Add support for 768Kbit SRAM save type

Fixes a Segfault when loading Dezaemon 3D.

  * Unfortunately, Dezaemon 3D does not actually work yet. It appears to
    fail the SRAM test, which still needs further investigation.

Adds an option alias for sram256k to disambiguate with new sram768k option.

cen64.c

@@ -140,8 +140,18 @@ int cen64_main(int argc, const char **argv) {
         break;
       case CART_DB_SAVE_TYPE_SRAM_256KBIT:
         if (options.sram_path == NULL) {
-          printf("Warning: cart saves to SRAM, but none specified (see -sram)\n");
+          printf("Warning: cart saves to 256kbit SRAM, but none specified (see -sram256k)\n");
           open_save_file(NULL, 0x8000, &sram, NULL);
+        } else if (options.sram_size != 0x8000) {
+          printf("Warning: cart saves to 256kbit SRAM, but different size specified (see -sram256k)\n");
+        }
+        break;
+      case CART_DB_SAVE_TYPE_SRAM_768KBIT:
+        if (options.sram_path == NULL) {
+          printf("Warning: cart saves to 768kbit SRAM, but none specified (see -sram768k)\n");
+          open_save_file(NULL, 0x18000, &sram, NULL);
+        } else if (options.sram_size != 0x18000) {
+          printf("Warning: cart saves to 768kbit SRAM, but different size specified (see -sram768k)\n");
         }
         break;
     }
@@ -159,7 +169,7 @@ int cen64_main(int argc, const char **argv) {
   }
 
   if (options.sram_path != NULL &&
-      open_save_file(options.sram_path, 0x8000, &sram, NULL)) {
+      open_save_file(options.sram_path, options.sram_size, &sram, NULL)) {
     cen64_alloc_cleanup();
     return EXIT_FAILURE;
   }

device/cart_db.c

@@ -18,6 +18,7 @@
 
 static const struct cart_db_entry cart_db_table[] = {
 
+  {"CDZ", "J",        CART_DB_SAVE_TYPE_SRAM_768KBIT,  "Dezaemon 3D"},
   {"CFZ", "EJ",       CART_DB_SAVE_TYPE_SRAM_256KBIT,  "F-Zero X (NTSC)"},
   {"CLB", "EJ",       CART_DB_SAVE_TYPE_EEPROM_4KBIT,  "Mario Party (NTSC)"},
   {"CP2", "J",        CART_DB_SAVE_TYPE_FLASH_1MBIT,   "Pokemon Stadium 2 (Japan)"},

device/cart_db.h

@@ -16,6 +16,7 @@ enum cart_db_save_type {
   CART_DB_SAVE_TYPE_EEPROM_16KBIT,
   CART_DB_SAVE_TYPE_FLASH_1MBIT,
   CART_DB_SAVE_TYPE_SRAM_256KBIT,
+  CART_DB_SAVE_TYPE_SRAM_768KBIT,
 };
 
 struct cart_db_entry {

device/options.c

@@ -23,6 +23,7 @@ const struct cen64_options default_cen64_options = {
   NULL, // eeprom_path
   0,    // eeprom_size
   NULL, // sram_path
+  0,    // sram_size
   NULL, // flashram_path
   0,    // is_viewer_present
   NULL, // controller
@@ -122,6 +123,27 @@ int parse_options(struct cen64_options *options, int argc, const char *argv[]) {
       }
 
       options->sram_path = argv[++i];
+      options->sram_size = 0x8000;
+    }
+
+    else if (!strcmp(argv[i], "-sram256k")) {
+      if ((i + 1) >= (argc - 1)) {
+        printf("-sram256k requires a path to the save file.\n\n");
+        return 1;
+      }
+
+      options->sram_path = argv[++i];
+      options->sram_size = 0x8000;
+    }
+
+    else if (!strcmp(argv[i], "-sram768k")) {
+      if ((i + 1) >= (argc - 1)) {
+        printf("-sram768k requires a path to the save file.\n\n");
+        return 1;
+      }
+
+      options->sram_path = argv[++i];
+      options->sram_size = 0x18000;
     }
 
