diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp
index 42124939aa..6f422ef79c 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp
@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include "Core/HW/DSPHLE/UCodes/AX.h"
+
 #include "Common/ChunkFile.h"
 #include "Common/CommonFuncs.h"
 #include "Common/CommonTypes.h"
@@ -10,6 +11,8 @@
 #include "Common/Logging/Log.h"
 #include "Common/MathUtil.h"
 #include "Core/HW/DSP.h"
+#include "Core/HW/DSPHLE/DSPHLE.h"
+#include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/AXStructs.h"
 
 #define AX_GC
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AX.h b/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
index e3dde4d2b9..7220f14c1a 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
@@ -19,6 +19,8 @@ namespace DSP
 {
 namespace HLE
 {
+class DSPHLE;
+
 // We can't directly use the mixer_control field from the PB because it does
 // not mean the same in all AX versions. The AX UCode converts the
 // mixer_control value to an AXMixControl bitfield.
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp
index 7edd9c1d0f..469844d225 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp
@@ -5,12 +5,15 @@
 #define AX_WII  // Used in AXVoice.
 
 #include "Core/HW/DSPHLE/UCodes/AXWii.h"
+
 #include "Common/ChunkFile.h"
 #include "Common/CommonFuncs.h"
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
 #include "Common/MathUtil.h"
 #include "Common/StringUtil.h"
+#include "Core/HW/DSPHLE/DSPHLE.h"
+#include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/AXStructs.h"
 #include "Core/HW/DSPHLE/UCodes/AXVoice.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
index a2c9a34278..0f397af968 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/AX.h"
 
 namespace DSP
@@ -11,6 +12,7 @@ namespace DSP
 namespace HLE
 {
 struct AXPBWii;
+class DSPHLE;
 
 class AXWiiUCode : public AXUCode
 {
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp
index 124d0a5f47..3533cb6a89 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp
@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include "Core/HW/DSPHLE/UCodes/CARD.h"
+
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
 #include "Core/HW/DSP.h"
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h
index 8963119347..1dff96bc40 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h
@@ -4,12 +4,15 @@
 
 #pragma once
 
+#include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
 namespace DSP
 {
 namespace HLE
 {
+class DSPHLE;
+
 class CARDUCode : public UCodeInterface
 {
 public:
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp
index 5c62b1698e..586930c395 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp
@@ -3,11 +3,14 @@
 // Refer to the license.txt file included.
 
 #include "Core/HW/DSPHLE/UCodes/GBA.h"
+
 #include "Common/Align.h"
 #include "Common/CommonFuncs.h"
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
 #include "Core/HW/DSP.h"
+#include "Core/HW/DSPHLE/DSPHLE.h"
+#include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
 namespace DSP
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h
index be5df0ef07..214de61e53 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h
@@ -4,12 +4,15 @@
 
 #pragma once
 
+#include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
 namespace DSP
 {
 namespace HLE
 {
+class DSPHLE;
+
 // Computes two 32 bit integers to be returned to the game, based on the
 // provided crypto parameters at the provided MRAM address. The integers are
 // written back to RAM at the dest address provided in the crypto parameters.
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp
index ff41c9a6d7..b359e98ccf 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp
@@ -3,8 +3,11 @@
 // Refer to the license.txt file included.
 
 #include "Core/HW/DSPHLE/UCodes/INIT.h"
+
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
+#include "Core/HW/DSPHLE/DSPHLE.h"
+#include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
 namespace DSP
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h
index fc7add50e0..4383b98441 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h
@@ -4,12 +4,15 @@
 
 #pragma once
 
+#include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
 namespace DSP
 {
 namespace HLE
 {
+class DSPHLE;
+
 class INITUCode : public UCodeInterface
 {
 public:
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp
index 8d0a88acfd..8b3c3b68a8 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp
@@ -2,6 +2,8 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
+#include "Core/HW/DSPHLE/UCodes/ROM.h"
+
 #include <string>
 
