From a7dbbbe578606a5d35d043d81512ef21827dff35 Mon Sep 17 00:00:00 2001
From: Colton Pawielski <cepawiel@users.noreply.github.com>
Date: Fri, 22 Sep 2023 02:10:44 -0700
Subject: [PATCH] Add Dreamcast 32MB RAM Mod (#1198)

---
 core/cfg/option.cpp                    |  1 +
 core/cfg/option.h                      |  1 +
 core/emulator.cpp                      |  2 +-
 core/rend/gui.cpp                      |  5 +++++
 core/serialize.h                       | 14 +++++++++++++-
 shell/libretro/libretro_core_options.h | 14 ++++++++++++++
 shell/libretro/option.cpp              |  1 +
 tests/src/serialize_test.cpp           |  2 +-
 8 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/core/cfg/option.cpp b/core/cfg/option.cpp
index 5d3e40028e..095f97f487 100644
--- a/core/cfg/option.cpp
+++ b/core/cfg/option.cpp
@@ -121,6 +121,7 @@ Option<int> GDBPort("Debug.GDBPort", debugger::DEFAULT_PORT);
 Option<bool> GDBWaitForConnection("Debug.GDBWaitForConnection");
 Option<bool> UseReios("UseReios");
 Option<bool> FastGDRomLoad("FastGDRomLoad", false);
+Option<bool> RamMod32MB("Dreamcast.RamMod32MB", false);
 
 Option<bool> OpenGlChecks("OpenGlChecks", false, "validate");
 
diff --git a/core/cfg/option.h b/core/cfg/option.h
index a4d784894b..5a14874864 100644
--- a/core/cfg/option.h
+++ b/core/cfg/option.h
@@ -480,6 +480,7 @@ extern Option<int> GDBPort;
 extern Option<bool> GDBWaitForConnection;
 extern Option<bool> UseReios;
 extern Option<bool> FastGDRomLoad;
+extern Option<bool> RamMod32MB;
 
 extern Option<bool> OpenGlChecks;
 
diff --git a/core/emulator.cpp b/core/emulator.cpp
index 0aefb9d84c..cbbc0f65a1 100644
--- a/core/emulator.cpp
+++ b/core/emulator.cpp
@@ -420,7 +420,7 @@ static void setPlatform(int platform)
 	switch (platform)
 	{
 	case DC_PLATFORM_DREAMCAST:
-		settings.platform.ram_size = 16_MB;
+		settings.platform.ram_size = config::RamMod32MB ? 32_MB : 16_MB;
 		settings.platform.vram_size = 8_MB;
 		settings.platform.aram_size = 2_MB;
 		settings.platform.bios_size = 2_MB;
diff --git a/core/rend/gui.cpp b/core/rend/gui.cpp
index f12aeb6ee5..4be8d0bcf2 100644
--- a/core/rend/gui.cpp
+++ b/core/rend/gui.cpp
@@ -2423,6 +2423,11 @@ static void gui_display_settings()
 	            OptionCheckbox("Serial Console", config::SerialConsole,
 	            		"Dump the Dreamcast serial console to stdout");
 #endif
+				{
+					DisabledScope scope(game_started);
+					OptionCheckbox("Dreamcast 32MB RAM Mod", config::RamMod32MB,
+						"Enables 32MB RAM Mod for Dreamcast. May affect compatibility");
+				}
 	            OptionCheckbox("Dump Textures", config::DumpTextures,
 	            		"Dump all textures into data/texdump/<game id>");
 
diff --git a/core/serialize.h b/core/serialize.h
index 795a9693f2..f364630bef 100644
--- a/core/serialize.h
+++ b/core/serialize.h
@@ -67,7 +67,8 @@ class SerializeBase
 		V39,
 		V40,
 		V41,
-		Current = V41,
+		V42,
+		Current = V42,
 
 		Next = Current + 1,
 	};
@@ -101,6 +102,15 @@ class Deserializer : public SerializeBase
 			throw Exception("Unsupported version");
 		if (_version > Current)
 			throw Exception("Version too recent");
+
+		if(_version >= V42 && settings.platform.isConsole())
+		{
+			u32 ramSize;
+			deserialize(ramSize);
+			if (ramSize != settings.platform.ram_size) {
+				throw Exception("Selected RAM Size doesn't match Save State");
+		}
+	}
 	}
 
 	template<typename T>
@@ -162,6 +172,8 @@ class Serializer : public SerializeBase
 	{
 		Version v = Current;
 		serialize(v);
+		if (settings.platform.isConsole())
+			serialize(settings.platform.ram_size);
 	}
 
 	template<typename T>
diff --git a/shell/libretro/libretro_core_options.h b/shell/libretro/libretro_core_options.h
index c5664cd02e..2e1a927d17 100644
--- a/shell/libretro/libretro_core_options.h
+++ b/shell/libretro/libretro_core_options.h
@@ -689,6 +689,20 @@ struct retro_core_option_v2_definition option_defs_us[] = {
       "disabled",
 #endif
    },
+   {
+      CORE_OPTION_NAME "_dc_32mb_mod",
+      "Dreamcast 32MB RAM Mod",
+      NULL,
+      "Enables 32MB RAM Mod for Dreamcast. May affect compatibility",
+      NULL,
+      "hacks",
+      {
+         { "disabled", NULL },
+         { "enabled", NULL },
+         {  NULL, NULL },
+      },
+      "disabled",
+   },
    {
       CORE_OPTION_NAME "_sh4clock",
       "SH4 CPU under/overclock",
diff --git a/shell/libretro/option.cpp b/shell/libretro/option.cpp
index 066e635733..f593db076a 100644
--- a/shell/libretro/option.cpp
+++ b/shell/libretro/option.cpp
@@ -101,6 +101,7 @@ Option<bool> UseReios(CORE_OPTION_NAME "_hle_bios");
 
 Option<bool> OpenGlChecks("", false);
 Option<bool> FastGDRomLoad(CORE_OPTION_NAME "_gdrom_fast_loading", false);
+Option<bool> RamMod32MB(CORE_OPTION_NAME "_dc_32mb_mod", false);
 
 //Option<std::vector<std::string>, false> ContentPath("");
 //Option<bool, false> HideLegacyNaomiRoms("", true);
diff --git a/tests/src/serialize_test.cpp b/tests/src/serialize_test.cpp
index 47e5a7a0b1..16ad3d8837 100644
--- a/tests/src/serialize_test.cpp
+++ b/tests/src/serialize_test.cpp
@@ -32,7 +32,7 @@ TEST_F(SerializeTest, SizeTest)
 	std::vector<char> data(30000000);
 	Serializer ser(data.data(), data.size());
 	dc_serialize(ser);
-	ASSERT_EQ(28191378u, ser.size());
+	ASSERT_EQ(28191382u, ser.size());
 }