diff --git a/src/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs b/src/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs
index b5472ef955..bb1992d1bc 100644
--- a/src/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs
+++ b/src/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs
@@ -280,7 +280,7 @@ namespace BizHawk.Emulation.Common
 			var jp_mcd_beta = File("F30D109D1C2F7C9FEAF38600C65834261DB73D1F", 131072, "MCD_jp_beta.bin", "Mega CD JP (Beta)");
 			var eu_mcd_221 = File("9DE4EDA59F544DB2D5FD7E6514601F7B648D8EB4", 131072, "MCD_eu_221.bin", "Mega CD EU (v2.21)");
 
-			FirmwareAndOption("1C470A9A8D0B211C5FEEA1C1C2376AA1F7934B16", 4096, "GEN", "TMSS", "TMSS.md", "Mega Drive TMSS Boot Rom (Japan)");
+			FirmwareAndOption("3F50B76B0529DB7F79C396B5E808CC0786FFC311", 2048, "GEN", "Boot", "GEN_boot.md", "Genesis Boot Rom (World)");
 
 			Firmware("GEN", "CD_BIOS_EU", "Mega CD Bios (Europe)");
 			Firmware("GEN", "CD_BIOS_JP", "Mega CD Bios (Japan)");
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IMemoryDomains.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IMemoryDomains.cs
index 51c5ae5eb9..41a861fa87 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IMemoryDomains.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IMemoryDomains.cs
@@ -26,7 +26,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 					var name = Marshal.PtrToStringAnsi(pName)!;
 
 					// typically Genesis domains will be 2 bytes large (and thus big endian and byteswapped)
-					var oneByteWidth = name is "Z80 RAM" or "Main RAM" or "ROM" or "Cart (Volatile) RAM" or "SRAM";
+					var oneByteWidth = name is "Z80 RAM" or "Main RAM" or "ROM" or "BOOT ROM" or "Cart (Volatile) RAM" or "SRAM";
 
 					var endian = oneByteWidth
 						? MemoryDomain.Endian.Little
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs
index 058aeebf04..e6739e5f16 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs
@@ -148,8 +148,11 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
 				KillMemCallbacks();
 
-				_tracer = new GPGXTraceBuffer(this, _memoryDomains, this);
-				((BasicServiceProvider)ServiceProvider).Register(_tracer);
+				if (SystemId == VSystemID.Raw.GEN)
+				{
+					_tracer = new GPGXTraceBuffer(this, _memoryDomains, this);
+					((BasicServiceProvider)ServiceProvider).Register(_tracer);
+				}
 			}
 
 			_romfile = null;
@@ -261,7 +264,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
  				FirmwareID? firmwareID = filename switch
  				{
-					"MD_BIOS" => new(system: VSystemID.Raw.GEN, firmware: "TMSS"),
+					"MD_BIOS" => new(system: VSystemID.Raw.GEN, firmware: "Boot"),
  					"CD_BIOS_EU" => new(system: VSystemID.Raw.GEN, firmware: "CD_BIOS_EU"),
  					"CD_BIOS_JP" => new(system: VSystemID.Raw.GEN, firmware: "CD_BIOS_JP"),
  					"CD_BIOS_US" => new(system: VSystemID.Raw.GEN, firmware: "CD_BIOS_US"),