 #ifdef _WIN32
@@ -15,7 +17,8 @@
 #include "Common/Logging/Log.h"
 #include "Common/StringUtil.h"
 #include "Core/ConfigManager.h"
-#include "Core/HW/DSPHLE/UCodes/ROM.h"
+#include "Core/HW/DSPHLE/DSPHLE.h"
+#include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
 namespace DSP
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h
index 9c2df6f035..25a79835b2 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h
@@ -4,12 +4,15 @@
 
 #pragma once
 
+#include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
 namespace DSP
 {
 namespace HLE
 {
+class DSPHLE;
+
 class ROMUCode : public UCodeInterface
 {
 public:
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp
index 71e0aa4d3a..86c578e999 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp
@@ -2,6 +2,9 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
+#include "Core/HW/DSPHLE/UCodes/UCodes.h"
+
+#include <cstring>
 #include <string>
 
 #ifdef _WIN32
@@ -9,110 +12,123 @@
 #endif
 
 #include "Common/ChunkFile.h"
+#include "Common/CommonFuncs.h"
 #include "Common/CommonTypes.h"
 #include "Common/FileUtil.h"
 #include "Common/Hash.h"
 #include "Common/Logging/Log.h"
 #include "Common/StringUtil.h"
 #include "Core/ConfigManager.h"
+#include "Core/HW/DSPHLE/DSPHLE.h"
 #include "Core/HW/DSPHLE/UCodes/AX.h"
 #include "Core/HW/DSPHLE/UCodes/AXWii.h"
 #include "Core/HW/DSPHLE/UCodes/CARD.h"
 #include "Core/HW/DSPHLE/UCodes/GBA.h"
 #include "Core/HW/DSPHLE/UCodes/INIT.h"
 #include "Core/HW/DSPHLE/UCodes/ROM.h"
-#include "Core/HW/DSPHLE/UCodes/UCodes.h"
 #include "Core/HW/DSPHLE/UCodes/Zelda.h"
+#include "Core/HW/Memmap.h"
 
