Add a framework to support non-SRAM GBA saves

The support is not yet there, but at least
we should not read or write bogus data.

3 files changed, 170 insertions, 37 deletions

diff --git a/src/GBACart.cpp b/src/GBACart.cpp
index 10f5106..937958c 100644
--- a/src/GBACart.cpp
+++ b/src/GBACart.cpp
@@ -26,11 +26,40 @@
 namespace GBACart_SRAM

 {

 

+

+enum SaveType {

+    S_NULL,

+    S_EEPROM4K,

+    S_EEPROM64K,

+    S_SRAM256K,

+    S_FLASH512K,

+    S_FLASH1M

+};

+

+struct FlashProperties

+{

+    u8 state;

+    u8 cmd;

+    u8 device;

+    u8 manufacturer;

+    u8 bank;

+};

+

 u8* SRAM;

 u32 SRAMLength;

+SaveType SRAMType;

+FlashProperties SRAMFlash;

 

 char SRAMPath[1024];

 

+void (*WriteFunc)(u32 addr, u8 val);

+

+

+void Write_Null(u32 addr, u8 val);

+void Write_EEPROM(u32 addr, u8 val);

+void Write_SRAM(u32 addr, u8 val);

+void Write_Flash(u32 addr, u8 val);

+

 

 bool Init()

 {

@@ -47,6 +76,9 @@ void Reset()
 {

     if (SRAM) delete[] SRAM;

     SRAM = NULL;

+    SRAMLength = 0;

+    SRAMType = S_NULL;

+    SRAMFlash = {};

 }

 

 void DoSavestate(Savestate* file)

@@ -60,6 +92,7 @@ void LoadSave(const char* path)
 

     strncpy(SRAMPath, path, 1023);

     SRAMPath[1023] = '\0';

+    SRAMLength = 0;

 

     FILE* f = Platform::OpenFile(path, "rb");

     if (f)

@@ -73,12 +106,48 @@ void LoadSave(const char* path)
 

         fclose(f);

     }

-    else

+

+    switch (SRAMLength)

     {

-        int SRAMLength = 65536; // max GBA SRAM size

+    case 512:

+        SRAMType = S_EEPROM4K;

+        WriteFunc = Write_EEPROM;

+        break;

+    case 8192:

+        SRAMType = S_EEPROM64K;

+        WriteFunc = Write_EEPROM;

+        break;

+    case 32768:

+        SRAMType = S_SRAM256K;

+        WriteFunc = Write_SRAM;

+        break;

+    case 65536:

+        SRAMType = S_FLASH512K;

+        WriteFunc = Write_Flash;

+        break;

+    case 128*1024:

+        SRAMType = S_FLASH1M;

+        WriteFunc = Write_Flash;

+        break;

+    default:

+        printf("!! BAD SAVE LENGTH %d\n", SRAMLength);

+    case 0:

+        SRAMType = S_NULL;

+        WriteFunc = Write_Null;

+        break;

+    }

 

-        SRAM = new u8[SRAMLength];

-        memset(SRAM, 0xFF, SRAMLength);

+    if (SRAMType == S_FLASH512K)

+    {

+        // Panasonic 64K chip

+        SRAMFlash.device = 0x1B;

+        SRAMFlash.manufacturer = 0x32;

+    }

+    else if (SRAMType == S_FLASH1M)

+    {

+        // Macronix 128K chip

+        SRAMFlash.device = 0x09;

+        SRAMFlash.manufacturer = 0xC2;

     }

 }

 

@@ -104,21 +173,93 @@ void RelocateSave(const char* path, bool write)
     fclose(f);

 }

 

+u8 Read_Flash(u32 addr)

+{

+    // TODO: pokemen

+    return 0xFF;

+}

+

+void Write_Null(u32 addr, u8 val) {}

+

+void Write_EEPROM(u32 addr, u8 val)

+{

+    // TODO: could be used in homebrew?

