {
-	// Write into the I/O registers, setting video display parameters.
-	ioram[0].Set(0x03) // Use video mode 3 (in BG2, a 16bpp bitmap in VRAM)
-	ioram[1].Set(0x04) // Enable BG2 (BG0 = 1, BG1 = 2, BG2 = 4, ...)
+	// Use video mode 3 (in BG2, a 16bpp bitmap in VRAM) and Enable BG2
+	gba.DISP.DISPCNT.Set(gba.DISPCNT_BGMODE_3<<gba.DISPCNT_BGMODE_Pos |
+		gba.DISPCNT_SCREENDISPLAY_BG2_ENABLE<<gba.DISPCNT_SCREENDISPLAY_BG2_Pos)
 }
 
 func (d FramebufDisplay) Size() (x, y int16) {
diff --git a/src/runtime/interrupt/interrupt_gameboyadvance.go b/src/runtime/interrupt/interrupt_gameboyadvance.go
index b14f8059..13f5fbe0 100644
--- a/src/runtime/interrupt/interrupt_gameboyadvance.go
+++ b/src/runtime/interrupt/interrupt_gameboyadvance.go
@@ -5,37 +5,13 @@ package interrupt
 // This is good documentation of the GBA: https://www.akkit.org/info/gbatek.htm
 
 import (
-	"runtime/volatile"
-	"unsafe"
-)
-
-const (
-	IRQ_VBLANK  = 0
-	IRQ_HBLANK  = 1
-	IRQ_VCOUNT  = 2
-	IRQ_TIMER0  = 3
-	IRQ_TIMER1  = 4
-	IRQ_TIMER2  = 5
-	IRQ_TIMER3  = 6
-	IRQ_COM     = 7
-	IRQ_DMA0    = 8
-	IRQ_DMA1    = 9
-	IRQ_DMA2    = 10
-	IRQ_DMA3    = 11
-	IRQ_KEYPAD  = 12
-	IRQ_GAMEPAK = 13
-)
-
-var (
-	regInterruptEnable       = (*volatile.Register16)(unsafe.Pointer(uintptr(0x4000200)))
-	regInterruptRequestFlags = (*volatile.Register16)(unsafe.Pointer(uintptr(0x4000202)))
-	regGlobalInterruptEnable = (*volatile.Register16)(unsafe.Pointer(uintptr(0x4000208)))
+	"device/gba"
 )
 
 // Enable enables this interrupt. Right after calling this function, the
 // interrupt may be invoked if it was already pending.
 func (irq Interrupt) Enable() {
-	regInterruptEnable.SetBits(1 << uint(irq.num))
+	gba.INTERRUPT.IE.SetBits(1 << uint(irq.num))
 }
 
 var inInterrupt bool
@@ -43,10 +19,10 @@ var inInterrupt bool
 //export handleInterrupt
 func handleInterrupt() {
 	inInterrupt = true
-	flags := regInterruptRequestFlags.Get()
+	flags := gba.INTERRUPT.IF.Get()
 	for i := 0; i < 14; i++ {
 		if flags&(1<<uint(i)) != 0 {
-			regInterruptRequestFlags.Set(1 << uint(i)) // acknowledge interrupt
+			gba.INTERRUPT.IF.Set(1 << uint(i)) // acknowledge interrupt
 			callInterruptHandler(i)
 		}
 	}
@@ -62,34 +38,34 @@ func callHandlers(num int)
 
 func callInterruptHandler(id int) {
 	switch id {
-	case IRQ_VBLANK:
-		callHandlers(IRQ_VBLANK)
-	case IRQ_HBLANK:
-		callHandlers(IRQ_HBLANK)
-	case IRQ_VCOUNT:
-		callHandlers(IRQ_VCOUNT)
-	case IRQ_TIMER0:
-		callHandlers(IRQ_TIMER0)
-	case IRQ_TIMER1:
-		callHandlers(IRQ_TIMER1)
-	case IRQ_TIMER2:
-		callHandlers(IRQ_TIMER2)
-	case IRQ_TIMER3:
-		callHandlers(IRQ_TIMER3)
-	case IRQ_COM:
-		callHandlers(IRQ_COM)
-	case IRQ_DMA0:
-		callHandlers(IRQ_DMA0)
-	case IRQ_DMA1:
-		callHandlers(IRQ_DMA1)
-	case IRQ_DMA2:
-		callHandlers(IRQ_DMA2)
-	case IRQ_DMA3:
-		callHandlers(IRQ_DMA3)
-	case IRQ_KEYPAD:
-		callHandlers(IRQ_KEYPAD)
-	case IRQ_GAMEPAK:
-		callHandlers(IRQ_GAMEPAK)
+	case gba.IRQ_VBLANK:
+		callHandlers(gba.IRQ_VBLANK)
+	case gba.IRQ_HBLANK:
+		callHandlers(gba.IRQ_HBLANK)
+	case gba.IRQ_VCOUNT:
+		callHandlers(gba.IRQ_VCOUNT)
+	case gba.IRQ_TIMER0:
+		callHandlers(gba.IRQ_TIMER0)
+	case gba.IRQ_TIMER1:
+		callHandlers(gba.IRQ_TIMER1)
+	case gba.IRQ_TIMER2:
+		callHandlers(gba.IRQ_TIMER2)
+	case gba.IRQ_TIMER3:
+		callHandlers(gba.IRQ_TIMER3)
+	case gba.IRQ_COM:
+		callHandlers(gba.IRQ_COM)
+	case gba.IRQ_DMA0:
+		callHandlers(gba.IRQ_DMA0)
+	case gba.IRQ_DMA1:
+		callHandlers(gba.IRQ_DMA1)
+	case gba.IRQ_DMA2:
+		callHandlers(gba.IRQ_DMA2)
+	case gba.IRQ_DMA3:
+		callHandlers(gba.IRQ_DMA3)
+	case gba.IRQ_KEYPAD:
+		callHandlers(gba.IRQ_KEYPAD)
+	case gba.IRQ_GAMEPAK:
+		callHandlers(gba.IRQ_GAMEPAK)
 	}
 }
 
@@ -107,9 +83,9 @@ type State uint8
 // as you called Disable (this happens naturally with the pattern above).
 func Disable() (state State) {
 	// Save the previous interrupt state.
-	state = State(regGlobalInterruptEnable.Get())
+	state = State(gba.INTERRUPT.PAUSE.Get())
 	// Disable all interrupts.
-	regGlobalInterruptEnable.Set(0)
+	gba.INTERRUPT.PAUSE.Set(0)
 	return
 }
 
@@ -119,7 +95,7 @@ func Disable() (state State) {
 // cricital sections.
 func Restore(state State) {
 	// Restore interrupts to the previous state.
-	regGlobalInterruptEnable.Set(uint16(state))
+	gba.INTERRUPT.PAUSE.Set(uint16(state))
 }
 
 // In returns whether the system is currently in an interrupt.