diff --git a/Source/Core/Core/HW/GCMemcard.cpp b/Source/Core/Core/HW/GCMemcard.cpp
index c08b798458..85a26e4ac8 100644
--- a/Source/Core/Core/HW/GCMemcard.cpp
+++ b/Source/Core/Core/HW/GCMemcard.cpp
@@ -250,7 +250,7 @@ bool GCMemcard::Save()
   return mcdFile.Close();
 }
 
-void calc_checksumsBE(u16* buf, u32 length, u16* csum, u16* inv_csum)
+void calc_checksumsBE(const u16* buf, u32 length, u16* csum, u16* inv_csum)
 {
   *csum = *inv_csum = 0;
 
@@ -639,7 +639,7 @@ u32 GCMemcard::GetSaveData(u8 index, std::vector<GCMBlock>& Blocks) const
 }
 // End DEntry functions
 
-u32 GCMemcard::ImportFile(DEntry& direntry, std::vector<GCMBlock>& saveBlocks)
+u32 GCMemcard::ImportFile(const DEntry& direntry, std::vector<GCMBlock>& saveBlocks)
 {
   if (!m_valid)
     return NOMEMCARD;
@@ -1271,7 +1271,7 @@ bool GCMemcard::Format(bool shift_jis, u16 SizeMb)
 /* Returns: Error code                                       */
 /*************************************************************/
 
-s32 GCMemcard::FZEROGX_MakeSaveGameValid(Header& cardheader, DEntry& direntry,
+s32 GCMemcard::FZEROGX_MakeSaveGameValid(const Header& cardheader, const DEntry& direntry,
                                          std::vector<GCMBlock>& FileBuffer)
 {
   u32 i, j;
@@ -1280,7 +1280,7 @@ s32 GCMemcard::FZEROGX_MakeSaveGameValid(Header& cardheader, DEntry& direntry,
   int block = 0;
 
   // check for F-Zero GX system file
-  if (strcmp((char*)direntry.Filename, "f_zero.dat") != 0)
+  if (strcmp(reinterpret_cast<const char*>(direntry.Filename), "f_zero.dat") != 0)
     return 0;
 
   // get encrypted destination memory card serial numbers
@@ -1324,7 +1324,7 @@ s32 GCMemcard::FZEROGX_MakeSaveGameValid(Header& cardheader, DEntry& direntry,
 /* Returns: Error code                                     */
 /***********************************************************/
 
-s32 GCMemcard::PSO_MakeSaveGameValid(Header& cardheader, DEntry& direntry,
+s32 GCMemcard::PSO_MakeSaveGameValid(const Header& cardheader, const DEntry& direntry,
                                      std::vector<GCMBlock>& FileBuffer)
 {
   u32 i, j;
@@ -1334,10 +1334,10 @@ s32 GCMemcard::PSO_MakeSaveGameValid(Header& cardheader, DEntry& direntry,
   u32 pso3offset = 0x00;
 
   // check for PSO1&2 system file
-  if (strcmp((char*)direntry.Filename, "PSO_SYSTEM") != 0)
+  if (strcmp(reinterpret_cast<const char*>(direntry.Filename), "PSO_SYSTEM") != 0)
   {
     // check for PSO3 system file
-    if (strcmp((char*)direntry.Filename, "PSO3_SYSTEM") == 0)
+    if (strcmp(reinterpret_cast<const char*>(direntry.Filename), "PSO3_SYSTEM") == 0)
     {
       // PSO3 data block size adjustment
       pso3offset = 0x10;
diff --git a/Source/Core/Core/HW/GCMemcard.h b/Source/Core/Core/HW/GCMemcard.h
index c609cc5dd7..b6be07df33 100644
--- a/Source/Core/Core/HW/GCMemcard.h
+++ b/Source/Core/Core/HW/GCMemcard.h
@@ -76,7 +76,7 @@ public:
   }
   virtual ~MemoryCardBase() {}
   virtual s32 Read(u32 address, s32 length, u8* destaddress) = 0;
-  virtual s32 Write(u32 destaddress, s32 length, u8* srcaddress) = 0;
+  virtual s32 Write(u32 destaddress, s32 length, const u8* srcaddress) = 0;
   virtual void ClearBlock(u32 address) = 0;
   virtual void ClearAll() = 0;
   virtual void DoState(PointerWrap& p) = 0;
@@ -95,7 +95,7 @@ struct GCMBlock
   u8 block[BLOCK_SIZE];
 };
 
-void calc_checksumsBE(u16* buf, u32 length, u16* csum, u16* inv_csum);
+void calc_checksumsBE(const u16* buf, u32 length, u16* csum, u16* inv_csum);
 