+}

+

+void Write_Flash(u32 addr, u8 val)

+{

+    // TODO: pokemen

+}

+

+void Write_SRAM(u32 addr, u8 val)

+{

+    *(u8*)&SRAM[addr] = val;

+

+    // bit wasteful to do this for every written byte

+    FILE* f = Platform::OpenFile(SRAMPath, "r+b");

+    if (f)

+    {

+        fseek(f, addr, SEEK_SET);

+        fwrite((u8*)&SRAM[addr], 1, 1, f);

+        fclose(f);

+    }

+}

+

+u8 Read8(u32 addr)

+{

+    if (SRAMType == S_NULL)

+    {

+        return 0xFF;

+    }

+

+    if (SRAMType == S_FLASH512K || SRAMType == S_FLASH1M)

+    {

+        return Read_Flash(addr);

+    }

+

+    return *(u8*)&SRAM[addr];

+}

+

+u16 Read16(u32 addr)

+{

+    if (SRAMType == S_NULL)

+    {

+        return 0xFFFF;

+    }

+

+    if (SRAMType == S_FLASH512K || SRAMType == S_FLASH1M)

+    {

+        return Read_Flash(addr) & (Read_Flash(addr + 1) << 8);

+    }

+

+    return *(u16*)&SRAM[addr];

+}

+

+u32 Read32(u32 addr)

+{

+    if (SRAMType == S_NULL)

+    {

+        return 0xFFFFFFFF;

+    }

+

+    if (SRAMType == S_FLASH512K || SRAMType == S_FLASH1M)

+    {

+        return Read_Flash(addr) &

+            (Read_Flash(addr + 1) << 8) &

+            (Read_Flash(addr + 2) << 16) &

+            (Read_Flash(addr + 3) << 24);

+    }

+

+    return *(u32*)&SRAM[addr];

+}

+

 void Write8(u32 addr, u8 val)

 {

     u8 prev = *(u8*)&SRAM[addr];

 

     if (prev != val)

     {

-        *(u8*)&SRAM[addr] = val;/*

-

-        FILE* f = Platform::OpenFile(SRAMPath, "r+b");

-        if (f)

-        {

-            fseek(f, addr, SEEK_SET);

-            fwrite((u8*)&SRAM[addr], 1, 1, f);

-            fclose(f);

-        }*/

+        WriteFunc(addr, val);

     }

 }

 

@@ -128,15 +269,8 @@ void Write16(u32 addr, u16 val)
 

     if (prev != val)

     {

-        *(u16*)&SRAM[addr] = val;/*

-

-        FILE* f = Platform::OpenFile(SRAMPath, "r+b");

-        if (f)

-        {

-            fseek(f, addr, SEEK_SET);

-            fwrite((u8*)&SRAM[addr], 2, 1, f);

-            fclose(f);

-        }*/

+        WriteFunc(addr, val & 0xFF);

+        WriteFunc(addr + 1, val >> 8 & 0xFF);

     }

 }

 

@@ -146,15 +280,10 @@ void Write32(u32 addr, u32 val)
 

     if (prev != val)

     {

-        *(u32*)&SRAM[addr] = val;/*

-

-        FILE* f = Platform::OpenFile(SRAMPath, "r+b");

-        if (f)

-        {

-            fseek(f, addr, SEEK_SET);

-            fwrite((u8*)&SRAM[addr], 3, 1, f);

-            fclose(f);

-        }*/

+        WriteFunc(addr, val & 0xFF);

+        WriteFunc(addr + 1, val >> 8 & 0xFF);

+        WriteFunc(addr + 2, val >> 16 & 0xFF);

+        WriteFunc(addr + 3, val >> 24 & 0xFF);

     }

 }

 

diff --git a/src/GBACart.h b/src/GBACart.h
index e86ea43..81fb222 100644
--- a/src/GBACart.h
+++ b/src/GBACart.h
@@ -29,6 +29,10 @@ namespace GBACart_SRAM
 extern u8* SRAM;

 extern u32 SRAMLength;

