diff --git a/core/hw/flashrom/flashrom.h b/core/hw/flashrom/flashrom.h
index a04d185b1..15896eed4 100644
--- a/core/hw/flashrom/flashrom.h
+++ b/core/hw/flashrom/flashrom.h
@@ -23,19 +23,19 @@ struct MemChip
 	}
 	virtual ~MemChip() { delete[] data; }
 
-	virtual u8 Read8(u32 addr)
+	u8 Read8(u32 addr)
 	{
-		return data[addr&mask];
+		return data[addr & mask];
 	}
 
 	u32 Read(u32 addr,u32 sz) 
 	{
-		addr&=mask;
+		addr &= mask;
 
-		u32 rv=0;
+		u32 rv = 0;
 
-		for (u32 i=0;i<sz;i++)
-			rv|=Read8(addr+i)<<(i*8);
+		for (u32 i = 0; i < sz; i++)
+			rv |= Read8(addr + i) << (i * 8);
 
 		return rv;
 	}
@@ -250,36 +250,6 @@ struct DCFlashChip : MemChip
 		state = FS_Normal;
 	}
 	
-	virtual u8 Read8(u32 addr) override
-	{
-		if (settings.platform.system == DC_PLATFORM_DREAMCAST)
-		{
-			switch (addr)
-			{
-			case 0x1A002:
-			case 0x1A0A2:
-				if (settings.dreamcast.region <= 2)
-					return '0' + settings.dreamcast.region;
-				break;
-			case 0x1A003:
-			case 0x1A0A3:
-				if (settings.dreamcast.language <= 5)
-					return '0' + settings.dreamcast.language;
-				break;
-			case 0x1A004:
-			case 0x1A0A4:
-				if (settings.dreamcast.broadcast <= 3)
-					return '0' + settings.dreamcast.broadcast;
-				break;
-			}
-		}
-
-		u32 rv=MemChip::Read8(addr);
-
-		return rv;
-	}
-	
-
 	void Write(u32 addr,u32 val,u32 sz) override
 	{
 		if (sz != 1)
@@ -492,6 +462,61 @@ struct DCFlashChip : MemChip
 		}
 	}
 
+	void Validate()
+	{
+		// validate partition 0 (factory settings)
+		bool valid = true;
+		char sysinfo[16];
+
+		for (int i = 0; i < sizeof(sysinfo); i++)
+			sysinfo[i] = Read8(0x1a000 + i);
+		valid = valid && memcmp(&sysinfo[5], "Dreamcast  ", 11) == 0;
+
+		for (int i = 0; i < sizeof(sysinfo); i++)
+			sysinfo[i] = Read8(0x1a0a0 + i);
+		valid = valid && memcmp(&sysinfo[5], "Dreamcast  ", 11) == 0;
+
+		if (!valid)
+		{
+			INFO_LOG(FLASHROM, "DCFlashChip::Validate resetting FLASH_PT_FACTORY");
+
+			memcpy(sysinfo, "00000Dreamcast  ", sizeof(sysinfo));
+			erase_partition(FLASH_PT_FACTORY);
+			memcpy(data + 0x1a000, sysinfo, sizeof(sysinfo));
+			memcpy(data + 0x1a0a0, sysinfo, sizeof(sysinfo));
+		}
+
+		// validate partition 1 (reserved)
+		erase_partition(FLASH_PT_RESERVED);
+
+		// validate partition 2 (user settings, block allocated)
+		if (!validate_header(FLASH_PT_USER))
+		{
+			INFO_LOG(FLASHROM, "DCFlashChip::Validate resetting FLASH_PT_USER");
+
+			erase_partition(FLASH_PT_USER);
+			write_header(FLASH_PT_USER);
+		}
+
+		// validate partition 3 (game settings, block allocated)
+		if (!validate_header(FLASH_PT_GAME))
+		{
+			INFO_LOG(FLASHROM, "DCFlashChip::Validate resetting FLASH_PT_GAME");
+
+			erase_partition(FLASH_PT_GAME);
+			write_header(FLASH_PT_GAME);
+		}
+
+		// validate partition 4 (unknown, block allocated)
+		if (!validate_header(FLASH_PT_UNKNOWN))
+		{
+			INFO_LOG(FLASHROM, "DCFlashChip::Validate resetting FLASH_PT_UNKNOWN");
+
+			erase_partition(FLASH_PT_UNKNOWN);
+			write_header(FLASH_PT_UNKNOWN);
+		}
+	}
+
 private:
 	int crc_block(struct flash_user_block *block)
 	{
@@ -570,6 +595,14 @@ private:
 		return 1;
 	}
 