 #pragma pack(push, 1)
 struct Header  // Offset    Size    Description
@@ -321,9 +321,9 @@ public:
   bool Save();
   bool Format(bool shift_jis = false, u16 SizeMb = MemCard2043Mb);
   static bool Format(u8* card_data, bool shift_jis = false, u16 SizeMb = MemCard2043Mb);
-  static s32 FZEROGX_MakeSaveGameValid(Header& cardheader, DEntry& direntry,
+  static s32 FZEROGX_MakeSaveGameValid(const Header& cardheader, const DEntry& direntry,
                                        std::vector<GCMBlock>& FileBuffer);
-  static s32 PSO_MakeSaveGameValid(Header& cardheader, DEntry& direntry,
+  static s32 PSO_MakeSaveGameValid(const Header& cardheader, const DEntry& direntry,
                                    std::vector<GCMBlock>& FileBuffer);
 
   u32 TestChecksums() const;
@@ -364,7 +364,7 @@ public:
   u32 GetSaveData(u8 index, std::vector<GCMBlock>& saveBlocks) const;
 
   // adds the file to the directory and copies its contents
-  u32 ImportFile(DEntry& direntry, std::vector<GCMBlock>& saveBlocks);
+  u32 ImportFile(const DEntry& direntry, std::vector<GCMBlock>& saveBlocks);
 
   // delete a file from the directory
   u32 RemoveFile(u8 index);
diff --git a/Source/Core/Core/HW/GCMemcardDirectory.cpp b/Source/Core/Core/HW/GCMemcardDirectory.cpp
index 69d177f052..489b5a4dce 100644
--- a/Source/Core/Core/HW/GCMemcardDirectory.cpp
+++ b/Source/Core/Core/HW/GCMemcardDirectory.cpp
@@ -270,7 +270,7 @@ s32 GCMemcardDirectory::Read(u32 address, s32 length, u8* destaddress)
   return length + extra;
 }
 
-s32 GCMemcardDirectory::Write(u32 destaddress, s32 length, u8* srcaddress)
+s32 GCMemcardDirectory::Write(u32 destaddress, s32 length, const u8* srcaddress)
 {
   std::unique_lock<std::mutex> l(m_write_mutex);
   if (length != 0x80)
@@ -475,7 +475,7 @@ inline s32 GCMemcardDirectory::SaveAreaRW(u32 block, bool writing)
   return -1;
 }
 
-s32 GCMemcardDirectory::DirectoryWrite(u32 destaddress, u32 length, u8* srcaddress)
+s32 GCMemcardDirectory::DirectoryWrite(u32 destaddress, u32 length, const u8* srcaddress)
 {
   u32 block = destaddress / BLOCK_SIZE;
   u32 offset = destaddress % BLOCK_SIZE;
diff --git a/Source/Core/Core/HW/GCMemcardDirectory.h b/Source/Core/Core/HW/GCMemcardDirectory.h
index 711dfda026..8a1dcba1c5 100644
--- a/Source/Core/Core/HW/GCMemcardDirectory.h
+++ b/Source/Core/Core/HW/GCMemcardDirectory.h
@@ -28,7 +28,7 @@ public:
   void FlushToFile();
   void FlushThread();
   s32 Read(u32 address, s32 length, u8* destaddress) override;
-  s32 Write(u32 destaddress, s32 length, u8* srcaddress) override;
+  s32 Write(u32 destaddress, s32 length, const u8* srcaddress) override;
   void ClearBlock(u32 address) override;
   void ClearAll() override {}
   void DoState(PointerWrap& p) override;
@@ -37,7 +37,7 @@ private:
   int LoadGCI(const std::string& fileName, DiscIO::Region card_region, bool currentGameOnly);
   inline s32 SaveAreaRW(u32 block, bool writing = false);
   // s32 DirectoryRead(u32 offset, u32 length, u8* destaddress);
-  s32 DirectoryWrite(u32 destaddress, u32 length, u8* srcaddress);
+  s32 DirectoryWrite(u32 destaddress, u32 length, const u8* srcaddress);
   inline void SyncSaves();
   bool SetUsedBlocks(int saveIndex);
 
diff --git a/Source/Core/Core/HW/GCMemcardRaw.cpp b/Source/Core/Core/HW/GCMemcardRaw.cpp
index 24c72b7f6f..ccb1566ee1 100644
--- a/Source/Core/Core/HW/GCMemcardRaw.cpp
+++ b/Source/Core/Core/HW/GCMemcardRaw.cpp
@@ -157,7 +157,7 @@ s32 MemoryCard::Read(u32 srcaddress, s32 length, u8* destaddress)
   return length;
 }
 
-s32 MemoryCard::Write(u32 destaddress, s32 length, u8* srcaddress)
+s32 MemoryCard::Write(u32 destaddress, s32 length, const u8* srcaddress)
 {
   if (!IsAddressInBounds(destaddress))
   {
diff --git a/Source/Core/Core/HW/GCMemcardRaw.h b/Source/Core/Core/HW/GCMemcardRaw.h
index 0b0e5cf637..fdd582658d 100644
--- a/Source/Core/Core/HW/GCMemcardRaw.h
+++ b/Source/Core/Core/HW/GCMemcardRaw.h
@@ -23,7 +23,7 @@ public:
   void MakeDirty();
 
   s32 Read(u32 address, s32 length, u8* destaddress) override;
-  s32 Write(u32 destaddress, s32 length, u8* srcaddress) override;
+  s32 Write(u32 destaddress, s32 length, const u8* srcaddress) override;
   void ClearBlock(u32 address) override;
   void ClearAll() override;
   void DoState(PointerWrap& p) override;