Better handling 768KB roms

drhelius · Jan 4, 2025 · a6be35d · a6be35d
1 parent bf86405
commit a6be35d
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Showing 2 changed files with 59 additions and 23 deletions.
diff --git a/src/cartridge.cpp b/src/cartridge.cpp
@@ -17,12 +17,13 @@
  *
  */
 
-#include "cartridge.h"
-#include "miniz/miniz.h"
-#include "game_db.h"
 #include <string>
 #include <fstream>
 #include <algorithm>
+#include <assert.h>
+#include "cartridge.h"
+#include "miniz/miniz.h"
+#include "game_db.h"
 
 Cartridge::Cartridge()
 {
@@ -185,6 +186,8 @@ bool Cartridge::LoadFromBuffer(const u8* buffer, int size)
             Debug("MCGENJIN mapper detected.");
         }
 
+        assert((size % 0x2000) == 0);
+
         if ((size % 0x2000) != 0)
         {
             Log("Invalid size found: %d (0x%X) bytes", size, size);
@@ -196,12 +199,6 @@ bool Cartridge::LoadFromBuffer(const u8* buffer, int size)
 
         GatherROMInfo();
 
-        if (m_is_sgx)
-        {
-            Log("SuperGrafx (SGX) games are not supported yet.");
-            return false;
-        }
-
         InitRomMAP();
 
         m_ready = true;
@@ -300,11 +297,17 @@ void Cartridge::GatherInfoFromDB()
             found = true;
             Log("ROM found in database: %s. CRC: %08X", k_game_database[i].title, m_crc);
 
-            if (k_game_database[i].flags & GG_GAMEDB_SGX)
+            if (k_game_database[i].flags & GG_GAMEDB_SGX_REQUIRED)
             {
                 m_is_sgx = true;
                 Log("ROM is a SuperGrafx (SGX) game.");
             }
+
+            if (k_game_database[i].flags & GG_GAMEDB_SGX_OPTIONAL)
+            {
+                m_is_sgx = true;
+                Log("ROM is a SuperGrafx (SGX) optional game.");
+            }
         }
         else
             i++;
@@ -318,8 +321,10 @@ void Cartridge::GatherInfoFromDB()
 
 void Cartridge::InitRomMAP()
 {
-    if(m_rom_size == 0x60000)
+    if (m_rom_bank_count == 0x30)
     {
+        Debug("Mapping 384KB ROM");
+
         for(int x = 0; x < 64; x++)
         {
             int bank = x & 0x1F;
@@ -329,13 +334,15 @@ void Cartridge::InitRomMAP()
 
         for(int x = 64; x < 128; x++)
         {
-            int bank = (x & 0x0F) + 32;
+            int bank = (x & 0x0F) + 0x20;
             int bank_address = bank * 0x2000;
             m_rom_map[x] = &m_rom[bank_address];
         }
     }
-    else if (m_rom_size == 0x80000)
+    else if (m_rom_bank_count == 0x40)
     {
+        Debug("Mapping 512KB ROM");
+
         for(int x = 0; x < 64; x++)
         {
             int bank = x & 0x3F;
@@ -345,16 +352,36 @@ void Cartridge::InitRomMAP()
 
         for(int x = 64; x < 128; x++)
         {
-            int bank = (x & 0x1F) + 32;
+            int bank = (x & 0x1F) + 0x20;
+            int bank_address = bank * 0x2000;
+            m_rom_map[x] = &m_rom[bank_address];
+        }
+    }
+    else if (m_rom_bank_count == 0x60)
+    {
+        Debug("Mapping 768KB ROM");
+
+        for(int x = 0; x < 64; x++)
+        {
+            int bank = x & 0x3F;
+            int bank_address = bank * 0x2000;
+            m_rom_map[x] = &m_rom[bank_address];
+        }
+
+        for(int x = 64; x < 128; x++)
+        {
+            int bank = (x & 0x1F) + 0x40;
             int bank_address = bank * 0x2000;
             m_rom_map[x] = &m_rom[bank_address];
         }
     }
     else
     {
+        Debug("Default mapping ROM");
+
         for(int x = 0; x < 128; x++)
         {
-            int bank = x % (m_rom_size / 0x2000);
+            int bank = x % m_rom_bank_count;
             int bank_address = bank * 0x2000;
             m_rom_map[x] = &m_rom[bank_address];
         }

diff --git a/src/game_db.h b/src/game_db.h
@@ -22,8 +22,10 @@
 
 #include "common.h"
 
-#define GG_GAMEDB_NONE 0x00
-#define GG_GAMEDB_SGX  0x01
+#define GG_GAMEDB_NONE          0x00
+#define GG_GAMEDB_SGX_REQUIRED  0x01
+#define GG_GAMEDB_SGX_OPTIONAL  0x02
+#define GG_GAMEDB_SF2_MAPPER    0x04
 
 struct GG_Game_DB_Entry
 {
@@ -34,12 +36,19 @@ struct GG_Game_DB_Entry
 
 const GG_Game_DB_Entry k_game_database[] =
 {
-    { 0xBEBFE042, "Darius Plus (J) (SGX)", GG_GAMEDB_SGX},
-    { 0x4C2126B0, "Aldynes (J) (SGX)", GG_GAMEDB_SGX},
-    { 0x8C4588E2, "1941 - Counter Attack (J) (SGX)", GG_GAMEDB_SGX},
-    { 0x1F041166, "Madouou Granzort (J) (SGX)", GG_GAMEDB_SGX},
-    { 0xB486A8ED, "Daimakaimura (J) (SGX)", GG_GAMEDB_SGX},
-    { 0x3B13AF61, "Battle Ace (J) (SGX)", GG_GAMEDB_SGX},
+    // SGX
+    { 0x8C4588E2, "1941 - Counter Attack (J) (SGX)", GG_GAMEDB_SGX_REQUIRED},
+    { 0x4C2126B0, "Aldynes (J) (SGX)", GG_GAMEDB_SGX_REQUIRED},
+    { 0x3B13AF61, "Battle Ace (J) (SGX)", GG_GAMEDB_SGX_REQUIRED},
+    { 0xB486A8ED, "Daimakaimura (J) (SGX)", GG_GAMEDB_SGX_REQUIRED},
+    { 0x1F041166, "Madouou Granzort (J) (SGX)", GG_GAMEDB_SGX_REQUIRED},
+
+    // OPTIONAL SGX
+    { 0xBEBFE042, "Darius Plus (J) (SGX)", GG_GAMEDB_SGX_OPTIONAL},
+
+    // SF2 MAPPER
+    { 0xD15CB6BB, "Street Fighter II' - Champion Edition (J)", GG_GAMEDB_SF2_MAPPER},
+
     {0, 0, GG_GAMEDB_NONE}
 };