 namespace DSP
 {
 namespace HLE
 {
-UCodeInterface* UCodeFactory(u32 crc, DSPHLE* dsphle, bool wii)
+constexpr bool ExramRead(u32 address)
 {
-  switch (crc)
-  {
-  case UCODE_ROM:
-    INFO_LOG(DSPHLE, "Switching to ROM ucode");
-    return new ROMUCode(dsphle, crc);
-
-  case UCODE_INIT_AUDIO_SYSTEM:
-    INFO_LOG(DSPHLE, "Switching to INIT ucode");
-    return new INITUCode(dsphle, crc);
-
-  case 0x65d6cc6f:  // CARD
-    INFO_LOG(DSPHLE, "Switching to CARD ucode");
-    return new CARDUCode(dsphle, crc);
-
-  case 0xdd7e72d5:
-    INFO_LOG(DSPHLE, "Switching to GBA ucode");
-    return new GBAUCode(dsphle, crc);
-
-  case 0x3ad3b7ac:  // Naruto 3, Paper Mario - The Thousand Year Door
-  case 0x3daf59b9:  // Alien Hominid
-  case 0x4e8a8b21:  // spdemo, Crazy Taxi, 18 Wheeler, Disney, Monkeyball 1/2, Cubivore, Nintendo
-                    // Puzzle Collection, Wario,
-  // Capcom vs. SNK 2, Naruto 2, Lost Kingdoms, Star Fox, Mario Party 4, Mortal Kombat,
-  // Smugglers Run Warzone, Smash Brothers, Sonic Mega Collection, ZooCube
-  // nddemo, Star Fox
-  case 0x07f88145:  // bustamove, Ikaruga, F-Zero GX, Robotech Battle Cry, Star Soldier, Soul
-                    // Calibur 2,
-                    // Zelda:OOT, Tony Hawk, Viewtiful Joe
-  case 0xe2136399:  // Billy Hatcher, Dragon Ball Z, Mario Party 5, TMNT, 1080° Avalanche
-  case 0x3389a79e:  // MP1/MP2 Wii (Metroid Prime Trilogy)
-    INFO_LOG(DSPHLE, "CRC %08x: AX ucode chosen", crc);
-    return new AXUCode(dsphle, crc);
-
-  case 0x86840740:  // Zelda WW - US
-  case 0x6ca33a6d:  // Zelda TP GC - US
-  case 0xd643001f:  // Super Mario Galaxy - US
-  case 0x6ba3b3ea:  // GC IPL - PAL
-  case 0x24b22038:  // GC IPL - US
-  case 0x2fcdf1ec:  // Zelda FSA - US
-  case 0x4be6a5cb:  // Pikmin 1 GC - US
-  case 0x267fd05a:  // Pikmin 1 GC - PAL
-  case 0x42f64ac4:  // Luigi's Mansion - US
-  case 0x56d36052:  // Super Mario Sunshine - US
-  case 0x6c3f6f94:  // Zelda TP Wii - US
-  case 0xb7eb9a9c:  // Pikmin 1 New Play Control Wii - US
-  case 0xeaeb38cc:  // Pikmin 2 New Play Control Wii - US
-    return new ZeldaUCode(dsphle, crc);
-
-  case 0x2ea36ce6:  // Some Wii demos
-  case 0x5ef56da3:  // AX demo
-  case 0x347112ba:  // Raving Rabbids
-  case 0xfa450138:  // Wii Sports - PAL
-  case 0xadbc06bd:  // Elebits
-  case 0x4cc52064:  // Bleach: Versus Crusade
-  case 0xd9c4bf34:  // WiiMenu
-    INFO_LOG(DSPHLE, "CRC %08x: Wii - AXWii chosen", crc);
-    return new AXWiiUCode(dsphle, crc);
-
-  default:
-    if (wii)
-    {
-      PanicAlertT("This title might be incompatible with DSP HLE emulation. Try using LLE if this "
-                  "is homebrew.\n\n"
-                  "Unknown ucode (CRC = %08x) - forcing AXWii.",
-                  crc);
-      return new AXWiiUCode(dsphle, crc);
-    }
-    else
-    {
-      PanicAlertT("This title might be incompatible with DSP HLE emulation. Try using LLE if this "
-                  "is homebrew.\n\n"
-                  "DSPHLE: Unknown ucode (CRC = %08x) - forcing AX.",
-                  crc);
-      return new AXUCode(dsphle, crc);
-    }
-
-  case UCODE_NULL:
-    break;
-  }
-
-  return nullptr;
+  return (address & 0x10000000) != 0;
 }
 