     else if (!strcmp(argv[i], "-flash")) {
@@ -279,7 +301,9 @@ void print_command_line_usage(const char *invokation_string) {
       "Save Options:\n"
       "  -eep4k <path>              : Path to 4 kbit EEPROM save.\n"
       "  -eep16k <path>             : Path to 16 kbit EEPROM save.\n"
-      "  -sram <path>               : Path to SRAM save.\n"
+      "  -sram <path>               : Path to 256 kbit SRAM save (alias of -sram256k).\n"
+      "  -sram256k <path>           : Path to 256 kbit SRAM save.\n"
+      "  -sram768k <path>           : Path to 768 kbit SRAM save.\n"
       "  -flash <path>              : Path to FlashRAM save.\n"
       "    For mempak see controller options.\n"
 

device/options.h

@@ -22,6 +22,7 @@ struct cen64_options {
   const char *eeprom_path;
   size_t eeprom_size;
   const char *sram_path;
+  size_t sram_size;
   const char *flashram_path;
   int is_viewer_present;
 

pi/controller.c

@@ -57,14 +57,17 @@ static int pi_dma_read(struct pi_controller *pi) {
   if (source & 0x7)
     length -= source & 0x7;
 
-  // SRAM and FlashRAM
+  // Cartridge Domain 2 Address 2
-  if (dest >= 0x08000000 && dest < 0x08010000) {
+  if (dest >= 0x08000000 && dest < 0x10000000) {
-    uint32_t addr = dest & 0x00FFFFF;
-
     // SRAM
-    if (pi->sram->ptr != NULL && addr + length <= 0x8000)
+    if (pi->sram->ptr != NULL) {
-      memcpy((uint8_t *) (pi->sram->ptr) + addr, pi->bus->ri->ram + source, length);
+      // SRAM bank selection bits are [19:18]
-
+      uint32_t sram_bank = (dest >> 18) & 3;
+      // SRAM bank capacity is 256Kbits (0x8000 bytes)
+      uint32_t sram_offset = (sram_bank * 0x8000) + (dest & 0x7FFF);
+      if (sram_offset + length <= pi->sram->size)
+        memcpy((uint8_t *) (pi->sram->ptr) + sram_offset, pi->bus->ri->ram + source, length);
+    }
     // FlashRAM: Save the RDRAM destination address. Writing happens
     // after the system sends the flash write command (handled in
     // write_flashram)
@@ -111,23 +114,28 @@ static int pi_dma_write(struct pi_controller *pi) {
   else if ((source & 0x05000000) == 0x05000000)
     dd_dma_write(pi->bus->dd, source, dest, length);
 
-  // SRAM and FlashRAM
+  // Cartridge Domain 2 Address 2
-  else if (source >= 0x08000000 && source < 0x08010000) {
+  else if (source >= 0x08000000 && source < 0x10000000) {
-    uint32_t addr = source & 0x00FFFFF;
+    // SRAM
-
+    if (pi->sram->ptr != NULL) {
-    if (pi->sram->ptr != NULL && addr + length <= 0x8000)
+      // SRAM bank selection bits are [19:18]
-      memcpy(pi->bus->ri->ram + dest, (const uint8_t *) (pi->sram->ptr) + addr, length);
+      uint32_t sram_bank = (source >> 18) & 3;
-
+      // SRAM bank capacity is 256Kbits (0x8000 bytes)
+      uint32_t sram_offset = (sram_bank * 0x8000) + (source & 0x7FFF);
+      if (sram_offset + length <= pi->sram->size)
+        memcpy(pi->bus->ri->ram + dest, (const uint8_t *) (pi->sram->ptr) + sram_offset, length);
+    }
+    // FlashRAM
     else if (pi->flashram.data != NULL) {
-      // SRAM
+      uint32_t flashram_offset = source & 0x1FFFF;
+      // FlashRAM status
       if (pi->flashram.mode == FLASHRAM_STATUS) {
         uint64_t status = htonll(pi->flashram.status);
         memcpy(pi->bus->ri->ram + dest, &status, 8);
       }
-
+      // FlashRAM read
-      // FlashRAM
       else if (pi->flashram.mode == FLASHRAM_READ)
-        memcpy(pi->bus->ri->ram + dest, pi->flashram.data + addr * 2, length);
+        memcpy(pi->bus->ri->ram + dest, pi->flashram.data + flashram_offset * 2, length);
     }
   }