add functionality to import savefiles

src/NDS.cpp

@@ -1124,6 +1124,11 @@ void MicInputFrame(s16* data, int samples)
     return SPI_TSC::MicInputFrame(data, samples);
 }
 
+int ImportSRAM(u8* data, u32 length)
+{
+    return NDSCart::ImportSRAM(data, length);
+}
+
 
 void Halt()
 {

src/NDS.h

@@ -211,6 +211,8 @@ void SetLidClosed(bool closed);
 
 void MicInputFrame(s16* data, int samples);
 
+int ImportSRAM(u8* data, u32 length);
+
 void ScheduleEvent(u32 id, bool periodic, s32 delay, void (*func)(u32), u32 param);
 void CancelEvent(u32 id);
 

src/NDSCart.cpp

@@ -1034,6 +1034,12 @@ void RelocateSave(const char* path, bool write)
     NDSCart_SRAM::RelocateSave(path, write);
 }
 
+int ImportSRAM(const u8* data, u32 length)
+{
+    memcpy(NDSCart_SRAM::SRAM, data, std::min(length, NDSCart_SRAM::SRAMLength));
+    return length - NDSCart_SRAM::SRAMLength;
+}
+
 void ResetCart()
 {
     // CHECKME: what if there is a transfer in progress?

src/NDSCart.h

@@ -48,6 +48,8 @@ void DecryptSecureArea(u8* out);
 bool LoadROM(const char* path, const char* sram, bool direct);
 void RelocateSave(const char* path, bool write);
 
+int ImportSRAM(const u8* data, u32 length);
+
 void ResetCart();
 
 void WriteROMCnt(u32 val);

src/frontend/FrontendUtil.h

@@ -100,6 +100,9 @@ bool SaveState(const char* filename);
 // undo the latest savestate load
 void UndoStateLoad();
 
+// imports savedata from an external file. Returns the difference between the filesize and the SRAM size
+int ImportSRAM(const char* filename);
+
 // enable or disable cheats
 void EnableCheats(bool enable);
 

src/frontend/Util_ROM.cpp

@@ -588,6 +588,21 @@ void UndoStateLoad()
     }
 }
 
+int ImportSRAM(const char* filename)
+{
+    FILE* file = fopen(filename, "rb");
+    fseek(file, 0, SEEK_END);
+    u32 size = ftell(file);
+    u8* importData = new u8[size];
+    rewind(file);
+    fread(importData, size, 1, file);
+    fclose(file);
+
+    int diff = NDS::ImportSRAM(importData, size);
+    delete[] importData;
+    return diff;
+}
+
 void EnableCheats(bool enable)
 {
     CheatsOn = enable;

src/frontend/qt_sdl/main.cpp

@@ -1052,6 +1052,9 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
         actUndoStateLoad->setShortcut(QKeySequence(Qt::Key_F12));
         connect(actUndoStateLoad, &QAction::triggered, this, &MainWindow::onUndoStateLoad);
 
+        actImportSavefile = menu->addAction("Import savefile");
+        connect(actImportSavefile, &QAction::triggered, this, &MainWindow::onImportSavefile);
+
         menu->addSeparator();
 
         actQuit = menu->addAction("Quit");
@@ -1220,6 +1223,7 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
         actLoadState[i]->setEnabled(false);
     }
     actUndoStateLoad->setEnabled(false);
+    actImportSavefile->setEnabled(false);
 
     actPause->setEnabled(false);
     actReset->setEnabled(false);
@@ -1618,6 +1622,41 @@ void MainWindow::onUndoStateLoad()
     OSD::AddMessage(0, "State load undone");
 }
 
+void MainWindow::onImportSavefile()
+{
+    if (!RunningSomething) return;
+
+    emuThread->emuPause();
+    QString path = QFileDialog::getOpenFileName(this,
+                                            "Select savefile",
+                                            Config::LastROMFolder,
+                                            "Savefiles (*.sav *.bin *.dsv);;Any file (*.*)");
+
+    if (!path.isEmpty())
+    {
+        if (QMessageBox::warning(this,
+                        "Emulation will be reset and data overwritten",
+                        "The emulation will be reset and the current savefile overwritten.",
+                        QMessageBox::Ok, QMessageBox::Cancel) == QMessageBox::Ok)
+        {
+            int res = Frontend::Reset();
+            if (res != Frontend::Load_OK)
+            {
+                QMessageBox::critical(this, "melonDS", "Reset failed\n" + loadErrorStr(res));
+            }
+            else
+            {
+                int diff = Frontend::ImportSRAM(path.toStdString().c_str());
+                if (diff > 0)
+                    OSD::AddMessage(0, "Trimmed savefile");
+                else if (diff < 0)
+                    OSD::AddMessage(0, "Savefile shorter than SRAM");
+            }
+        }
+    }
+    emuThread->emuUnpause();
+}
+
 void MainWindow::onQuit()
 {
     QApplication::quit();
@@ -1923,6 +1962,7 @@ void MainWindow::onEmuStart()
     actPause->setChecked(false);
     actReset->setEnabled(true);
     actStop->setEnabled(true);
+    actImportSavefile->setEnabled(true);
 
     actSetupCheats->setEnabled(true);
 }
@@ -1937,6 +1977,7 @@ void MainWindow::onEmuStop()
         actLoadState[i]->setEnabled(false);
     }
     actUndoStateLoad->setEnabled(false);
+    actImportSavefile->setEnabled(false);
 
     actPause->setEnabled(false);
     actReset->setEnabled(false);

src/frontend/qt_sdl/main.h

@@ -195,6 +195,7 @@ private slots:
     void onSaveState();
     void onLoadState();
     void onUndoStateLoad();
+    void onImportSavefile();
     void onQuit();
 
     void onPause(bool checked);
@@ -247,6 +248,7 @@ public:
     QAction* actSaveState[9];
     QAction* actLoadState[9];
     QAction* actUndoStateLoad;
+    QAction* actImportSavefile;
     QAction* actQuit;
 
     QAction* actPause;