GB Memory: Fix OAM DMA from top 8 kB

libretro · Jun 17, 2020 · 0234cb0 · 0234cb0
1 parent d2f84e6
commit 0234cb0
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Showing 5 changed files with 4 additions and 4 deletions.
diff --git a/CHANGES b/CHANGES
@@ -1,5 +1,6 @@
 0.8.3: (Future)
 Emulation fixes:
+ - GB Memory: Fix OAM DMA from top 8 kB
  - GB MBC: Fix MBC1 RAM enable bit selection
  - GB MBC: Fix MBC2 bit selection
 

diff --git a/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-dmgABCmgbS/baseline_0000.png b/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-dmgABCmgbS/baseline_0000.png
diff --git a/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-dmgABCmgbS/manifest.yml b/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-dmgABCmgbS/manifest.yml
diff --git a/src/gb/io.c b/src/gb/io.c
@@ -191,7 +191,7 @@ void GBIOReset(struct GB* gb) {
 	GBIOWrite(gb, REG_SCY, 0x00);
 	GBIOWrite(gb, REG_SCX, 0x00);
 	GBIOWrite(gb, REG_LYC, 0x00);
-	GBIOWrite(gb, REG_DMA, 0xFF);
+	gb->memory.io[REG_DMA] = 0xFF;
 	GBIOWrite(gb, REG_BGP, 0xFC);
 	if (gb->model < GB_MODEL_CGB) {
 		GBIOWrite(gb, REG_OBP0, 0xFF);

diff --git a/src/gb/memory.c b/src/gb/memory.c
@@ -519,8 +519,8 @@ uint8_t GBView8(struct SM83Core* cpu, uint16_t address, int segment) {
 }
 
 void GBMemoryDMA(struct GB* gb, uint16_t base) {
-	if (base > 0xF100) {
-		return;
+	if (base >= 0xE000) {
+		base &= 0xDFFF;
 	}
 	mTimingDeschedule(&gb->timing, &gb->memory.dmaEvent);
 	mTimingSchedule(&gb->timing, &gb->memory.dmaEvent, 8);