GBA hardware extensions

.gitignore

@@ -6,6 +6,7 @@
 /build
 /build-*
 /.vs
+/.vscode
 
 *.a
 *.dylib

include/mgba/core/core.h

@@ -11,6 +11,7 @@
 CXX_GUARD_START
 
 #include <mgba/core/config.h>
+#include <mgba/core/serialize.h>
 #if !defined(MINIMAL_CORE) || MINIMAL_CORE < 2
 #include <mgba/core/directories.h>
 #endif
@@ -160,6 +161,9 @@ struct mCore {
 	void (*startVideoLog)(struct mCore*, struct mVideoLogContext*);
 	void (*endVideoLog)(struct mCore*);
 #endif
+
+	size_t (*extDataSerialize)(struct mCore*, enum mStateExtdataTag tag, void** sram);
+	bool (*extDataDeserialize)(struct mCore*, enum mStateExtdataTag tag, const void* sram, size_t size);
 };
 
 #if !defined(MINIMAL_CORE) || MINIMAL_CORE < 2

include/mgba/core/serialize.h

@@ -16,6 +16,7 @@ enum mStateExtdataTag {
 	EXTDATA_SAVEDATA = 2,
 	EXTDATA_CHEATS = 3,
 	EXTDATA_RTC = 4,
+	EXTDATA_GBA_EXTENSIONS = 0x80,
 	EXTDATA_META_TIME = 0x101,
 	EXTDATA_MAX
 };
@@ -25,6 +26,7 @@ enum mStateExtdataTag {
 #define SAVESTATE_CHEATS     4
 #define SAVESTATE_RTC        8
 #define SAVESTATE_METADATA   16
+#define SAVESTATE_GBA_EXTENSIONS   32
 
 struct mStateExtdataItem {
 	int32_t size;

include/mgba/internal/gba/extra/extensions.h

@@ -0,0 +1,70 @@
+/* Copyright (c) 2013-2021 Jeffrey Pfau
+ *
+ * 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/. */
+#ifndef GBA_EXTENSIONS_H
+#define GBA_EXTENSIONS_H
+
+#include <mgba-util/common.h>
+
+CXX_GUARD_START
+
+#include <mgba/core/log.h>
+#include <mgba/core/timing.h>
+
+#include <mgba/internal/gba/io.h>
+
+#include <mgba-util/memory.h>
+
+enum GBA_EXTENSIONS_IDS {
+	GBAEX_ID_EXTRA_RAM = 0,
+	GBAEX_EXTENSIONS_COUNT
+};
+
+#define REG_HWEX_VERSION_VALUE GBAEX_EXTENSIONS_COUNT
+#define GBAEX_IO_SIZE (REG_HWEX_END - REG_HWEX0_ENABLE)
+
+struct GBAExtensions {
+	bool globalEnabled;
+	bool extensionsEnabled[GBAEX_EXTENSIONS_COUNT];
+	bool userGlobalEnabled;
+	bool userExtensionsEnabled[GBAEX_EXTENSIONS_COUNT];
+
+	// IO:
+	uint16_t* io;
+
+	// Other data
+	uint8_t* extraRam;
+	uint32_t extraRamSize;
+	uint32_t extraRamRealSize;
+};
+
+struct GBAExtensionsStateBlockHeader {
+	uint32_t id;
+	uint32_t offset;
+	uint32_t size;
+};
+
+struct GBAExtensionsState {
+	uint32_t version;
+	uint32_t extensionsBlockCount;
+
+	struct GBAExtensionsStateBlockHeader ioBlockHeader;
+	// More blocks can come after the IO one
+};
+
+struct GBA;
+void GBAExtensionsInit(struct GBAExtensions* extensions);
+void GBAExtensionsReset(struct GBAExtensions* extensions);
+void GBAExtensionsDestroy(struct GBAExtensions* extensions);
+uint16_t GBAExtensionsIORead(struct GBA* gba, uint32_t address);
+uint32_t GBAExtensionsIORead32(struct GBA* gba, uint32_t address);
+void GBAExtensionsIOWrite8(struct GBA* gba, uint32_t address, uint8_t value);
+void GBAExtensionsIOWrite(struct GBA* gba, uint32_t address, uint16_t value);
+size_t GBAExtensionsSerialize(struct GBA* gba, void** sram);
+bool GBAExtensionsDeserialize(struct GBA* gba, const struct GBAExtensionsState* state, size_t size);
+
+CXX_GUARD_END
+
+#endif

include/mgba/internal/gba/gba.h

@@ -18,6 +18,7 @@ CXX_GUARD_START
 #include <mgba/internal/gba/audio.h>
 #include <mgba/internal/gba/sio.h>
 #include <mgba/internal/gba/timer.h>
+#include <mgba/internal/gba/extra/extensions.h>
 