 

+u8 Read8(u32 addr);

+u16 Read16(u32 addr);

+u32 Read32(u32 addr);

+

 void Write8(u32 addr, u8 val);

 void Write16(u32 addr, u16 val);

 void Write32(u32 addr, u32 val);

diff --git a/src/NDS.cpp b/src/NDS.cpp
index fe66814..a906fbb 100644
--- a/src/NDS.cpp
+++ b/src/NDS.cpp
@@ -1639,7 +1639,7 @@ u8 ARM9Read8(u32 addr)
         if (ExMemCnt[0] & (1<<7)) return 0x00; // deselected CPU is 00h-filled
         if (GBACart::CartInserted)
         {
-            return *(u8*)&GBACart_SRAM::SRAM[addr & (GBACart_SRAM::SRAMLength-1)];
+            return GBACart_SRAM::Read8(addr & (GBACart_SRAM::SRAMLength-1));
         }
         return 0xFF; // TODO: proper open bus
     }
@@ -1704,7 +1704,7 @@ u16 ARM9Read16(u32 addr)
         if (ExMemCnt[0] & (1<<7)) return 0x0000; // deselected CPU is 00h-filled
         if (GBACart::CartInserted)
         {
-            return *(u16*)&GBACart_SRAM::SRAM[addr & (GBACart_SRAM::SRAMLength-1)];
+            return GBACart_SRAM::Read16(addr & (GBACart_SRAM::SRAMLength-1));
         }
         return 0xFFFF; // TODO: proper open bus
     }
@@ -1769,7 +1769,7 @@ u32 ARM9Read32(u32 addr)
         if (ExMemCnt[0] & (1<<7)) return 0x00000000; // deselected CPU is 00h-filled
         if (GBACart::CartInserted)
         {
-            return *(u32*)&GBACart_SRAM::SRAM[addr & (GBACart_SRAM::SRAMLength-1)];
+            return GBACart_SRAM::Read32(addr & (GBACart_SRAM::SRAMLength-1));
         }
         return 0xFFFFFFFF; // TODO: proper open bus
     }
@@ -2000,7 +2000,7 @@ u8 ARM7Read8(u32 addr)
         if (!(ExMemCnt[0] & (1<<7))) return 0x00; // deselected CPU is 00h-filled
         if (GBACart::CartInserted)
         {
-            return *(u8*)&GBACart_SRAM::SRAM[addr & (GBACart_SRAM::SRAMLength-1)];
+            return GBACart_SRAM::Read8(addr & (GBACart_SRAM::SRAMLength-1));
         }
         return 0xFF; // TODO: proper open bus
     }
@@ -2067,7 +2067,7 @@ u16 ARM7Read16(u32 addr)
         if (!(ExMemCnt[0] & (1<<7))) return 0x0000; // deselected CPU is 00h-filled
         if (GBACart::CartInserted)
         {
-            return *(u16*)&GBACart_SRAM::SRAM[addr & (GBACart_SRAM::SRAMLength-1)];
+            return GBACart_SRAM::Read16(addr & (GBACart_SRAM::SRAMLength-1));
         }
         return 0xFFFF; // TODO: proper open bus
     }
@@ -2134,7 +2134,7 @@ u32 ARM7Read32(u32 addr)
         if (!(ExMemCnt[0] & (1<<7))) return 0x00000000; // deselected CPU is 00h-filled
         if (GBACart::CartInserted)
         {
-            return *(u32*)&GBACart_SRAM::SRAM[addr & (GBACart_SRAM::SRAMLength-1)];
+            return GBACart_SRAM::Read32(addr & (GBACart_SRAM::SRAMLength-1));
         }
         return 0xFFFFFFFF; // TODO: proper open bus
     }