+	int validate_header(u32 part_id)
+	{
+		int offset, size;
+		GetPartitionInfo(part_id, &offset, &size);
+
+		return validate_header(offset, part_id);
+	}
+
 	int alloc_block(u32 offset, u32 size)
 	{
 		u8 bitmap[FLASH_BLOCK_SIZE];
@@ -655,4 +688,26 @@ private:
 		REICAST_USA(&this->data[write_protect_size], size - write_protect_size);
 		return true;
 	}
+
+	void erase_partition(u32 part_id)
+	{
+		int offset, size;
+		GetPartitionInfo(part_id, &offset, &size);
+
+		memset(data + offset, 0xFF, size);
+	}
+
+	void write_header(int part_id)
+	{
+		int offset, size;
+		GetPartitionInfo(part_id, &offset, &size);
+
+		struct flash_header_block header;
+		memset(&header, 0xff, sizeof(header));
+		memcpy(header.magic, FLASH_MAGIC_COOKIE, sizeof(header.magic));
+		header.part_id = part_id;
+		header.version = 0;
+
+		write_physical_block(offset, 0, &header);
+	}
 };
diff --git a/core/hw/holly/sb_mem.cpp b/core/hw/holly/sb_mem.cpp
index 0ea46a3a0..72c906cc2 100644
--- a/core/hw/holly/sb_mem.cpp
+++ b/core/hw/holly/sb_mem.cpp
@@ -74,20 +74,30 @@ bool LoadRomFiles(const string& root)
 	else
 		rc = sys_nvmem->Load(get_game_save_prefix() + ".nvmem");
 	if (!rc)
-	{
-		if (nvmemOptional())
-		{
-			INFO_LOG(FLASHROM, "flash/nvmem is missing, will create new file...");
-		}
-		else
-		{
-			msgboxf("Unable to find flash/nvmem in %s. Exiting...", MBX_ICONERROR, root.c_str());
-			return false;
-		}
-	}
+		INFO_LOG(FLASHROM, "flash/nvmem is missing, will create new file...");
 
 	if (settings.platform.system == DC_PLATFORM_DREAMCAST)
 	{
+		static_cast<DCFlashChip*>(sys_nvmem)->Validate();
+
+		// overwrite factory flash settings
+		if (settings.dreamcast.region <= 2)
+		{
+			sys_nvmem->data[0x1a002] = '0' + settings.dreamcast.region;
+			sys_nvmem->data[0x1a0a2] = '0' + settings.dreamcast.region;
+		}
+		if (settings.dreamcast.language <= 5)
+		{
+			sys_nvmem->data[0x1a003] = '0' + settings.dreamcast.language;
+			sys_nvmem->data[0x1a0a3] = '0' + settings.dreamcast.language;
+		}
+		if (settings.dreamcast.broadcast <= 3)
+		{
+			sys_nvmem->data[0x1a004] = '0' + settings.dreamcast.broadcast;
+			sys_nvmem->data[0x1a0a4] = '0' + settings.dreamcast.broadcast;
+		}
+
+		// overwrite user settings
 		struct flash_syscfg_block syscfg;
 		int res = static_cast<DCFlashChip*>(sys_nvmem)->ReadBlock(FLASH_PT_USER, FLASH_USER_SYSCFG, &syscfg);
 
diff --git a/core/reios/gdrom_hle.cpp b/core/reios/gdrom_hle.cpp
index f6b60ceef..3243667fd 100644
--- a/core/reios/gdrom_hle.cpp
+++ b/core/reios/gdrom_hle.cpp
@@ -140,7 +140,6 @@ void GD_HLE_Command(u32 cc, u32 prm)
 		break;
 
 	case GDCC_GETSES:
-		debugf("GDROM: GETSES CC:%X PRM:%X", cc, prm);
 		GDROM_HLE_ReadSES(prm);
 		break;
 
@@ -153,7 +152,6 @@ void GD_HLE_Command(u32 cc, u32 prm)
 		break;
 
 	case GDCC_DMAREAD:
-		debugf("GDROM: CMD DMAREAD CC:%X PRM:%X", cc, prm);
 		GDROM_HLE_ReadDMA(prm);
 		break;
 
@@ -194,7 +192,6 @@ void GD_HLE_Command(u32 cc, u32 prm)
 		break;
 
 	case GDCC_GETSCD:
-		debugf("GDROM: GETSCD CC:%X PRM:%X",cc,prm);
 		GDCC_HLE_GETSCD(prm);
 		break;
 
