From 8435c09b6547fe3e22362b5cfda7b7e05c767b01 Mon Sep 17 00:00:00 2001
From: Daryl <Daryl@DARYL-LAPTOP.mshome.net>
Date: Sun, 28 Jun 2020 21:24:42 -0600
Subject: [PATCH] BSX rom is now optional. if missing, it will load directly
 into the game.

---
 readme.txt             |  4 ++--
 source/filebrowser.cpp |  9 +++------
 source/snes9x/bsx.cpp  | 42 +++++++++++++++++++++++++++++++++++-------
 3 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/readme.txt b/readme.txt
index 6a723ce..b495a53 100644
--- a/readme.txt
+++ b/readme.txt
@@ -600,8 +600,8 @@ done you can proceed to run the emulator via the Homebrew Channel.
 
 -=[ Satellaview (BS-X) ]=-
 
-Snes9x GX supports loading BS games. The BSX BIOS is required.
-Download the English + No DRM BS-X ROM here: 
+Snes9x GX supports loading BS games. The BSX BIOS is not required.
+If you wish to use one, download the English + No DRM BS-X ROM here: 
 https://project.satellaview.org/downloads.htm 
 
 Put it in your snes9xgx folder, renamed to BS-X.bin.
diff --git a/source/filebrowser.cpp b/source/filebrowser.cpp
index 8dc2400..28f36eb 100644
--- a/source/filebrowser.cpp
+++ b/source/filebrowser.cpp
@@ -49,6 +49,7 @@ bool inSz = false;
 
 unsigned long SNESROMSize = 0;
 bool loadingFile = false;
+bool bsxBiosLoadFailed;
 
 extern bool isBSX();
 
@@ -377,9 +378,10 @@ static bool IsValidROM()
 
 			if(p != NULL)
 			{
-				if (strcasecmp(p, ".smc") == 0 ||
+				if (strcasecmp(p, ".bs") == 0 ||
 					strcasecmp(p, ".fig") == 0 ||
 					strcasecmp(p, ".sfc") == 0 ||
+					strcasecmp(p, ".smc") == 0 ||
 					strcasecmp(p, ".swc") == 0)
 				{
 					if(zippedFilename) free(zippedFilename);
@@ -455,8 +457,6 @@ int BrowserLoadSz()
 	return szfiles;
 }
 
-static bool bsxBiosLoadFailed;
-
 int WiiFileLoader()
 {
 	size_t size;
@@ -531,9 +531,6 @@ int BrowserLoadFile()
 	{
 		ErrorPrompt("Error loading game!");
 	}
-	else if(bsxBiosLoadFailed) {
-		ErrorPrompt("BS-X BIOS file not found!");
-	}
 	else
 	{
 		// load SRAM or snapshot
diff --git a/source/snes9x/bsx.cpp b/source/snes9x/bsx.cpp
index 6bffebc..4f4f504 100644
--- a/source/snes9x/bsx.cpp
+++ b/source/snes9x/bsx.cpp
@@ -14,6 +14,8 @@
 #include "display.h"
 #include <math.h>
 
+extern bool bsxBiosLoadFailed;
+
 //#define BSX_DEBUG
 
 #define BIOS_SIZE	0x100000
@@ -1209,7 +1211,7 @@ uint8 * S9xGetBasePointerBSX (uint32 address)
 static bool8 BSX_LoadBIOS (void)
 {
 #ifdef GEKKO
-	return FALSE; // We're not loading the BIOS!
+	return TRUE; // We're not loading the BIOS!
 #else
 	FILE	*fp;
 	char	path[PATH_MAX + 1], name[PATH_MAX + 1];
@@ -1305,7 +1307,7 @@ void S9xInitBSX (void)
 			uint8	*header = r1 ? Memory.ROM + 0x7FC0 : Memory.ROM + 0xFFC0;
 
 			FlashMode = (header[0x18] & 0xEF) == 0x20 ? FALSE : TRUE;
-			FlashSize = FLASH_SIZE;
+			FlashSize = (header[0x19] & 0x20) ? PSRAM_SIZE : FLASH_SIZE;
 
 			// Fix Block Allocation Flags
 			// (for games that don't have it setup properly,
@@ -1374,12 +1376,38 @@ void S9xResetBSX (void)
 	BSX.out_index = 0;
 	memset(BSX.output, 0, sizeof(BSX.output));
 
-	// starting from the bios
-	BSX.MMC[0x02] = BSX.MMC[0x03] = BSX.MMC[0x05] = BSX.MMC[0x06] = 0x80;
-	BSX.MMC[0x09] = BSX.MMC[0x0B] = 0x80;
+	if(bsxBiosLoadFailed) {
+		BSX.MMC[0x02] = FlashMode ? 0x80: 0;
 
-	BSX.MMC[0x07] = BSX.MMC[0x08] = 0x80;
-	BSX.MMC[0x0E] = 0x80;
+		// per bios: run from psram or flash card
+		if (FlashSize == PSRAM_SIZE)
+		{
+			memcpy(PSRAM, FlashROM, PSRAM_SIZE);
+
+			BSX.MMC[0x01] = 0x80;
+			BSX.MMC[0x03] = 0x80;
+			BSX.MMC[0x04] = 0x80;
+			BSX.MMC[0x0C] = 0x80;
+			BSX.MMC[0x0D] = 0x80;
+		}
+		else
+		{
+			BSX.MMC[0x03] = 0x80;
+			BSX.MMC[0x05] = 0x80;
+			BSX.MMC[0x06] = 0x80;
+			BSX.MMC[0x09] = BSX.MMC[0x0B] = 0x80;
+		}
+
+		BSX.MMC[0x0E] = 0x80;
+	}
+	else {
+		// starting from the bios
+		BSX.MMC[0x02] = BSX.MMC[0x03] = BSX.MMC[0x05] = BSX.MMC[0x06] = 0x80;
+		BSX.MMC[0x09] = BSX.MMC[0x0B] = 0x80;
+
+		BSX.MMC[0x07] = BSX.MMC[0x08] = 0x80;
+		BSX.MMC[0x0E] = 0x80;
+	}
 
 	// default register values
 	BSX.PPU[0x2196 - BSXPPUBASE] = 0x10;