From 91dd493f954ea2c109e18fc0eb647f5cd7d9217f Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Tue, 16 Jun 2020 23:06:32 -0700
Subject: [PATCH] GB Memory: Fix OAM DMA from top 8 kB

---
 CHANGES                                           |   1 +
 .../oam_dma/sources-GS/baseline_0000.png          | Bin 0 -> 528 bytes
 .../acceptance/oam_dma/sources-GS/config.ini      |   2 --
 src/gb/io.c                                       |   2 +-
 src/gb/memory.c                                   |   4 ++--
 5 files changed, 4 insertions(+), 5 deletions(-)
 create mode 100644 cinema/gb/mooneye-gb/acceptance/oam_dma/sources-GS/baseline_0000.png
 delete mode 100644 cinema/gb/mooneye-gb/acceptance/oam_dma/sources-GS/config.ini

diff --git a/CHANGES b/CHANGES
index 86ea3ef60..006db1256 100644
--- a/CHANGES
+++ b/CHANGES
@@ -6,6 +6,7 @@ Emulation fixes:
  - ARM: Fix ALU reading PC after shifting
  - ARM: Fix STR storing PC after address calculation
  - GB: Partially fix timing for skipped BIOS
+ - GB Memory: Fix OAM DMA from top 8 kB
  - GB MBC: Fix MBC1 mode changing behavior
  - 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-GS/baseline_0000.png b/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-GS/baseline_0000.png
new file mode 100644
index 0000000000000000000000000000000000000000..f9e5e47b50a4d548ddbc988a8e76364d30f505cf
GIT binary patch
literal 528
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z<;Va1cWgxt&B%VfEU&=!xnok3TT$lH;@jICuivi!&oIyXfkoqEmOfz%KM+GNxySPP
z*F*Dd<=5Z6-dB81|M;InsWNlk%!+)xc<Jk(w<pip9`e0z`sA(t&#O<jZVkU5|2}8&
zJLfs9a_r^r4UcWhjSsu?{5^m17Jd7#z7Hmc{Ju1K-R9+WKfNuv_vl^zTGreDui^Tu
z-bA~+!oL&U@AAjZeBAw6Mn=70&VfRv<D8=m?1Au|?;2;WuxQJTNKj0By85}Sb4q9e
E0Q;uho&W#<

literal 0
HcmV?d00001

diff --git a/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-GS/config.ini b/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-GS/config.ini
deleted file mode 100644
index 7ddee425b..000000000
--- a/cinema/gb/mooneye-gb/acceptance/oam_dma/sources-GS/config.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[testinfo]
-fail=1
diff --git a/src/gb/io.c b/src/gb/io.c
index 134454e12..45b358146 100644
--- a/src/gb/io.c
+++ b/src/gb/io.c
@@ -193,7 +193,7 @@ 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
index 36d083df0..b070ff601 100644
--- 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);