From ba00cdfc024e495dc377f07d9ed6e5c57958de9c Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Thu, 30 May 2019 12:26:49 -0700
Subject: [PATCH] GBA Memory: Fix STM to VRAM (fixes #1430)

---
 CHANGES          |  1 +
 src/gba/memory.c | 52 ++++++++++++++++++++++++++++++------------------
 2 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/CHANGES b/CHANGES
index 84dbb27fa..3366a9ea9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -19,6 +19,7 @@ Emulation fixes:
  - GB Video: Fix window being enabled mid-scanline (fixes mgba.io/i/1328)
  - GB I/O: Filter IE top bits properly (fixes mgba.io/i/1329)
  - GBA Video: Fix wrapped sprite mosaic clamping (fixes mgba.io/i/1432)
+ - GBA Memory: Fix STM to VRAM (fixes mgba.io/i/1430)
 Other fixes:
  - Qt: Fix some Qt display driver race conditions
  - Core: Improved lockstep driver reliability (Le Hoang Quyen)
diff --git a/src/gba/memory.c b/src/gba/memory.c
index 3f037567c..62fa6fda9 100644
--- a/src/gba/memory.c
+++ b/src/gba/memory.c
@@ -396,9 +396,10 @@ static void GBASetActiveRegion(struct ARMCore* cpu, uint32_t address) {
 			value = 0; \
 			break; \
 		} \
-		address &= 0x00017FFC; \
+		LOAD_32(value, address & 0x00017FFC, gba->video.vram); \
+	} else { \
+		LOAD_32(value, address & 0x0001FFFC, gba->video.vram); \
 	} \
-	LOAD_32(value, address & 0x0001FFFC, gba->video.vram); \
 	wait += waitstatesRegion[REGION_VRAM];
 
 #define LOAD_OAM LOAD_32(value, address & (SIZE_OAM - 4), gba->video.oam.raw);
@@ -530,9 +531,10 @@ uint32_t GBALoad16(struct ARMCore* cpu, uint32_t address, int* cycleCounter) {
 				value = 0;
 				break;
 			}
-			address &= 0x00017FFE;
+			LOAD_16(value, address & 0x00017FFE, gba->video.vram);
+		} else {
+			LOAD_16(value, address & 0x0001FFFE, gba->video.vram);
 		}
-		LOAD_16(value, address & 0x0001FFFE, gba->video.vram);
 		break;
 	case REGION_OAM:
 		LOAD_16(value, address & (SIZE_OAM - 2), gba->video.oam.raw);
@@ -645,9 +647,10 @@ uint32_t GBALoad8(struct ARMCore* cpu, uint32_t address, int* cycleCounter) {
 				value = 0;
 				break;
 			}
-			address &= 0x00017FFF;
+			value = ((uint8_t*) gba->video.vram)[address & 0x00017FFF];
+		} else {
+			value = ((uint8_t*) gba->video.vram)[address & 0x0001FFFF];
 		}
-		value = ((uint8_t*) gba->video.vram)[address & 0x0001FFFF];
 		break;
 	case REGION_OAM:
 		value = ((uint8_t*) gba->video.oam.raw)[address & (SIZE_OAM - 1)];
@@ -734,13 +737,19 @@ uint32_t GBALoad8(struct ARMCore* cpu, uint32_t address, int* cycleCounter) {
 			mLOG(GBA_MEM, GAME_ERROR, "Bad VRAM Store32: 0x%08X", address); \
 			break; \
 		} \
-		address &= 0x00017FFC; \
-	} \
-	LOAD_32(oldValue, address & 0x0001FFFC, gba->video.vram); \
-	if (oldValue != value) { \
-		STORE_32(value, address & 0x0001FFFC, gba->video.vram); \
-		gba->video.renderer->writeVRAM(gba->video.renderer, (address & 0x0001FFFC) + 2); \
-		gba->video.renderer->writeVRAM(gba->video.renderer, (address & 0x0001FFFC)); \
+		LOAD_32(oldValue, address & 0x00017FFC, gba->video.vram); \
+		if (oldValue != value) { \
+			STORE_32(value, address & 0x00017FFC, gba->video.vram); \
+			gba->video.renderer->writeVRAM(gba->video.renderer, (address & 0x00017FFC) + 2); \
+			gba->video.renderer->writeVRAM(gba->video.renderer, (address & 0x00017FFC)); \
+		} \
+	} else { \
+		LOAD_32(oldValue, address & 0x0001FFFC, gba->video.vram); \
+		if (oldValue != value) { \
+			STORE_32(value, address & 0x0001FFFC, gba->video.vram); \
+			gba->video.renderer->writeVRAM(gba->video.renderer, (address & 0x0001FFFC) + 2); \
+			gba->video.renderer->writeVRAM(gba->video.renderer, (address & 0x0001FFFC)); \
+		} \
 	} \
 	wait += waitstatesRegion[REGION_VRAM];
 
@@ -855,12 +864,17 @@ void GBAStore16(struct ARMCore* cpu, uint32_t address, int16_t value, int* cycle
 				mLOG(GBA_MEM, GAME_ERROR, "Bad VRAM Store16: 0x%08X", address);
 				break;
 			}
-			address &= 0x00017FFE;
-		}
-		LOAD_16(oldValue, address & 0x0001FFFE, gba->video.vram);
-		if (value != oldValue) {
-			STORE_16(value, address & 0x0001FFFE, gba->video.vram);
-			gba->video.renderer->writeVRAM(gba->video.renderer, address & 0x0001FFFE);
+			LOAD_16(oldValue, address & 0x00017FFE, gba->video.vram);
+			if (value != oldValue) {
+				STORE_16(value, address & 0x00017FFE, gba->video.vram);
+				gba->video.renderer->writeVRAM(gba->video.renderer, address & 0x00017FFE);
+			}
+		} else {
+			LOAD_16(oldValue, address & 0x0001FFFE, gba->video.vram);
+			if (value != oldValue) {
+				STORE_16(value, address & 0x0001FFFE, gba->video.vram);
+				gba->video.renderer->writeVRAM(gba->video.renderer, address & 0x0001FFFE);
+			}
 		}
 		break;
 	case REGION_OAM: