From 3ceadd4ccdb70574bc09d1a1270ab5d9341de776 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Thu, 22 Sep 2016 06:49:32 -0700
Subject: [PATCH] GB Memory: Initialize RAM pattern for GBC

---
 CHANGES         |  1 +
 src/gb/memory.c | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/CHANGES b/CHANGES
index b132c7a46..5ac343140 100644
--- a/CHANGES
+++ b/CHANGES
@@ -14,6 +14,7 @@ Bugfixes:
 Misc:
  - All: Only update version info if needed
  - FFmpeg: Encoding cleanup
+ - GB Memory: Initialize RAM pattern for GBC
 
 0.5.0: (2016-09-19)
 Features:
diff --git a/src/gb/memory.c b/src/gb/memory.c
index 19564b09d..43f39ec21 100644
--- a/src/gb/memory.c
+++ b/src/gb/memory.c
@@ -89,6 +89,20 @@ void GBMemoryReset(struct GB* gb) {
 		mappedMemoryFree(gb->memory.wram, GB_SIZE_WORKING_RAM);
 	}
 	gb->memory.wram = anonymousMemoryMap(GB_SIZE_WORKING_RAM);
+	if (gb->model >= GB_MODEL_CGB) {
+		uint32_t* base = (uint32_t*) gb->memory.wram;
+		size_t i;
+		uint32_t pattern = 0;
+		for (i = 0; i < GB_SIZE_WORKING_RAM / 4; i += 4) {
+			if ((i & 0x1FF) == 0) {
+				pattern = ~pattern;
+			}
+			base[i + 0] = pattern;
+			base[i + 1] = pattern;
+			base[i + 2] = ~pattern;
+			base[i + 3] = ~pattern;
+		}
+	}
 	GBMemorySwitchWramBank(&gb->memory, 1);
 	gb->memory.romBank = &gb->memory.rom[GB_SIZE_CART_BANK0];
 	gb->memory.currentBank = 1;