mdec: hack: added MDECout chopped transfer support

Fixes Final Fantasy IX boot

src/device/dma/dma1_channel.cpp

@@ -7,4 +7,6 @@ DMA1Channel::DMA1Channel(Channel channel, System* sys, mdec::MDEC* mdec) : DMACh
 uint32_t DMA1Channel::readDevice() { return mdec->read(0); }
 
 bool DMA1Channel::dataRequest() { return mdec->dataOutRequest(); }
+
+bool DMA1Channel::hack_supportChoppedTransfer() const { return true; }
 }  // namespace device::dma

src/device/dma/dma1_channel.h

@@ -13,6 +13,7 @@ class DMA1Channel : public DMAChannel {
 
    protected:
     bool dataRequest() override;
+    bool hack_supportChoppedTransfer() const override;
 
    public:
     DMA1Channel(Channel channel, System* sys, mdec::MDEC* mdec);

src/device/dma/dma_channel.cpp

@@ -94,6 +94,8 @@ void DMAChannel::syncBlockTransfer() {
         canLog = false;
     }
 
+hack_transferLoop:
+
     // TODO: DREQ DACK for MDEC
     // TODO: Execute sync with chopping
     if (control.direction == CHCR::Direction::toRam) {
@@ -112,6 +114,9 @@ void DMAChannel::syncBlockTransfer() {
         irqFlag = true;
         control.enabled = CHCR::Enabled::completed;
     }
+    if (!hack_supportChoppedTransfer() && count.syncMode1.blockCount > 0) {
+        goto hack_transferLoop;
+    }
 }
 
 void DMAChannel::linkedListTransfer() {

src/device/dma/dma_channel.h

@@ -99,6 +99,7 @@ class DMAChannel {
 
     // DACK/DREQ
     virtual bool dataRequest() { return true; }
+    virtual bool hack_supportChoppedTransfer() const { return false; }
 
    public:
     bool irqFlag = false;

src/device/mdec/mdec.cpp

@@ -28,6 +28,9 @@ uint32_t MDEC::read(uint32_t address) {
         // 2:  b g r B
         // 3:    B G R  <- cycle continues
 
+        if (output.empty() || outputPtr >= output.size()) {
+            return 0;
+        }
         uint32_t data = 0;
         if (status.colorDepth == Status::ColorDepth::bit_24) {
             if (part == 0)
@@ -55,15 +58,15 @@ uint32_t MDEC::read(uint32_t address) {
         }
 
         if (outputPtr >= output.size()) {
-            outputPtr = 0;
+            output.clear();
         }
         return data;
     }
     if (address >= 4 && address < 8) {
         // TODO: Handle fifo bits
-        status.dataOutFifoEmpty = outputPtr >= output.size();
-        status.dataInFifoFull = 0;
-        status.commandBusy = 0;
+        status.dataOutFifoEmpty = output.empty();
+        status.dataInFifoFull = !input.empty();
+        status.commandBusy = !output.empty();
         return status._reg;
     }
 
@@ -138,6 +141,7 @@ void MDEC::write(uint32_t address, uint32_t data) {
                     if (paramCount == 1) {
                         // TODO: Pass macroblock, not raw pointer
                         decodeMacroblocks();
+                        input.clear();
                     }
 
                     break;
@@ -182,11 +186,11 @@ void MDEC::write(uint32_t address, uint32_t data) {
         return;
     }
     if (address >= 4 && address < 8) {
-        _control._reg = data;
+        control._reg = data;
 
-        if (_control.getBit(31)) reset();
-        status.dataInRequest = _control.getBit(28);
-        status.dataOutRequest = _control.getBit(27);
+        if (control.reset) reset();
+        status.dataInRequest = control.enableDataIn;
+        status.dataOutRequest = control.enableDataOut;
         return;
     }
 

src/device/mdec/mdec.h

@@ -41,12 +41,24 @@ class MDEC {
 
         Status() : _reg(0) {}
     };
+    union Control {
+        struct {
+            uint32_t : 29;
+            uint32_t enableDataOut : 1;  // Enables DMA1 and DataOut Request status bit
+            uint32_t enableDataIn : 1;   // Enables DMA0 and DataIn Request status bit
+            uint32_t reset : 1;
+        };
+        uint32_t _reg;
+        uint8_t _byte[4];
+
+        Control() : _reg(0) {}
+    };
 
     int verbose;
     Command command;
     Reg32 data;
     Status status;
-    Reg32 _control;
+    Control control;
 
     Commands cmd;
     std::array<uint8_t, 64> luminanceQuantTable;
@@ -75,10 +87,12 @@ class MDEC {
     uint32_t read(uint32_t address);
     void handleCommand(uint8_t cmd, uint32_t data);
     void write(uint32_t address, uint32_t data);
+    bool dataInRequest() const { return status.dataInRequest && output.empty(); }
+    bool dataOutRequest() const { return status.dataOutRequest && !output.empty(); }
 
     template <class Archive>
     void serialize(Archive& ar) {
-        ar(command._reg, data, status._reg, _control, cmd);
+        ar(command._reg, data, status._reg, control._reg, cmd);
         ar(luminanceQuantTable, colorQuantTable, idctTable);
         ar(color, paramCount, cnt);
         ar(input, output, outputPtr);