From 89864b08162c32f90373d660c87078e9a197de70 Mon Sep 17 00:00:00 2001
From: goyuken <goyuken@4bbf4f03-6f44-549e-7e59-35d4b0962838>
Date: Mon, 29 Dec 2014 22:56:46 +0000
Subject: [PATCH] GB: add ability to load VBA saves with RTC, although the
 clock time itself is invariably trashed.  seems to work with pokeymans gold

---
 .../Consoles/Nintendo/Gameboy/Gambatte.cs     | 32 +++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
index d93c7170bd..c5c19832be 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs
@@ -498,10 +498,38 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 				return new byte[0];
 		}
 
+		private byte[] FixRTC(byte[] data, int offset)
+		{
+			// length - offset is the start of the VBA-only data; so
+			// length - offset - 4 is the start of the RTC block
+			int idx = data.Length - offset - 4;
+
+			byte[] ret = new byte[idx + 4];
+			Buffer.BlockCopy(data, 0, ret, 0, idx);
+			data[idx] = (byte)zerotime;
+			data[idx + 1] = (byte)(zerotime >> 8);
+			data[idx + 2] = (byte)(zerotime >> 16);
+			data[idx + 3] = (byte)(zerotime >> 24);
+
+			return ret;
+		}
+
 		public void StoreSaveRam(byte[] data)
 		{
-			if (data.Length != LibGambatte.gambatte_savesavedatalength(GambatteState))
-				throw new ArgumentException("Size of saveram data does not match expected!");
+			int expected = LibGambatte.gambatte_savesavedatalength(GambatteState);
+			switch (data.Length - expected)
+			{
+				case 0:
+					break;
+				default:
+					throw new ArgumentException("Size of saveram data does not match expected!");
+				case 44:
+					data = FixRTC(data, 44);
+					break;
+				case 40:
+					data = FixRTC(data, 40);
+					break;
+			}
 			LibGambatte.gambatte_loadsavedata(GambatteState, data);
 		}