+u8 HLEMemory_Read_U8(u32 address)
+{
+  if (ExramRead(address))
+    return Memory::m_pEXRAM[address & Memory::EXRAM_MASK];
+
+  return Memory::m_pRAM[address & Memory::RAM_MASK];
+}
+
+void HLEMemory_Write_U8(u32 address, u8 value)
+{
+  if (ExramRead(address))
+    Memory::m_pEXRAM[address & Memory::EXRAM_MASK] = value;
+  else
+    Memory::m_pRAM[address & Memory::RAM_MASK] = value;
+}
+
+u16 HLEMemory_Read_U16LE(u32 address)
+{
+  u16 value;
+
+  if (ExramRead(address))
+    std::memcpy(&value, &Memory::m_pEXRAM[address & Memory::EXRAM_MASK], sizeof(u16));
+  else
+    std::memcpy(&value, &Memory::m_pRAM[address & Memory::RAM_MASK], sizeof(u16));
+
+  return value;
+}
+
+u16 HLEMemory_Read_U16(u32 address)
+{
+  return Common::swap16(HLEMemory_Read_U16LE(address));
+}
+
+void HLEMemory_Write_U16LE(u32 address, u16 value)
+{
+  if (ExramRead(address))
+    std::memcpy(&Memory::m_pEXRAM[address & Memory::EXRAM_MASK], &value, sizeof(u16));
+  else
+    std::memcpy(&Memory::m_pRAM[address & Memory::RAM_MASK], &value, sizeof(u16));
+}
+
+void HLEMemory_Write_U16(u32 address, u16 value)
+{
+  HLEMemory_Write_U16LE(address, Common::swap16(value));
+}
+
+u32 HLEMemory_Read_U32LE(u32 address)
+{
+  u32 value;
+
+  if (ExramRead(address))
+    std::memcpy(&value, &Memory::m_pEXRAM[address & Memory::EXRAM_MASK], sizeof(u32));
+  else
+    std::memcpy(&value, &Memory::m_pRAM[address & Memory::RAM_MASK], sizeof(u32));
+
+  return value;
+}
+
+u32 HLEMemory_Read_U32(u32 address)
+{
+  return Common::swap32(HLEMemory_Read_U32LE(address));
+}
+
+void HLEMemory_Write_U32LE(u32 address, u32 value)
+{
+  if (ExramRead(address))
+    std::memcpy(&Memory::m_pEXRAM[address & Memory::EXRAM_MASK], &value, sizeof(u32));
+  else
+    std::memcpy(&Memory::m_pRAM[address & Memory::RAM_MASK], &value, sizeof(u32));
+}
+
+void HLEMemory_Write_U32(u32 address, u32 value)
+{
+  HLEMemory_Write_U32LE(address, Common::swap32(value));
+}
+
+void* HLEMemory_Get_Pointer(u32 address)
+{
+  if (ExramRead(address))
+    return &Memory::m_pEXRAM[address & Memory::EXRAM_MASK];
+
+  return &Memory::m_pRAM[address & Memory::RAM_MASK];
+}
+
+UCodeInterface::UCodeInterface(DSPHLE* dsphle, u32 crc)
+    : m_mail_handler(dsphle->AccessMailHandler()), m_dsphle(dsphle), m_crc(crc)
+{
+}
+
+UCodeInterface::~UCodeInterface() = default;
+
 bool UCodeInterface::NeedsResumeMail()
 {
   if (m_needs_resume_mail)
@@ -210,5 +226,90 @@ void UCodeInterface::DoStateShared(PointerWrap& p)
   p.Do(m_next_ucode_steps);
   p.Do(m_needs_resume_mail);
 }
+
+UCodeInterface* UCodeFactory(u32 crc, DSPHLE* dsphle, bool wii)
+{
+  switch (crc)
+  {
+  case UCODE_ROM:
+    INFO_LOG(DSPHLE, "Switching to ROM ucode");
+    return new ROMUCode(dsphle, crc);
+
+  case UCODE_INIT_AUDIO_SYSTEM:
+    INFO_LOG(DSPHLE, "Switching to INIT ucode");
+    return new INITUCode(dsphle, crc);
+
+  case 0x65d6cc6f:  // CARD
+    INFO_LOG(DSPHLE, "Switching to CARD ucode");
+    return new CARDUCode(dsphle, crc);
+
+  case 0xdd7e72d5:
+    INFO_LOG(DSPHLE, "Switching to GBA ucode");
+    return new GBAUCode(dsphle, crc);
+
+  case 0x3ad3b7ac:  // Naruto 3, Paper Mario - The Thousand Year Door
+  case 0x3daf59b9:  // Alien Hominid
+  case 0x4e8a8b21:  // spdemo, Crazy Taxi, 18 Wheeler, Disney, Monkeyball 1/2, Cubivore, Nintendo
+                    // Puzzle Collection, Wario,
+  // Capcom vs. SNK 2, Naruto 2, Lost Kingdoms, Star Fox, Mario Party 4, Mortal Kombat,
+  // Smugglers Run Warzone, Smash Brothers, Sonic Mega Collection, ZooCube
+  // nddemo, Star Fox
+  case 0x07f88145:  // bustamove, Ikaruga, F-Zero GX, Robotech Battle Cry, Star Soldier, Soul
+                    // Calibur 2,
+                    // Zelda:OOT, Tony Hawk, Viewtiful Joe
+  case 0xe2136399:  // Billy Hatcher, Dragon Ball Z, Mario Party 5, TMNT, 1080° Avalanche
+  case 0x3389a79e:  // MP1/MP2 Wii (Metroid Prime Trilogy)
+    INFO_LOG(DSPHLE, "CRC %08x: AX ucode chosen", crc);
+    return new AXUCode(dsphle, crc);
+
+  case 0x86840740:  // Zelda WW - US
+  case 0x6ca33a6d:  // Zelda TP GC - US
+  case 0xd643001f:  // Super Mario Galaxy - US
+  case 0x6ba3b3ea:  // GC IPL - PAL
+  case 0x24b22038:  // GC IPL - US
+  case 0x2fcdf1ec:  // Zelda FSA - US
+  case 0x4be6a5cb:  // Pikmin 1 GC - US
+  case 0x267fd05a:  // Pikmin 1 GC - PAL
+  case 0x42f64ac4:  // Luigi's Mansion - US
+  case 0x56d36052:  // Super Mario Sunshine - US
+  case 0x6c3f6f94:  // Zelda TP Wii - US
+  case 0xb7eb9a9c:  // Pikmin 1 New Play Control Wii - US
+  case 0xeaeb38cc:  // Pikmin 2 New Play Control Wii - US
+    return new ZeldaUCode(dsphle, crc);
+
+  case 0x2ea36ce6:  // Some Wii demos
+  case 0x5ef56da3:  // AX demo
+  case 0x347112ba:  // Raving Rabbids
+  case 0xfa450138:  // Wii Sports - PAL
+  case 0xadbc06bd:  // Elebits
+  case 0x4cc52064:  // Bleach: Versus Crusade
+  case 0xd9c4bf34:  // WiiMenu
+    INFO_LOG(DSPHLE, "CRC %08x: Wii - AXWii chosen", crc);
+    return new AXWiiUCode(dsphle, crc);
+
+  default:
+    if (wii)
+    {
+      PanicAlertT("This title might be incompatible with DSP HLE emulation. Try using LLE if this "
+                  "is homebrew.\n\n"
+                  "Unknown ucode (CRC = %08x) - forcing AXWii.",
+                  crc);
+      return new AXWiiUCode(dsphle, crc);
+    }
+    else
+    {
+      PanicAlertT("This title might be incompatible with DSP HLE emulation. Try using LLE if this "
+                  "is homebrew.\n\n"
+                  "DSPHLE: Unknown ucode (CRC = %08x) - forcing AX.",
+                  crc);
+      return new AXUCode(dsphle, crc);
+    }
+
+  case UCODE_NULL:
+    break;
+  }
+
+  return nullptr;
+}
 }  // namespace HLE
 }  // namespace DSP
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h
index d6dde298ab..80894d7674 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h
@@ -7,8 +7,6 @@
 #include <cstring>
 
