From 8a0093de231c399c712bf1e15a94ae393195dc7b Mon Sep 17 00:00:00 2001
From: TotalNerd <xtrafear@gmail.com>
Date: Tue, 8 Jul 2014 12:06:11 -0500
Subject: [PATCH] Emulate GameCube memory card speeds

---
 Source/Core/Core/HW/EXI_DeviceMemoryCard.cpp | 44 +++++++++++++++++---
 Source/Core/Core/HW/EXI_DeviceMemoryCard.h   | 11 +++++
 2 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/Source/Core/Core/HW/EXI_DeviceMemoryCard.cpp b/Source/Core/Core/HW/EXI_DeviceMemoryCard.cpp
index 809e1c79ba..d311feff74 100644
--- a/Source/Core/Core/HW/EXI_DeviceMemoryCard.cpp
+++ b/Source/Core/Core/HW/EXI_DeviceMemoryCard.cpp
@@ -18,6 +18,7 @@
 #include "Core/HW/GCMemcardRaw.h"
 #include "Core/HW/Memmap.h"
 #include "Core/HW/Sram.h"
+#include "Core/HW/SystemTimers.h"
 #include "DiscIO/NANDContentLoader.h"
 
 #define MC_STATUS_BUSY              0x80
@@ -28,6 +29,12 @@
 #define MC_STATUS_READY             0x01
 #define SIZE_TO_Mb (1024 * 8 * 16)
 
+// These are rough estimates based on GameCube video evidence of memory card "speeds"
+// This will need to be refined, and perhaps the idea behind the speed thing is wrong
+// But it works with (near?) perfect speed as far as saving goes
+static const float MC_TRANSFER_RATE_WRITE = 22.0f * 1024.0f;
+static const float MC_TRANSFER_RATE_READ = 73.84f * 1024.0f;
+
 void CEXIMemoryCard::FlushCallback(u64 userdata, int cyclesLate)
 {
 	// note that userdata is forbidden to be a pointer, due to the implementation of EventDoState
@@ -227,26 +234,47 @@ void CEXIMemoryCard::SetCS(int cs)
 
 				//???
 
-				CmdDoneLater(5000);
+				if (address >= MC_DATA_FILES)
+					CmdDoneLater(BLOCK_SIZE * (SystemTimers::GetTicksPerSecond() / MC_TRANSFER_RATE_WRITE));
+				else
+					CmdDoneLater(5000);
 			}
 			break;
 
 		case cmdChipErase:
 			if (m_uPosition > 2)
 			{
-				// TODO: Investigate on HW, I (LPFaint99) believe that this only erases the system area (Blocks 0-4)
-				memorycard->ClearAll();
+				// Clear only the system blocks
+				for (int i = 0; i < 5; i++)
+					memorycard->ClearBlock(BLOCK_SIZE * i);
+
 				status &= ~MC_STATUS_BUSY;
 				m_bDirty = true;
+
+				if (address >= MC_DATA_FILES)
+					CmdDoneLater((BLOCK_SIZE * 5) * (SystemTimers::GetTicksPerSecond() / MC_TRANSFER_RATE_WRITE));
+				else
+					CmdDoneLater(5000);
+			}
+			break;
+
+		case cmdReadArray:
+			if (m_uPosition > 8)
+			{
+				// Each read is 512 bytes
+				if (address >= MC_DATA_FILES)
+					CmdDoneLater(512 * (SystemTimers::GetTicksPerSecond() / MC_TRANSFER_RATE_READ));
+				else
+					CmdDoneLater(5000);
 			}
 			break;
 
 		case cmdPageProgram:
-			if (m_uPosition >= 5)
+			if (m_uPosition > 4)
 			{
 				int count = m_uPosition - 5;
 				int i=0;
-				status &= ~0x80;
+				status &= ~MC_STATUS_BUSY;
 
 				while (count--)
 				{
@@ -255,7 +283,11 @@ void CEXIMemoryCard::SetCS(int cs)
 					address = (address & ~0x1FF) | ((address+1) & 0x1FF);
 				}
 
-				CmdDoneLater(5000);
+				// Each write is 128 bytes
+				if (address >= MC_DATA_FILES)
+					CmdDoneLater(128 * (SystemTimers::GetTicksPerSecond() / MC_TRANSFER_RATE_WRITE));
+				else
+					CmdDoneLater(5000);
 			}
 			break;
 		}
diff --git a/Source/Core/Core/HW/EXI_DeviceMemoryCard.h b/Source/Core/Core/HW/EXI_DeviceMemoryCard.h
index 12747268ed..ce7bdc87d8 100644
--- a/Source/Core/Core/HW/EXI_DeviceMemoryCard.h
+++ b/Source/Core/Core/HW/EXI_DeviceMemoryCard.h
@@ -39,6 +39,17 @@ private:
 	// Variant of CmdDone which schedules an event later in the future to complete the command.
 	void CmdDoneLater(u64 cycles);
 
+	// Memory card data layout
+	enum
+	{
+		MC_DATA_HEADER = 0x0000,
+		MC_DATA_DIRECTORY = 0x2000,
+		MC_DATA_DIRECTORYBACKUP = 0x4000,
+		MC_DATA_BLOCKALLOCMAP = 0x6000,
+		MC_DATA_BLOCKALLOCMAPBACKUP = 0x8000,
+		MC_DATA_FILES = 0xA000,
+	};
+
 	enum
 	{
 		cmdNintendoID       = 0x00,