[nostalgia/core/gba] Add IRQ system

src/nostalgia/core/CMakeLists.txt

@@ -1,6 +1,5 @@
 add_library(
 	NostalgiaCore
-		core.cpp
 		gfx.cpp
 		media.cpp
 )

src/nostalgia/core/gba/CMakeLists.txt

@@ -3,10 +3,14 @@ if(NOSTALGIA_BUILD_TYPE STREQUAL "GBA")
 		NostalgiaCore-GBA
 			core.cpp
 			gfx.cpp
+			irq.arm.cpp
+			irq.cpp
 			media.cpp
 			panic.cpp
 	)
 
+	set_source_files_properties(irq.arm.cpp PROPERTIES COMPILE_FLAGS -marm)
+
 	target_link_libraries(
 		NostalgiaCore-GBA PUBLIC
 			NostalgiaCore

src/nostalgia/core/gba/addresses.hpp

@@ -1,18 +1,30 @@
 /*
- * Copyright 2016 - 2019 gtalent2@gmail.com
+ * Copyright 2016 - 2020 gtalent2@gmail.com
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
+
 #pragma once
 
 #include <ox/std/types.hpp>
 
 /////////////////////////////////////////////////////////////////
-// I/O Registers
+// Interrupt Handler
 
-#define REG_DISPCNT *reinterpret_cast<volatile uint32_t*>(0x04000000)
+using interrupt_handler = void (*)(void);
+#define REG_ISR *reinterpret_cast<interrupt_handler*>(0x03007FFC)
+#define REG_IE  *reinterpret_cast<volatile uint16_t*>(0x04000200)
+#define REG_IF  *reinterpret_cast<volatile uint16_t*>(0x04000202)
+#define REG_IME *reinterpret_cast<volatile uint16_t*>(0x04000208)
+
+/////////////////////////////////////////////////////////////////
+// Display Registers
+
+#define REG_DISPCNT  *reinterpret_cast<volatile uint32_t*>(0x04000000)
+#define REG_DISPSTAT *reinterpret_cast<volatile uint32_t*>(0x04000004)
+#define REG_VCOUNT   *reinterpret_cast<volatile uint32_t*>(0x04000006)
 
 /////////////////////////////////////////////////////////////////
 // background registers
@@ -35,7 +47,6 @@
 #define REG_BG2VOFS *reinterpret_cast<volatile uint32_t*>(0x0400001a)
 #define REG_BG3VOFS *reinterpret_cast<volatile uint32_t*>(0x0400001e)
 
-
 /////////////////////////////////////////////////////////////////
 // Memory Addresses
 

src/nostalgia/core/gba/core.cpp

@@ -8,8 +8,16 @@
 
 #include <nostalgia/core/core.hpp>
 
+#include "irq.hpp"
+
 namespace nostalgia::core {
 
+ox::Error init(Context *ctx) {
+	oxReturnError(initGfx(ctx));
+	oxReturnError(initIrq(ctx));
+	return OxError(0);
+}
+
 ox::Error run(Context*) {
 	while (1) {
 	}

src/nostalgia/core/gba/irq.arm.cpp

@@ -1,18 +1,20 @@
 /*
- * Copyright 2016 - 2019 gtalent2@gmail.com
+ * Copyright 2016 - 2020 gtalent2@gmail.com
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-#include "mem.hpp"
+// NOTE: this file is compiled as ARM and not THUMB, so don't but too much in
-#include "core.hpp"
+// here
+
+#include "irq.hpp"
 
 namespace nostalgia::core {
 
-ox::Error init(Context *ctx) {
+void isr() {
-	return initGfx(ctx);
+	REG_IF = IntId_vblank;
 }
 
 }

src/nostalgia/core/gba/irq.cpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2016 - 2020 gtalent2@gmail.com
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include "irq.hpp"
+
+namespace nostalgia::core {
+
+constexpr auto DispStat_irq_vblank = static_cast<uint16_t>(1) << 3;
+constexpr auto DispStat_irq_hblank = static_cast<uint16_t>(1) << 4;
+constexpr auto DispStat_irq_vcount = static_cast<uint16_t>(1) << 5;
+
+void isr();
+
+ox::Error initIrq(Context*) {
+	REG_ISR = isr;
+	// tell display to trigger vblank interrupts
+	REG_DISPSTAT |= DispStat_irq_vblank;
+	// tell proc which interrupts to handle
+	REG_IE |= IntId_vblank;
+	REG_IME = 1;
+	return OxError(0);
+}
+
+}

src/nostalgia/core/gba/irq.hpp

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2016 - 2020 gtalent2@gmail.com
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <nostalgia/core/context.hpp>
+
+#include "addresses.hpp"
+
+namespace nostalgia::core {
+
+constexpr uint16_t IntId_vblank = static_cast<uint64_t>(1) << 0;
+constexpr uint16_t IntId_hblank = static_cast<uint64_t>(1) << 1;
+constexpr uint16_t IntId_vcount = static_cast<uint64_t>(1) << 2;
+constexpr uint16_t IntId_timer0 = static_cast<uint64_t>(1) << 3;
+constexpr uint16_t IntId_timer1 = static_cast<uint64_t>(1) << 4;
+constexpr uint16_t IntId_timer2 = static_cast<uint64_t>(1) << 5;
+constexpr uint16_t IntId_serial = static_cast<uint64_t>(1) << 6;  // link cable
+constexpr uint16_t IntId_input  = static_cast<uint64_t>(1) << 14; // gamepad
+constexpr uint16_t IntId_cart   = static_cast<uint64_t>(1) << 15; // cartridge removed
+
+[[nodiscard]] ox::Error initIrq(Context *ctx);
+
+}

src/nostalgia/core/sdl/core.cpp

@@ -8,12 +8,17 @@
 
 #include <SDL.h>
 
-#include <nostalgia/core/core.hpp>
+#include <nostalgia/core/gfx.hpp>
 
 namespace nostalgia::core {
 
 void draw(Context *ctx);
 
+ox::Error init(Context *ctx) {
+	oxReturnError(initGfx(ctx));
+	return OxError(0);
+}
+
 ox::Error run(Context *ctx) {
 	for (auto running = true; running;) {
 		SDL_Event event;