 #include "Common/CommonTypes.h"
-#include "Core/HW/DSPHLE/DSPHLE.h"
-#include "Core/HW/Memmap.h"
 
 class PointerWrap;
 
@@ -17,111 +15,35 @@ namespace DSP
 namespace HLE
 {
 class CMailHandler;
+class DSPHLE;
 
 #define UCODE_ROM 0x00000000
 #define UCODE_INIT_AUDIO_SYSTEM 0x00000001
 #define UCODE_NULL 0xFFFFFFFF
 
-constexpr bool ExramRead(u32 address)
-{
-  return (address & 0x10000000) != 0;
-}
+u8 HLEMemory_Read_U8(u32 address);
+void HLEMemory_Write_U8(u32 address, u8 value);
 
-inline u8 HLEMemory_Read_U8(u32 address)
-{
-  if (ExramRead(address))
-    return Memory::m_pEXRAM[address & Memory::EXRAM_MASK];
-  else
-    return Memory::m_pRAM[address & Memory::RAM_MASK];
-}
+u16 HLEMemory_Read_U16LE(u32 address);
+u16 HLEMemory_Read_U16(u32 address);
 
-inline void HLEMemory_Write_U8(u32 address, u8 value)
-{
-  if (ExramRead(address))
-    Memory::m_pEXRAM[address & Memory::EXRAM_MASK] = value;
-  else
-    Memory::m_pRAM[address & Memory::RAM_MASK] = value;
-}
+void HLEMemory_Write_U16LE(u32 address, u16 value);
+void HLEMemory_Write_U16(u32 address, u16 value);
 
