Merge pull request #246 from nba-emu/feature/eeprom-size-detection

EEPROM: automatically detect save size (closes #219)
nba-emu · Aug 13, 2022 · 3a43a77 · 3a43a77
2 parents bee187f + a81097f
commit 3a43a77
Show file tree

Hide file tree

Showing 8 changed files with 78 additions and 34 deletions.
diff --git a/src/nba/include/nba/config.hpp b/src/nba/include/nba/config.hpp
@@ -26,7 +26,8 @@ struct Config {
     FLASH_64,
     FLASH_128,
     EEPROM_4,
-    EEPROM_64
+    EEPROM_64,
+    EEPROM_DETECT // for internal use
   };
 
   struct Audio {

diff --git a/src/nba/include/nba/rom/backup/eeprom.hpp b/src/nba/include/nba/rom/backup/eeprom.hpp
@@ -16,7 +16,8 @@ namespace nba {
 struct EEPROM : Backup {
   enum Size {
     SIZE_4K  = 0,
-    SIZE_64K = 1
+    SIZE_64K = 1,
+    DETECT = 2
   };
 
   EEPROM(std::string const& save_path, Size size_hint);
@@ -28,6 +29,8 @@ struct EEPROM : Backup {
   void LoadState(SaveState const& state) final;
   void CopyState(SaveState& state) final;
 
+  void SetSizeHint(Size size);
+
 private:
   enum State {
     STATE_ACCEPT_COMMAND = 1 << 0,
@@ -50,6 +53,8 @@ struct EEPROM : Backup {
   int address;
   u64 serial_buffer;
   int transmitted_bits;
+
+  bool detect_size;
 };
 
 } // namespace nba
diff --git a/src/nba/include/nba/rom/rom.hpp b/src/nba/include/nba/rom/rom.hpp
@@ -106,6 +106,12 @@ struct ROM {
     }
   }
 
+  void SetEEPROMSizeHint(EEPROM::Size size) {
+    if (backup_eeprom) {
+      ((EEPROM*)backup_eeprom.get())->SetSizeHint(size);
+    }
+  }
+
   auto ALWAYS_INLINE ReadROM16(u32 address) -> u16 {
     address &= 0x01FF'FFFE;
 

diff --git a/src/nba/src/hw/dma/dma.cpp b/src/nba/src/hw/dma/dma.cpp
@@ -151,13 +151,13 @@ bool DMA::HasVideoTransferDMA() {
 }
 
 void DMA::Run() {
-  memory.Idle();
+  bus.Idle();
 
   do {
     RunChannel();
   } while (IsRunning());
 
-  memory.Idle();
+  bus.Idle();
 }
 
 void DMA::RunChannel() {
@@ -203,7 +203,7 @@ void DMA::RunChannel() {
       u16 value;
 
       if (likely(src_addr >= 0x02000000)) {
-        value = memory.ReadHalf(src_addr, access_src);
+        value = bus.ReadHalf(src_addr, access_src);
         channel.latch.bus = (value << 16) | value;
         latch = channel.latch.bus;
       } else {
@@ -212,19 +212,19 @@ void DMA::RunChannel() {
         } else {
           value = channel.latch.bus;
         }
-        memory.Idle();
+        bus.Idle();
       }
 
-      memory.WriteHalf(dst_addr, value, access_dst);
+      bus.WriteHalf(dst_addr, value, access_dst);
     } else {
       if (likely(src_addr >= 0x02000000)) {
-        channel.latch.bus = memory.ReadWord(src_addr, access_src);
+        channel.latch.bus = bus.ReadWord(src_addr, access_src);
         latch = channel.latch.bus;
       } else {
-        memory.Idle();
+        bus.Idle();
       }
 
-      memory.WriteWord(dst_addr, channel.latch.bus, access_dst);
+      bus.WriteWord(dst_addr, channel.latch.bus, access_dst);
     }
 
     channel.latch.src_addr += src_modify;
@@ -374,6 +374,21 @@ void DMA::OnChannelWritten(Channel& channel, bool enable_old) {
         } else {
           AddChannelToDMASet(channel);
         }
+
+        /* Try to auto-detect EEPROM size from the first EEPROM DMA transfer,
+         * since we cannot always determine the size at load time.
+         */
+        if (channel.dst_addr >= 0x0D000000) {
+          int length = channel.length;
+
+          if (length == 9 || length == 73) {
+            bus.memory.rom.SetEEPROMSizeHint(EEPROM::Size::SIZE_4K);
+          }
+
+          if (length == 17 || length == 81) {
+            bus.memory.rom.SetEEPROMSizeHint(EEPROM::Size::SIZE_64K);
+          }
+        }
       }
     } else {
       // DMA enable bit: 1 -> 1 (remains set)

diff --git a/src/nba/src/hw/dma/dma.hpp b/src/nba/src/hw/dma/dma.hpp
@@ -19,8 +19,8 @@ namespace nba::core {
 struct Bus;
 
 struct DMA {
-  DMA(Bus& memory, IRQ& irq, Scheduler& scheduler)
-      : memory(memory)
+  DMA(Bus& bus, IRQ& irq, Scheduler& scheduler)
+      : bus(bus)
       , irq(irq)
       , scheduler(scheduler) {
     Reset();
@@ -117,7 +117,7 @@ struct DMA {
   void RemoveChannelFromDMASets(Channel& channel);
   void RunChannel();
 
