Merge pull request #75 from negativeExponent/use_libretro_save_api

add optional support for backup saves using libretro api

gba_memory.c

@@ -367,40 +367,11 @@ u32 gbc_sound_update = 0;
 // If the GBC audio waveform is modified:
 u32 gbc_sound_wave_update = 0;
 
-typedef enum
-{
-  BACKUP_SRAM,
-  BACKUP_FLASH,
-  BACKUP_EEPROM,
-  BACKUP_NONE
-} backup_type_type;
-
-typedef enum
-{
-  SRAM_SIZE_32KB,
-  SRAM_SIZE_64KB
-} sram_size_type;
-
 // Keep it 32KB until the upper 64KB is accessed, then make it 64KB.
 
 backup_type_type backup_type = BACKUP_NONE;
 sram_size_type sram_size = SRAM_SIZE_32KB;
 
-typedef enum
-{
-  FLASH_BASE_MODE,
-  FLASH_ERASE_MODE,
-  FLASH_ID_MODE,
-  FLASH_WRITE_MODE,
-  FLASH_BANKSWITCH_MODE
-} flash_mode_type;
-
-typedef enum
-{
-  FLASH_SIZE_64KB,
-  FLASH_SIZE_128KB
-} flash_size_type;
-
 flash_mode_type flash_mode = FLASH_BASE_MODE;
 u32 flash_command_position = 0;
 u8 *flash_bank_ptr = gamepak_backup;
@@ -459,25 +430,6 @@ u8 read_backup(u32 address)
 // EEPROM is 512 bytes by default; it is autodetecte as 8KB if
 // 14bit address DMAs are made (this is done in the DMA handler).
 
-typedef enum
-{
-  EEPROM_512_BYTE,
-  EEPROM_8_KBYTE
-} eeprom_size_type;
-
-typedef enum
-{
-  EEPROM_BASE_MODE,
-  EEPROM_READ_MODE,
-  EEPROM_READ_HEADER_MODE,
-  EEPROM_ADDRESS_MODE,
-  EEPROM_WRITE_MODE,
-  EEPROM_WRITE_ADDRESS_MODE,
-  EEPROM_ADDRESS_FOOTER_MODE,
-  EEPROM_WRITE_FOOTER_MODE
-} eeprom_mode_type;
-
-
 eeprom_size_type eeprom_size = EEPROM_512_BYTE;
 eeprom_mode_type eeprom_mode = EEPROM_BASE_MODE;
 u32 eeprom_address_length;
@@ -2197,7 +2149,8 @@ u32 save_backup(char *name)
 
 void update_backup(void)
 {
-  save_backup(backup_filename);
+  if (!use_libretro_save_method)
+    save_backup(backup_filename);
 }
 
 #define CONFIG_FILENAME "game_config.txt"
@@ -2480,7 +2433,8 @@ u32 load_gamepak(const struct retro_game_info* info, const char *name)
    if (p)
       strcpy(p, ".sav");
 
-   load_backup(backup_filename);
+   if (!use_libretro_save_method)
+     load_backup(backup_filename);
 
    memcpy(gamepak_title, gamepak_rom + 0xA0, 12);
    memcpy(gamepak_code, gamepak_rom + 0xAC, 4);

gba_memory.h

@@ -21,6 +21,7 @@
 #define MEMORY_H
 
 #include "libretro.h"
+extern int use_libretro_save_method;
 
 typedef enum
 {
@@ -215,6 +216,62 @@ extern flash_device_id_type flash_device_id;
 extern const u8 *state_mem_read_ptr;
 extern u8 *state_mem_write_ptr;
 
+typedef enum
+{
+  BACKUP_SRAM,
+  BACKUP_FLASH,
+  BACKUP_EEPROM,
+  BACKUP_NONE
+} backup_type_type;
+
+typedef enum
+{
+  SRAM_SIZE_32KB,
+  SRAM_SIZE_64KB
+} sram_size_type;
+
+typedef enum
+{
+  FLASH_BASE_MODE,
+  FLASH_ERASE_MODE,
+  FLASH_ID_MODE,
+  FLASH_WRITE_MODE,
+  FLASH_BANKSWITCH_MODE
+} flash_mode_type;
+
+typedef enum
+{
+  FLASH_SIZE_64KB,
+  FLASH_SIZE_128KB
+} flash_size_type;
+
+
+extern backup_type_type backup_type;
+extern sram_size_type sram_size;
+extern flash_size_type flash_size;
+
+typedef enum
+{
+  EEPROM_512_BYTE,
+  EEPROM_8_KBYTE
+} eeprom_size_type;
+
+typedef enum
+{
+  EEPROM_BASE_MODE,
+  EEPROM_READ_MODE,
+  EEPROM_READ_HEADER_MODE,
+  EEPROM_ADDRESS_MODE,
+  EEPROM_WRITE_MODE,
+  EEPROM_WRITE_ADDRESS_MODE,
+  EEPROM_ADDRESS_FOOTER_MODE,
+  EEPROM_WRITE_FOOTER_MODE
+} eeprom_mode_type;
+
+extern eeprom_size_type eeprom_size;
+
+extern u8 gamepak_backup[1024 * 128];
+
 static inline void state_mem_write(const void* src, size_t size)
 {
   memcpy(state_mem_write_ptr, src, size);

libretro.c

@@ -8,6 +8,7 @@
 #include "libretro.h"
 #include "memmap.h"
 