-inline u16 HLEMemory_Read_U16LE(u32 address)
-{
-  u16 value;
+u32 HLEMemory_Read_U32LE(u32 address);
+u32 HLEMemory_Read_U32(u32 address);
 
-  if (ExramRead(address))
-    std::memcpy(&value, &Memory::m_pEXRAM[address & Memory::EXRAM_MASK], sizeof(u16));
-  else
-    std::memcpy(&value, &Memory::m_pRAM[address & Memory::RAM_MASK], sizeof(u16));
+void HLEMemory_Write_U32LE(u32 address, u32 value);
+void HLEMemory_Write_U32(u32 address, u32 value);
 
-  return value;
-}
-
-inline u16 HLEMemory_Read_U16(u32 address)
-{
-  return Common::swap16(HLEMemory_Read_U16LE(address));
-}
-
-inline void HLEMemory_Write_U16LE(u32 address, u16 value)
-{
-  if (ExramRead(address))
-    std::memcpy(&Memory::m_pEXRAM[address & Memory::EXRAM_MASK], &value, sizeof(u16));
-  else
-    std::memcpy(&Memory::m_pRAM[address & Memory::RAM_MASK], &value, sizeof(u16));
-}
-
-inline void HLEMemory_Write_U16(u32 address, u16 value)
-{
-  HLEMemory_Write_U16LE(address, Common::swap16(value));
-}
-
-inline u32 HLEMemory_Read_U32LE(u32 address)
-{
-  u32 value;
-
-  if (ExramRead(address))
-    std::memcpy(&value, &Memory::m_pEXRAM[address & Memory::EXRAM_MASK], sizeof(u32));
-  else
-    std::memcpy(&value, &Memory::m_pRAM[address & Memory::RAM_MASK], sizeof(u32));
-
-  return value;
-}
-
-inline u32 HLEMemory_Read_U32(u32 address)
-{
-  return Common::swap32(HLEMemory_Read_U32LE(address));
-}
-
-inline void HLEMemory_Write_U32LE(u32 address, u32 value)
-{
-  if (ExramRead(address))
-    std::memcpy(&Memory::m_pEXRAM[address & Memory::EXRAM_MASK], &value, sizeof(u32));
-  else
-    std::memcpy(&Memory::m_pRAM[address & Memory::RAM_MASK], &value, sizeof(u32));
-}
-
-inline void HLEMemory_Write_U32(u32 address, u32 value)
-{
-  HLEMemory_Write_U32LE(address, Common::swap32(value));
-}
-
-inline void* HLEMemory_Get_Pointer(u32 address)
-{
-  if (ExramRead(address))
-    return &Memory::m_pEXRAM[address & Memory::EXRAM_MASK];
-  else
-    return &Memory::m_pRAM[address & Memory::RAM_MASK];
-}
+void* HLEMemory_Get_Pointer(u32 address);
 
 class UCodeInterface
 {
 public:
-  UCodeInterface(DSPHLE* dsphle, u32 crc)
-      : m_mail_handler(dsphle->AccessMailHandler()), m_upload_setup_in_progress(false),
-        m_dsphle(dsphle), m_crc(crc), m_next_ucode(), m_next_ucode_steps(0),
-        m_needs_resume_mail(false)
-  {
-  }
+  UCodeInterface(DSPHLE* dsphle, u32 crc);
+  virtual ~UCodeInterface();
 
-  virtual ~UCodeInterface() {}
   virtual void Initialize() = 0;
   virtual void HandleMail(u32 mail) = 0;
   virtual void Update() = 0;
@@ -152,7 +74,7 @@ protected:
 
   // UCode is forwarding mails to PrepareBootUCode
   // UCode only needs to set this to true, UCodeInterface will set to false when done!
-  bool m_upload_setup_in_progress;
+  bool m_upload_setup_in_progress = false;
 