 #define GBA_ARM7TDMI_FREQUENCY 0x1000000U
 
@@ -70,6 +71,7 @@ struct GBA {
 	struct GBAVideo video;
 	struct GBAAudio audio;
 	struct GBASIO sio;
+	struct GBAExtensions extensions;
 
 	struct mCoreSync* sync;
 	struct mTiming timing;

include/mgba/internal/gba/io.h

@@ -157,6 +157,27 @@ enum GBAIORegisters {
 	REG_DEBUG_STRING = 0xFFF600,
 	REG_DEBUG_FLAGS = 0xFFF700,
 	REG_DEBUG_ENABLE = 0xFFF780,
+
+	// Extensions
+	REG_HWEX_ENABLE = 0x400A00,
+	REG_HWEX_VERSION = 0x400A02,
+
+	// Extra RAM
+	REG_HWEX0_ENABLE = 0x400A04,
+	REG_HWEX0_CNT = 0x400A06,
+	REG_HWEX0_RET_CODE = 0x400A08,
+	REG_HWEX0_UNUSED = 0x400A0A,
+	REG_HWEX0_P0_LO = 0x400A0C,	// command
+	REG_HWEX0_P0_HI = 0x400A0E,
+	REG_HWEX0_P1_LO = 0x400A10,	// index
+	REG_HWEX0_P1_HI = 0x400A12,
+	REG_HWEX0_P2_LO = 0x400A14,	// data pointer
+	REG_HWEX0_P2_HI = 0x400A16,
+	REG_HWEX0_P3_LO = 0x400A18,	// size
+	REG_HWEX0_P3_HI = 0x400A1A,
+
+	REG_HWEX_END = 0x400A1C,
+
 };
 
 mLOG_DECLARE_CATEGORY(GBA_IO);

src/core/serialize.c

@@ -421,6 +421,18 @@ bool mCoreSaveStateNamed(struct mCore* core, struct VFile* vf, int flags) {
 			mStateExtdataPut(&extdata, EXTDATA_RTC, &item);
 		}
 	}
+	if ((true || flags & SAVESTATE_GBA_EXTENSIONS) && core->extDataSerialize) {
+		void* sram = NULL;
+		size_t size = core->extDataSerialize(core, EXTDATA_GBA_EXTENSIONS, &sram);
+		if (size) {
+			struct mStateExtdataItem item = {
+				.size = size,
+				.data = sram,
+				.clean = free
+			};
+			mStateExtdataPut(&extdata, EXTDATA_GBA_EXTENSIONS, &item);
+		}
+	}
 #ifdef USE_PNG
 	if (!(flags & SAVESTATE_SCREENSHOT)) {
 #else
@@ -537,6 +549,10 @@ bool mCoreLoadStateNamed(struct mCore* core, struct VFile* vf, int flags) {
 			core->rtc.d.deserialize(&core->rtc.d, &item);
 		}
 	}
+	if ((true || flags & SAVESTATE_GBA_EXTENSIONS) && core->extDataDeserialize && mStateExtdataGet(&extdata, EXTDATA_GBA_EXTENSIONS, &item)) {
+		mLOG(SAVESTATE, INFO, "Loading GBA extensions");
+		core->extDataDeserialize(core, EXTDATA_GBA_EXTENSIONS, item.data, item.size);
+	}
 	mStateExtdataDeinit(&extdata);
 	return success;
 }