+#include "gba_memory.h"
 
 #if defined(VITA) && defined(HAVE_DYNAREC)
 #include <psp2/kernel/sysmem.h>
@@ -73,6 +74,7 @@ struct retro_perf_callback perf_cb;
 static cothread_t main_thread;
 static cothread_t cpu_thread;
 int dynarec_enable;
+int use_libretro_save_method = 0;
 
 u32 idle_loop_target_pc = 0xFFFFFFFF;
 u32 iwram_stack_optimize = 1;
@@ -332,6 +334,7 @@ void retro_set_environment(retro_environment_t cb)
       { "gpsp_frameskip_type", "Frameskip type; off|manual|automatic" },
       { "gpsp_frameskip_value", "Frameskip value; 1|2|3|4|5|6|7|8|9" },
       { "gpsp_frameskip_variation", "Frameskip variation; uniform|random" },
+      { "gpsp_save_method", "Backup Save Method (Restart); gpSP|libretro" },
       { NULL, NULL },
    };
 
@@ -488,6 +491,19 @@ static void check_variables(int started_from_load)
       else if (!strcmp(var.value, "random"))
          random_skip = 1;
    }
+
+   if (started_from_load)
+   {
+      var.key = "gpsp_save_method";
+      var.value = NULL;
+      if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
+      {
+         if (!strcmp(var.value, "libretro"))
+            use_libretro_save_method = 1;
+         else
+            use_libretro_save_method = 0;
+      }
+   }
 }
 
 static void set_input_descriptors()
@@ -540,6 +556,7 @@ bool retro_load_game(const struct retro_game_info* info)
    if (!info)
       return false;
 
+   use_libretro_save_method = 0;
    check_variables(1);
    set_input_descriptors();
 
@@ -614,6 +631,7 @@ bool retro_load_game(const struct retro_game_info* info)
       info_msg("It is strongly recommended that you obtain the correct BIOS file.");
    }
 
+   memset(gamepak_backup, -1, sizeof(gamepak_backup));
    gamepak_filename[0] = 0;
    if (load_gamepak(info, info->path) != 0)
    {
@@ -630,7 +648,6 @@ bool retro_load_game(const struct retro_game_info* info)
    return true;
 }
 
-
 bool retro_load_game_special(unsigned game_type,
                              const struct retro_game_info* info, size_t num_info)
 {
@@ -650,43 +667,61 @@ unsigned retro_get_region(void)
 
 void* retro_get_memory_data(unsigned id)
 {
-   if ( id == RETRO_MEMORY_SYSTEM_RAM )
+   switch (id)
-      return ewram ;
+   {
-   //   switch (id)
+   case RETRO_MEMORY_SAVE_RAM:
-   //   {
+      if (use_libretro_save_method)
-   //   case RETRO_MEMORY_SAVE_RAM:
+         return gamepak_backup;
-   //      return gamepak_backup;
+      break;
-   //   }
+   default:
+      break;
+   }
 
    return 0;
 }
 
 size_t retro_get_memory_size(unsigned id)
 {
+   switch (id)
+   {
+   case RETRO_MEMORY_SAVE_RAM:
+      if (use_libretro_save_method)
+      {
+         switch(backup_type)
+         {
+         case BACKUP_SRAM:
+            if(sram_size == SRAM_SIZE_32KB)
+               return 0x8000;
+            else
+               return 0x10000;
+            break;
 
-   if ( id == RETRO_MEMORY_SYSTEM_RAM )
+         case BACKUP_FLASH:
-      return 1024 * 256 * 2 ;
+            if(flash_size == FLASH_SIZE_64KB)
-  //   switch (id)
+               return 0x10000;
-   //   {
+            else
-   //   case RETRO_MEMORY_SAVE_RAM:
+               return 0x20000;
-   //      switch(backup_type)
+            break;
-   //      {
-   //      case BACKUP_SRAM:
-   //         return sram_size;
 
-   //      case BACKUP_FLASH:
+         case BACKUP_EEPROM:
-   //         return flash_size;
+            if(eeprom_size == EEPROM_512_BYTE)
-
+               return 0x200;
-   //      case BACKUP_EEPROM:
+            else
-   //         return eeprom_size;
+               return 0x2000;
-
+            break;
-   //      case BACKUP_NONE:
+         // assume 128KB save, regardless if rom supports battery saves
-   //         return 0x0;
+         // this is needed because gba cannot provide initially the backup save size 
-
+         // until a few cycles has passed (unless provided by a database)
-   //      default:
+         case BACKUP_NONE:
-   //         return 0x8000;
+         default:
-   //      }
+            return (1024 * 128);
-   //   }
+            break;
+         }
+      }
+      break;
+   default:
+      break;
+   }
 
    return 0;
 }