Simplify SGB related UIs

src/BizHawk.Client.Common/RomLoader.cs

@@ -507,11 +507,6 @@ private void LoadOther(
 						);
 						return;
 					}
-
-					if (_config.GbAsSgb)
-					{
-						game.System = VSystemID.Raw.SGB;
-					}
 					break;
 				case VSystemID.Raw.PSX when ext is ".bin":
 					if (TryLoadSiblingCue(
@@ -1012,11 +1007,6 @@ private void DispatchErrorMessage(Exception ex, string system, string path)
 			{
 				DoLoadErrorCallback(ex.Message, system, path, Deterministic, LoadErrorType.MissingFirmware);
 			}
-			else if (ex is CGBNotSupportedException)
-			{
-				// failed to load SGB bios or game does not support SGB mode.
-				DoLoadErrorCallback("Failed to load a GB rom in SGB mode.  You might try disabling SGB Mode.", system);
-			}
 			else if (ex is NoAvailableCoreException)
 			{
 				// handle exceptions thrown by the new detected systems that BizHawk does not have cores for

src/BizHawk.Client.Common/config/Config.cs

@@ -31,11 +31,9 @@ public class Config
 			([ VSystemID.Raw.Satellaview ],
 				[ CoreNames.Bsnes115, CoreNames.SubBsnes115 ]),
 			([ VSystemID.Raw.GB, VSystemID.Raw.GBC ],
-				[ CoreNames.Gambatte, CoreNames.Sameboy, CoreNames.GbHawk, CoreNames.SubGbHawk ]),
+				[ CoreNames.Gambatte, CoreNames.Sameboy, CoreNames.GbHawk, CoreNames.SubGbHawk, CoreNames.Bsnes, CoreNames.Bsnes115, CoreNames.SubBsnes115 ]),
 			([ VSystemID.Raw.GBL ],
 				[ CoreNames.GambatteLink, CoreNames.GBHawkLink, CoreNames.GBHawkLink3x, CoreNames.GBHawkLink4x ]),
-			([ VSystemID.Raw.SGB ],
-				[ CoreNames.Gambatte, CoreNames.Bsnes115, CoreNames.SubBsnes115, CoreNames.Bsnes ]),
 			([ VSystemID.Raw.N64 ],
 				[ CoreNames.Mupen64Plus, CoreNames.Ares64 ]),
 			([ VSystemID.Raw.NES ],
@@ -411,8 +409,6 @@ public void SetWindowScaleFor(string sysID, int windowScale)
 		public Dictionary<string, Dictionary<string, AnalogBind>> AllTrollersAnalog { get; set; } = new Dictionary<string, Dictionary<string, AnalogBind>>();
 		public Dictionary<string, Dictionary<string, FeedbackBind>> AllTrollersFeedbacks { get; set; } = new Dictionary<string, Dictionary<string, FeedbackBind>>();
 
-		/// <remarks>as this setting spans multiple cores and doesn't actually affect the behavior of any core, it hasn't been absorbed into the new system</remarks>
-		public bool GbAsSgb { get; set; }
 		public string LibretroCore { get; set; }
 
 		public Dictionary<string, string> PreferredCores = GenDefaultCorePreferences();

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -147,17 +147,9 @@ private void MainForm_Load(object sender, EventArgs e)
 				CoresSubMenu.DropDownItems.Add(submenu);
 			}
 			CoresSubMenu.DropDownItems.Add(new ToolStripSeparator { AutoSize = true });
-			var GBInSGBMenuItem = new ToolStripMenuItem { Text = "GB in SGB" };
-			GBInSGBMenuItem.Click += (_, _) =>
-			{
-				Config.GbAsSgb = !Config.GbAsSgb;
-				if (Emulator.SystemId is VSystemID.Raw.GB or VSystemID.Raw.GBC or VSystemID.Raw.SGB) FlagNeedsReboot();
-			};
-			CoresSubMenu.DropDownItems.Add(GBInSGBMenuItem);
 			var setLibretroCoreToolStripMenuItem = new ToolStripMenuItem { Text = "Set Libretro Core..." };
 			setLibretroCoreToolStripMenuItem.Click += (_, _) => RunLibretroCoreChooser();
 			CoresSubMenu.DropDownItems.Add(setLibretroCoreToolStripMenuItem);
-			CoresSubMenu.DropDownOpened += (_, _) => GBInSGBMenuItem.Checked = Config.GbAsSgb;
 