   // Need a pointer back to DSPHLE to switch ucodes.
   DSPHLE* m_dsphle;
@@ -175,10 +97,10 @@ private:
     u16 dram_size;
     u16 dram_dest;
   };
-  NextUCodeInfo m_next_ucode;
-  int m_next_ucode_steps;
+  NextUCodeInfo m_next_ucode{};
+  int m_next_ucode_steps = 0;
 
-  bool m_needs_resume_mail;
+  bool m_needs_resume_mail = false;
 };
 
 UCodeInterface* UCodeFactory(u32 crc, DSPHLE* dsphle, bool wii);
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
index 08e1470d0a..7f848cb63f 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
@@ -2,16 +2,19 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
+#include "Core/HW/DSPHLE/UCodes/Zelda.h"
+
 #include <array>
 
 #include "Common/ChunkFile.h"
 #include "Common/CommonFuncs.h"
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
+#include "Core/HW/DSP.h"
+#include "Core/HW/DSPHLE/DSPHLE.h"
 #include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/GBA.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
-#include "Core/HW/DSPHLE/UCodes/Zelda.h"
 
 namespace DSP
 {
@@ -372,6 +375,31 @@ void ZeldaUCode::HandleMailLight(u32 mail)
   }
 }
 
+void ZeldaUCode::SetMailState(MailState new_state)
+{
+  // WARN_LOG(DSPHLE, "MailState %d -> %d", m_mail_current_state, new_state);
+  m_mail_current_state = new_state;
+}
+
+u32 ZeldaUCode::Read32()
+{
+  if (m_read_offset == m_write_offset)
+  {
+    ERROR_LOG(DSPHLE, "Reading too many command params");
+    return 0;
+  }
+
+  u32 res = m_cmd_buffer[m_read_offset];
+  m_read_offset = (m_read_offset + 1) % (sizeof(m_cmd_buffer) / sizeof(u32));
+  return res;
+}
+
+void ZeldaUCode::Write32(u32 val)
+{
+  m_cmd_buffer[m_write_offset] = val;
+  m_write_offset = (m_write_offset + 1) % (sizeof(m_cmd_buffer) / sizeof(u32));
+}
+
 void ZeldaUCode::RunPendingCommands()
 {
   if (RenderingInProgress() || !m_cmd_can_execute)
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h
index f5d6469d6a..ebce34d09b 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <array>
+
 #include "Common/CommonTypes.h"
 #include "Common/MathUtil.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
@@ -12,6 +14,8 @@ namespace DSP
 {
 namespace HLE
 {
+class DSPHLE;
+
 class ZeldaAudioRenderer
 {
 public:
@@ -226,11 +230,7 @@ private:
 
   // Utility function to set the current state. Useful for debugging and
   // logging as a hook point.
-  void SetMailState(MailState new_state)
-  {
-    // WARN_LOG(DSPHLE, "MailState %d -> %d", m_mail_current_state, new_state);
-    m_mail_current_state = new_state;
-  }
+  void SetMailState(MailState new_state);
 
   // Voice synchronization / audio rendering flow control. When rendering an
   // audio frame, only voices up to max_voice_id will be rendered until a
@@ -251,25 +251,10 @@ private:
   bool m_cmd_can_execute = true;
 
   // Reads a 32 bit value from the command buffer. Advances the read pointer.
-  u32 Read32()
-  {
-    if (m_read_offset == m_write_offset)
-    {
-      ERROR_LOG(DSPHLE, "Reading too many command params");
-      return 0;
-    }
-
-    u32 res = m_cmd_buffer[m_read_offset];
-    m_read_offset = (m_read_offset + 1) % (sizeof(m_cmd_buffer) / sizeof(u32));
-    return res;
-  }
+  u32 Read32();
 
   // Writes a 32 bit value to the command buffer. Advances the write pointer.
-  void Write32(u32 val)
-  {
-    m_cmd_buffer[m_write_offset] = val;
-    m_write_offset = (m_write_offset + 1) % (sizeof(m_cmd_buffer) / sizeof(u32));
-  }
+  void Write32(u32 val);
 
   // Tries to run as many commands as possible until either the command
   // buffer is empty (pending_commands == 0) or we reached a long lived