@@ -318,7 +315,7 @@ void gdrom_hle_op()
 		switch(r[7])				// COMMAND CODE
 		{
 		case GDROM_SEND_COMMAND:	// SEND GDROM COMMAND RET: - if failed + req id
-			debugf("GDROM: HLE SEND COMMAND CC:%X  param ptr: %X", r[4], r[5]);
+			//debugf("GDROM: HLE SEND COMMAND CC:%X  param ptr: %X", r[4], r[5]);
 			memset(bios_result, 0, sizeof(bios_result));
 			LastCommandId = r[0] = NextCommandId++;		// Request Id
 			GD_HLE_Command(r[4], r[5]);
@@ -337,7 +334,7 @@ void gdrom_hle_op()
 			{
 				r[0] = 2;	// Finished
 			}
-			debugf("GDROM: HLE CHECK COMMAND REQID:%X  param ptr: %X -> %X", r[4], r[5], r[0]);
+			//debugf("GDROM: HLE CHECK COMMAND REQID:%X  param ptr: %X -> %X", r[4], r[5], r[0]);
 			LastCommandId = 0xFFFFFFFF;			// INVALIDATE CHECK CMD
 			WriteMem32(r[5], bios_result[0]);
 			WriteMem32(r[5] + 4, bios_result[1]);
diff --git a/core/reios/reios.cpp b/core/reios/reios.cpp
index 4febc9236..21222d272 100644
--- a/core/reios/reios.cpp
+++ b/core/reios/reios.cpp
@@ -259,16 +259,12 @@ static void reios_sys_flashrom() {
 		case 0: // FLASHROM_INFO
 			{
 				/*
-						r4 = partition number(0 - 4)
-						r5 = pointer to two 32 bit integers to receive the result.
-							The first will be the offset of the partition start, in bytes from the start of the flashrom.
-							The second will be the size of the partition, in bytes.
-
-							#define FLASHROM_PT_SYSTEM      0   /< \brief Factory settings (read-only, 8K)
-							#define FLASHROM_PT_RESERVED    1   /< \brief reserved (all 0s, 8K)
-							#define FLASHROM_PT_BLOCK_1     2   /< \brief Block allocated (16K)
-							#define FLASHROM_PT_SETTINGS    3   /< \brief Game settings (block allocated, 32K)
-							#define FLASHROM_PT_BLOCK_2     4   /< \brief Block allocated (64K)
+					r4 = partition number(0 - 4)
+					r5 = pointer to two 32 bit integers to receive the result.
+						The first will be the offset of the partition start, in bytes from the start of the flashrom.
+						The second will be the size of the partition, in bytes.
+					returns:
+					r0 = 0 if partition found, -1 if error or not found
 				 */
 
 				u32 part = Sh4cntx.r[4];
@@ -291,9 +287,11 @@ static void reios_sys_flashrom() {
 		case 1:	//FLASHROM_READ
 			{
 				/*
-				r4 = read start position, in bytes from the start of the flashrom
-				r5 = pointer to destination buffer
-				r6 = number of bytes to read
+					r4 = read start position, in bytes from the start of the flashrom
+					r5 = pointer to destination buffer
+					r6 = number of bytes to read
+					returns:
+					r0 = number of bytes read
 				*/
 				u32 offset = Sh4cntx.r[4];
 				u32 dest = Sh4cntx.r[5];
@@ -314,6 +312,8 @@ static void reios_sys_flashrom() {
 					r4 = write start position, in bytes from the start of the flashrom
 					r5 = pointer to source buffer
 					r6 = number of bytes to write
+					returns:
+					r0 = number of bytes written
 				*/
 
 				u32 offs = Sh4cntx.r[4];
@@ -323,14 +323,16 @@ static void reios_sys_flashrom() {
 				debugf("reios_sys_flashrom: FLASHROM_WRITE offs %x src %08x size %x", offs, src, size);
 				u8* pSrc = GetMemPtr(src, size);
 
-				for (int i = 0; i < size; i++) {
+				for (int i = 0; i < size; i++)
 					flashrom->data[offs + i] &= pSrc[i];
-				}
+
+				Sh4cntx.r[0] = size;
 			}
 			break;
 
 		case 3:	//FLASHROM_DELETE
 			{			
+				// offset of partition to delete
 				u32 offset = Sh4cntx.r[4];
 
 				debugf("reios_sys_flashrom: FLASHROM_DELETE offs %x", offset);