 			ToolStripMenuItemEx recentCoreSettingsSubmenu = new() { Text = "Recent" };
 			recentCoreSettingsSubmenu.DropDownItems.AddRange(CreateCoreSettingsSubmenus().ToArray());

src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/BsnesCore.cs

@@ -16,8 +16,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 	[PortedCore(CoreNames.Bsnes115, "bsnes team", "v115+", "https://github.com/bsnes-emu/bsnes")]
 	public partial class BsnesCore : IEmulator, IDebuggable, IVideoProvider, ISaveRam, IStatable, IInputPollable, IRegionable, ISettable<BsnesCore.SnesSettings, BsnesCore.SnesSyncSettings>, IBSNESForGfxDebugger, IBoardInfo
 	{
+		[CoreConstructor(VSystemID.Raw.GB)]
+		[CoreConstructor(VSystemID.Raw.GBC)]
 		[CoreConstructor(VSystemID.Raw.Satellaview)]
-		[CoreConstructor(VSystemID.Raw.SGB)]
 		[CoreConstructor(VSystemID.Raw.SNES)]
 		public BsnesCore(CoreLoadParameters<SnesSettings, SnesSyncSettings> loadParameters) : this(loadParameters, false) { }
 		public BsnesCore(CoreLoadParameters<SnesSettings, SnesSyncSettings> loadParameters, bool subframe = false)
@@ -28,8 +29,8 @@ public BsnesCore(CoreLoadParameters<SnesSettings, SnesSyncSettings> loadParamete
 			this._romPath = Path.ChangeExtension(loadParameters.Roms[0].RomPath.SubstringBefore('|'), null);
 			CoreComm = loadParameters.Comm;
 			_syncSettings = loadParameters.SyncSettings ?? new SnesSyncSettings();
-			SystemId = loadParameters.Game.System;
-			_isSGB = SystemId == VSystemID.Raw.SGB;
+			_isSGB = loadParameters.Game.System is VSystemID.Raw.GB or VSystemID.Raw.GBC;
+			SystemId = _isSGB ? VSystemID.Raw.SGB : loadParameters.Game.System;
 			_currentMsuTrack = new ProxiedFile();
 
 			byte[] sgbRomData = null;

src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/SubBsnesCore.cs

@@ -11,8 +11,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 		portedUrl: "https://github.com/bsnes-emu/bsnes")]
 	public class SubBsnesCore : IEmulator, ICycleTiming
 	{
+		[CoreConstructor(VSystemID.Raw.GB)]
+		[CoreConstructor(VSystemID.Raw.GBC)]
 		[CoreConstructor(VSystemID.Raw.Satellaview)]
-		[CoreConstructor(VSystemID.Raw.SGB)]
 		[CoreConstructor(VSystemID.Raw.SNES)]
 		public SubBsnesCore(CoreLoadParameters<BsnesCore.SnesSettings, BsnesCore.SnesSyncSettings> loadParameters)
 		{

src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.ISettable.cs

@@ -115,7 +115,7 @@ public enum ConsoleModeType
 			}
 
 			[DisplayName("Console Mode")]
-			[Description("Picks which console to emulate. 'SGB2' is always in effect when 'GB in SGB' is checked.")]
+			[Description("Picks which console to emulate.")]
 			[DefaultValue(ConsoleModeType.Auto)]
 			public ConsoleModeType ConsoleMode { get; set; }
 

src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs

@@ -20,8 +20,7 @@ public partial class Gameboy : IInputPollable, IRomInfo, IGameboyCommon, ICycleT
 
 		[CoreConstructor(VSystemID.Raw.GB)]
 		[CoreConstructor(VSystemID.Raw.GBC)]
-		[CoreConstructor(VSystemID.Raw.SGB)]
-		public Gameboy(CoreComm comm, IGameInfo game, byte[] file, GambatteSettings settings, GambatteSyncSettings syncSettings, bool deterministic)
+		public Gameboy(CoreComm comm, GameInfo game, byte[] file, GambatteSettings settings, GambatteSyncSettings syncSettings, bool deterministic)
 		{
 			_serviceProvider = new(this);
 			_serviceProvider.Register<IDisassemblable>(_disassembler);

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SNES/LibsnesCore.cs

@@ -22,7 +22,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 	public unsafe partial class LibsnesCore : IEmulator, IVideoProvider, ISaveRam, IStatable, IInputPollable, IRegionable, ICodeDataLogger,
 		IDebuggable, ISettable<LibsnesCore.SnesSettings, LibsnesCore.SnesSyncSettings>, IBSNESForGfxDebugger
 	{
-		[CoreConstructor(VSystemID.Raw.SGB)]
+		[CoreConstructor(VSystemID.Raw.GB)]
+		[CoreConstructor(VSystemID.Raw.GBC)]
 		[CoreConstructor(VSystemID.Raw.SNES)]
 		public LibsnesCore(GameInfo game, byte[] rom, CoreComm comm,
 			LibsnesCore.SnesSettings settings, LibsnesCore.SnesSyncSettings syncSettings)
@@ -44,8 +45,9 @@ public LibsnesCore(GameInfo game, byte[] romData, byte[] xmlData, string baseRom
 			_game = game;
 			CoreComm = comm;
 			byte[] sgbRomData = null;
+			IsSGB = game.System is VSystemID.Raw.GB or VSystemID.Raw.GBC;
 
-			if (game.System == VSystemID.Raw.SGB)
+			if (IsSGB)
 			{
 				if ((romData[0x143] & 0xc0) == 0xc0)
 				{
@@ -109,9 +111,8 @@ public LibsnesCore(GameInfo game, byte[] romData, byte[] xmlData, string baseRom
 				romData = newData;
 			}
 
-			if (game.System == VSystemID.Raw.SGB)
+			if (IsSGB)
 			{
-				IsSGB = true;
 				SystemId = VSystemID.Raw.SNES;
 				ser.Register<IBoardInfo>(new SGBBoardInfo());