-  Bus& memory;
+  Bus& bus;
   IRQ& irq;
   Scheduler& scheduler;
 

diff --git a/src/nba/src/hw/rom/backup/eeprom.cpp b/src/nba/src/hw/rom/backup/eeprom.cpp
@@ -25,9 +25,17 @@ void EEPROM::Reset() {
   address = 0;
   ResetSerialBuffer();
 
+  if (size == DETECT) {
+    size = SIZE_64K; // default to 8 KiB size
+    detect_size = true;
+  } else {
+    detect_size = false;
+  }
+
   int bytes = g_save_size[size];
 
-  file = BackupFile::OpenOrCreate(save_path, { 512, 8192 }, bytes);
+  file = BackupFile::OpenOrCreate(save_path, {512, 8192}, bytes);
+
   if (bytes == g_save_size[0]) {
     size = SIZE_4K;
   } else {
@@ -127,4 +135,17 @@ void EEPROM::Write(u32 address, u8 value) {
   }
 }
 
+void EEPROM::SetSizeHint(Size size) {
+  if (detect_size) {
+    int bytes = g_save_size[size];
+
+    this->size = size;
+    detect_size = false;
+
+    if (file->Size() != bytes) {
+      file = BackupFile::OpenOrCreate(save_path, {(size_t)bytes}, bytes);
+    }
+  }
+}
+
 } // namespace nba
diff --git a/src/platform/core/src/loader/rom.cpp b/src/platform/core/src/loader/rom.cpp
@@ -192,11 +192,11 @@ auto ROMLoader::GetBackupType(
   std::vector<u8>& file_data
 ) -> BackupType {
   static constexpr std::pair<std::string_view, BackupType> signatures[6] {
-    { "EEPROM_V",   BackupType::EEPROM_64 },
-    { "SRAM_V",     BackupType::SRAM      },
-    { "SRAM_F_V",   BackupType::SRAM      },
-    { "FLASH_V",    BackupType::FLASH_64  },
-    { "FLASH512_V", BackupType::FLASH_64  },
+    { "EEPROM_V",   BackupType::EEPROM_DETECT },
+    { "SRAM_V",     BackupType::SRAM },
+    { "SRAM_F_V",   BackupType::SRAM },
+    { "FLASH_V",    BackupType::FLASH_64 },
+    { "FLASH512_V", BackupType::FLASH_64 },
     { "FLASH1M_V",  BackupType::FLASH_128 }
   };
 
@@ -219,21 +219,12 @@ auto ROMLoader::CreateBackup(
   BackupType backup_type
 ) -> std::unique_ptr<Backup> {
   switch (backup_type) {
-    case BackupType::SRAM: {
-      return std::make_unique<SRAM>(save_path);
-    }
-    case BackupType::FLASH_64: {
-      return std::make_unique<FLASH>(save_path, FLASH::SIZE_64K);
-    }
-    case BackupType::FLASH_128: {
-      return std::make_unique<FLASH>(save_path, FLASH::SIZE_128K);
-    }
-    case BackupType::EEPROM_4: {
-      return std::make_unique<EEPROM>(save_path, EEPROM::SIZE_4K);
-    }
-    case BackupType::EEPROM_64: {
-      return std::make_unique<EEPROM>(save_path, EEPROM::SIZE_64K);
-    }
+    case BackupType::SRAM:      return std::make_unique<SRAM>(save_path);
+    case BackupType::FLASH_64:  return std::make_unique<FLASH>(save_path, FLASH::SIZE_64K);
+    case BackupType::FLASH_128: return std::make_unique<FLASH>(save_path, FLASH::SIZE_128K);
+    case BackupType::EEPROM_4:  return std::make_unique<EEPROM>(save_path, EEPROM::SIZE_4K);
+    case BackupType::EEPROM_64: return std::make_unique<EEPROM>(save_path, EEPROM::SIZE_64K);
+    case BackupType::EEPROM_DETECT: return std::make_unique<EEPROM>(save_path, EEPROM::DETECT);
   }
 
   return {};

diff --git a/src/platform/qt/src/widget/main_window.cpp b/src/platform/qt/src/widget/main_window.cpp
@@ -467,6 +467,11 @@ void MainWindow::PromptUserForReset() {
     box.setDefaultButton(QMessageBox::No);
 
     if (box.exec() == QMessageBox::Yes) {
+      // Reload the ROM in case its config (e.g. save type or GPIO) has changed:
+      if (game_loaded) {
+        LoadROM(game_path);
+      }
+
       Reset();
     }
   }