src/feature/commandline.c

@@ -248,6 +248,15 @@ void usage(const char* arg0, const char* extraOptions) {
 	puts("  -p, --patch FILE           Apply a specified patch file when running");
 	puts("  -s, --frameskip N          Skip every N frames");
 	puts("  --version                  Print version and exit");
+
+	puts("\nHardware extensions options:");
+	puts("  --hw-extensions            Enable hardware extensions");
+	puts("  --no-hw-extensions         Disable hardware extensions");
+	puts("  --hwex-all                 Enable all hardware extensions");
+	puts("  --hwex-none                Disable all hardware extensions");
+	puts("  --hwex-more-ram            Enable hardware extension \"More RAM\"");
+	puts("  --no-hwex-more-ram         Disable hardware extension \"More RAM\"");
+
 	if (extraOptions) {
 		puts(extraOptions);
 	}

src/gb/core.c

@@ -1141,6 +1141,8 @@ struct mCore* GBCoreCreate(void) {
 	core->startVideoLog = _GBCoreStartVideoLog;
 	core->endVideoLog = _GBCoreEndVideoLog;
 #endif
+	core->extDataSerialize = NULL;
+	core->extDataDeserialize = NULL;
 	return core;
 }
 

src/gba/CMakeLists.txt

@@ -13,6 +13,7 @@ set(SOURCE_FILES
 	cheats/parv3.c
 	core.c
 	dma.c
+	extra/extensions.c
 	gba.c
 	hle-bios.c
 	input.c

src/gba/core.c

@@ -307,6 +307,13 @@ static void _GBACoreLoadConfig(struct mCore* core, const struct mCoreConfig* con
 #endif
 	mCoreConfigCopyValue(&core->config, config, "hwaccelVideo");
 	mCoreConfigCopyValue(&core->config, config, "videoScale");
+
+	if (mCoreConfigGetIntValue(config, "gba.extensions", &fakeBool)) {
+		gba->extensions.userGlobalEnabled = fakeBool;
+	}
+	if (mCoreConfigGetIntValue(config, "gba.ext.extraRam", &fakeBool)) {
+		gba->extensions.userExtensionsEnabled[GBAEX_ID_EXTRA_RAM] = fakeBool;
+	}
 }
 
 static void _GBACoreReloadConfigOption(struct mCore* core, const char* option, const struct mCoreConfig* config) {
@@ -399,6 +406,19 @@ static void _GBACoreReloadConfigOption(struct mCore* core, const char* option, c
 			GBAVideoAssociateRenderer(&gba->video, renderer);
 		}
 	}
+
+	if (strcmp("gba.extensions", option) == 0) {
+		if (mCoreConfigGetIntValue(config, "gba.extensions", &fakeBool)) {
+			gba->extensions.userGlobalEnabled = fakeBool;
+		}
+		return;
+	}
+	if (strcmp("gba.ext.extraRam", option) == 0) {
+		if (mCoreConfigGetIntValue(config, "gba.ext.extraRam", &fakeBool)) {
+			gba->extensions.userExtensionsEnabled[GBAEX_ID_EXTRA_RAM] = fakeBool;
+		}
+		return;
+	}
 }
 
 static void _GBACoreDesiredVideoDimensions(const struct mCore* core, unsigned* width, unsigned* height) {
@@ -1152,6 +1172,25 @@ static void _GBACoreEndVideoLog(struct mCore* core) {
 }
 #endif
 
+static size_t _GBAExtDataSerialize(struct mCore* core, enum mStateExtdataTag tag, void** sram) {
+	size_t size;
+	if (tag == EXTDATA_GBA_EXTENSIONS) {
+		return GBAExtensionsSerialize(core->board, sram);
+	} else {
+		size = 0;
+		*sram = NULL;
+	}
+
+	return size;
+}
+
+static bool _GBAExtDataDeserialize(struct mCore* core, enum mStateExtdataTag tag, const void* sram, size_t size) {
+	if (tag == EXTDATA_GBA_EXTENSIONS) {
+		return GBAExtensionsDeserialize(core->board, sram, size);
+	}
+	return false;
+}
+
 struct mCore* GBACoreCreate(void) {
 	struct GBACore* gbacore = malloc(sizeof(*gbacore));
 	struct mCore* core = &gbacore->d;
@@ -1236,6 +1275,8 @@ struct mCore* GBACoreCreate(void) {
 	core->startVideoLog = _GBACoreStartVideoLog;
 	core->endVideoLog = _GBACoreEndVideoLog;
 #endif
+	core->extDataSerialize = _GBAExtDataSerialize;
+	core->extDataDeserialize = _GBAExtDataDeserialize;
 	return core;
 }