From 4184e82d8cd61fff7399272ae1fcca3c59712f11 Mon Sep 17 00:00:00 2001
From: slack <slack@codemaniacs.com>
Date: Mon, 14 Jul 2008 02:23:54 +0200
Subject: [PATCH] DMA. First steps

---
 GBMemory.cc | 17 +++++++++++----
 GBMemory.h  |  6 +++---
 GBVideo.cc  | 61 ++++++-----------------------------------------------
 GBVideo.h   |  4 ++++
 4 files changed, 26 insertions(+), 62 deletions(-)

diff --git a/GBMemory.cc b/GBMemory.cc
index ebd1b5e..dc2cba3 100644
--- a/GBMemory.cc
+++ b/GBMemory.cc
@@ -6,7 +6,7 @@
 #include <sstream>
 #include <iomanip>
 	
-void GBMemory::write(int addr, u8 value)
+void GBMemory::write(u16 addr, u8 value)
 {
 	if (addr < 0x8000)      mbc->write(addr, value);
 	else if (addr < 0xA000) core->video.write_VRAM(addr, value);
@@ -16,9 +16,18 @@ void GBMemory::write(int addr, u8 value)
 	else if (addr < 0xFEA0) core->video.write_OAM (addr, value);
 	else if (addr >= 0xFF00) {
 		high[addr-0xFF00] = value;
-		if (addr == DIV) {
+		if (addr == DIV) 
+		{
 			high[I_DIV] = 0;
 		}
+		/*
+		else if (addr == DMA)
+		{
+			u16 dma_src = value << 8;
+			logger.warning("OAM DMA transfer from 0x", std::hex, std::setfill('0'), dma_src, " requested");
+			core->video.DMA_OAM(dma_src);
+		}
+		*/
 	}
 	else {
 		std::ostringstream errmsg;
@@ -30,7 +39,7 @@ void GBMemory::write(int addr, u8 value)
 }
 
 
-u8  GBMemory::read(int addr) const
+u8  GBMemory::read(u16 addr) const
 {
 	if (addr < 0x8000)      return mbc->read(addr);
 	else if (addr < 0xA000) return core->video.read_VRAM(addr);
@@ -49,7 +58,7 @@ u8  GBMemory::read(int addr) const
 	}
 }
 
-u16 GBMemory::read16(int addr) const
+u16 GBMemory::read16(u16 addr) const
 {
 	if (addr < 0x8000)      return mbc->read16(addr);
 	else if (addr < 0xA000) return core->video.read16_VRAM(addr);
diff --git a/GBMemory.h b/GBMemory.h
index 14fa201..6e27bd4 100644
--- a/GBMemory.h
+++ b/GBMemory.h
@@ -36,9 +36,9 @@ class GBMemory
 	void init(MBC *mbc) { this->mbc = mbc; }
 
 
-	u8   read(int addr) const;
-	u16  read16(int addr) const;
-	void write(int addr, u8 value);
+	u8   read  (u16 addr) const;
+	u16  read16(u16 addr) const;
+	void write (u16 addr, u8 value);
 	
 	public:
 	static const u16 DIV  = 0xFF04; // Divider register     (R/W)
diff --git a/GBVideo.cc b/GBVideo.cc
index ac11a1a..ea81429 100644
--- a/GBVideo.cc
+++ b/GBVideo.cc
@@ -8,11 +8,11 @@
 
 
 GBVideo::GBVideo(GameBoy *core):
+	OAM(),
 	display(0),
 	core(core),
 	cur_window_line(0),
 	mode(2),
-	OAM(),
 	OAM_BUSY(false),
 	VRAM_BUSY(false),
 	frames_rendered(0),
@@ -51,63 +51,14 @@ void GBVideo::reset()
 	cycles_until_next_update = 0;
 }
 
-#if 0
-u8   GBVideo::read_VRAM (int addr) const
-{
-	//int STAT = core->memory.high[GBMemory::I_STAT];
-	//if ((STAT & 3) == 3)
-	//	return 0xFF; // VRAM access disabled
-	//else
-		return VRAM[addr-VRAM_BASE];
-}
-
-u8   GBVideo::read_OAM  (int addr) const
-{
-	//int STAT = core->memory.high[GBMemory::I_STAT];
-	//if ((STAT & 3) >= 2)
-	//	return 0xFF; // OAM access disabled
-	//else
-		return OAM.raw[addr-OAM_BASE];
-}
-
-u16   GBVideo::read16_VRAM (int addr) const
-{
-	//int STAT = core->memory.high[GBMemory::I_STAT];
-	//if ((STAT & 3) == 3)
-	//	return 0xFF; // VRAM access disabled
-	//else
-		return VRAM[addr-VRAM_BASE]+(VRAM[addr-VRAM_BASE+1] << 8);
-}
-
-u16   GBVideo::read16_OAM  (int addr) const
-{
-	//int STAT = core->memory.high[GBMemory::I_STAT];
-	//if ((STAT & 3) >= 2)
-	//	return 0xFF; // OAM access disabled
-	//else
-		return OAM.raw[addr-OAM_BASE]+(OAM.raw[addr-OAM_BASE+1] << 8);
-}
-
-void GBVideo::write_VRAM(int addr, u8 value)
-{
-	//int STAT = core->memory.high[GBMemory::I_STAT];
-	//if ((STAT & 3) == 3)
-	//	return; // VRAM access disabled
-	//else
-		VRAM[addr-VRAM_BASE] = value;
-}
-
-void GBVideo::write_OAM (int addr, u8 value)
+void GBVideo::DMA_OAM (const u16 src)
 {
-	//int STAT = core->memory.high[GBMemory::I_STAT];
-	//if ((STAT & 3) >= 2)
-	//	return; // OAM access disabled
-	//else
-		OAM.raw[addr-OAM_BASE] = value;
+	for (u16 i=0; i<160; i++)
+	{
+		OAM.raw[i] = core->memory.read(src+i);
+	}
 }
 
-#endif
-
 u32 GBVideo::update()
 {
 	//Mode 0 is present between 201-207 clks, 2 about 77-83 clks, and 3
diff --git a/GBVideo.h b/GBVideo.h
index 6047131..ac9f265 100644
--- a/GBVideo.h
+++ b/GBVideo.h
@@ -104,6 +104,10 @@ class GBVideo
 		if (!OAM_BUSY) OAM.raw[addr-OAM_BASE] = value;
 	}
 
+
+	// Write the whole OAM area via DMA
+	void DMA_OAM (const u16 src);
+
 	// drawing control
 	void draw();
 	u32 update();
-- 
2.34.1