Trying to setup writeback and add basic secondary command execution.

src/xenia/gpu/ring_buffer_worker.cc

@@ -43,6 +43,17 @@ void RingBufferWorker::Initialize(uint32_t ptr, uint32_t page_count) {
   xe_thread_start(thread_);
 }
 
+void RingBufferWorker::EnableReadPointerWriteBack(uint32_t ptr,
+                                                  uint32_t block_size) {
+  // CP_RB_RPTR_ADDR Ring Buffer Read Pointer Address 0x70C
+  // ptr = RB_RPTR_ADDR, pointer to write back the address to.
+  read_ptr_writeback_ptr_ = (primary_buffer_ptr_ & ~0x1FFFFFFF) + ptr;
+  // CP_RB_CNTL Ring Buffer Control 0x704
+  // block_size = RB_BLKSZ, number of quadwords read between updates of the
+  //              read pointer.
+  read_ptr_update_freq_ = (uint32_t)pow(2.0, (double)block_size) / 4;
+}
+
 void RingBufferWorker::UpdateWritePointer(uint32_t value) {
   write_ptr_index_ = value;
   SetEvent(write_ptr_index_event_);
@@ -74,22 +85,30 @@ void RingBufferWorker::ThreadStart() {
 
     while (true) {
       uint32_t command = READ_UINT32();
-      XELOGGPU("Command(%.8X)", command);
 
       switch (command) {
       case 0xC0114800:
-        // Init packet.
-        // Will have 18-19 ops after it. Maybe.
-        for (int n = 0; n < 18; n++) {
-          READ_UINT32();
+        {
+          // Init packet.
+          // Will have 18-19 ops after it. Maybe.
+          XELOGGPU("Command(%.8X): init packet", command);
+          for (int n = 0; n < 18; n++) {
+            READ_UINT32();
+          }
         }
         break;
       case 0xC0013F00:
-        // Kick segment.
-        uint32_t segment_ptr = READ_UINT32();
-        uint32_t length = READ_UINT32();
-        XELOGGPU("Command(%.8X): kick segment %.8X (%db)",
-                 command, segment_ptr, length);
+        {
+          // Kick segment.
+          uint32_t segment_ptr = READ_UINT32();
+          uint32_t length = READ_UINT32();
+          XELOGGPU("Command(%.8X): kick segment %.8X (%db)",
+                   command, segment_ptr, length * 4);
+          ExecuteSegment(segment_ptr, length);
+        }
+        break;
+      default:
+        XELOGGPU("Command(%.8X): unknown primary buffer command", command);
         break;
       }
 
@@ -98,6 +117,26 @@ void RingBufferWorker::ThreadStart() {
       }
     }
 
+    // TODO(benvanik): use read_ptr_update_freq_ and only issue after moving
+    //     that many indices.
+    if (read_ptr_writeback_ptr_) {
+      XESETUINT32BE(p + read_ptr_writeback_ptr_, read_ptr_index_);
+    }
     SetEvent(read_ptr_index_event_);
   }
 }
+
+void RingBufferWorker::ExecuteSegment(uint32_t ptr, uint32_t length) {
+  uint8_t* p = xe_memory_addr(memory_);
+
+  // Adjust pointer base.
+  ptr += (primary_buffer_ptr_ & ~0x1FFFFFFF);
+
+  XELOGGPU("CommandList(%.8X): executing %d commands", ptr, length);
+
+  // Execute commands!
+  for (uint32_t n = 0; n < length; n++) {
+    uint32_t command = XEGETUINT32BE(p + ptr + n * 4);
+    XELOGGPU("  Command(%.8X)", command);
+  }
+}