M CHANGES → CHANGES

@@ -13,6 +13,7 @@ - DS GX: Fix incorrect W values
  - DS Video: Fix 2D/3D blending alpha values
  - DS I/O: Enable POWCNT1 bit 1 at boot (fixes mgba.io/i/616)
  - DS Slot-1: Reply to IR 0x08 command properly (fixes mgba.io/i/666)
+ - GBA Video: Fix mode 2 out-of-bounds VRAM crash
 Misc:
  - DS GX: Clean up and unify texture mapping
  - DS Core: Add symbol loading

M src/gba/renderers/software-bg.c → src/gba/renderers/software-bg.c

@@ -33,7 +33,12 @@
 #define MODE_2_NO_MOSAIC(COORD) \
 	COORD \
 	uint32_t screenBase = background->screenBase + (localX >> 11) + (((localY >> 7) & 0x7F0) << background->size); \
-	mapData = ((uint8_t*) renderer->d.vramBG[screenBase >> VRAM_BLOCK_OFFSET])[screenBase & VRAM_BLOCK_MASK]; \
+	uint8_t* screenBlock = (uint8_t*) renderer->d.vramBG[screenBase >> VRAM_BLOCK_OFFSET]; \
+	if (UNLIKELY(!screenBlock)) { \
+		mapData = 0; \
+	} else { \
+		mapData = screenBlock[screenBase & VRAM_BLOCK_MASK]; \
+	} \
 	uint32_t charBase = background->charBase + (mapData << 6) + ((localY & 0x700) >> 5) + ((localX & 0x700) >> 8); \
 	pixelData = ((uint8_t*) renderer->d.vramBG[charBase >> VRAM_BLOCK_OFFSET])[charBase & VRAM_BLOCK_MASK]; \