From a07e4c6c49c76d3c4b2500077a708410a8b73978 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 15:06:25 +0200
Subject: [PATCH 01/19] Add mem descriptors to libretro.h.

---
 libretro/libretro.h | 101 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/libretro/libretro.h b/libretro/libretro.h
index a51cfc06..ac7319e7 100755
--- a/libretro/libretro.h
+++ b/libretro/libretro.h
@@ -180,6 +180,9 @@ extern "C" {
 // Video ram lets a frontend peek into a game systems video RAM (VRAM).
 #define RETRO_MEMORY_VIDEO_RAM   3
 
+// ROM lets a frontend poke a game system's main program.
+#define RETRO_MEMORY_ROM         4
+
 // Keysyms used for ID in input state callback when polling RETRO_KEYBOARD.
 enum retro_key
 {
@@ -637,6 +640,104 @@ enum retro_mod
                                            // The core must pass an array of const struct retro_controller_info which is terminated with
                                            // a blanked out struct. Each element of the struct corresponds to an ascending port index to retro_set_controller_port_device().
                                            // Even if special device types are set in the libretro core, libretro should only poll input based on the base input device types.
+#define RETRO_ENVIRONMENT_SET_MEMORY_MAPS (36 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           // const struct retro_memory_map * --
+                                           // This environment call lets a libretro core tell the frontend about the memory maps
+                                           // emulated by this core. This can be used to implement, for example, cheats.
+                                           //
+                                           // Should only be used by emulators; it doesn't make much sense for anything else.
+                                           //
+                                           // It is highly recommended to expose all relevant pointers through retro_get_memory_* as well.
+                                           //
+                                           // Can be called from retro_init and retro_load_game.
+                                           //
+
+#define RETRO_MEMDESC_CONST     (1 << 0) // The frontend will never change this memory area once retro_load_game has returned.
+#define RETRO_MEMDESC_BIGENDIAN (1 << 1) // The memory area contains big endian data. Default is little endian.
+#define RETRO_MEMDESC_ALIGNED   (1 << 2) // All memory access in this area is aligned to their own size, and no non-power-of-two sized data exists.
+struct retro_memory_descriptor {
+   uint64_t flags;
+   
+   //Pointer to the start of the relevant ROM or RAM chip. Do not do math on this; the frontend may group things with identical pointers together.
+   //If 'start' does not point to the first byte in the pointer, put the difference in 'offset' instead.
+   //May be NULL if there's nothing usable here (e.g. hardware registers and open bus). No flags should be set if the pointer is NULL.
+   void * ptr;
+   size_t offset;
+   
+   //This is the location in the emulated address space where the mapping starts.
+   size_t start;
+   
+   //Which bits must be same as in 'start' for this mapping to apply.
+   //The first memory descriptor to claim a certain byte is the one that applies.
+   //A bit which is set in 'start' must also be set in this.
+   //Can be zero, in which case each byte is assumed mapped exactly once. In this case, 'len' must be a power of two.
+   size_t select;
+   
+   //If this is nonzero, the set bits are assumed not connected to the memory chip's address pins.
+   size_t disconnect;
+   
+   //This one tells the size of the current memory area.
+   //If, after start+disconnect are applied, the address is higher than this, the highest bit of the address is cleared.
+   //If the address is still too high, the next highest bit is cleared.
+   //Can be zero, in which case it's assumed to be infinite (as limited by 'select' and 'disconnect').
+   size_t len;
+   
+   //To go from emulated address to physical address, the following order applies:
+   //Subtract 'start', pick off 'disconnect', apply 'len', add 'offset'.
+   
+   //The address space name must consist of only a-zA-Z0-9_-, should be as short as feasible (maximum length is 8 plus the NUL),
+   // and may not be any other address space plus one or more 0-9A-F at the end.
+   //However, multiple memory descriptors for the same address space is allowed, and the address
+   // space name can be empty. NULL is treated as empty.
+   //Address space names are case sensitive, but avoid lowercase if possible.
+   //The same pointer may exist in multiple address spaces.
+   //Examples:
+   // blank+blank - valid (multiple things may be mapped in the same namespace)
+   // 'Sp'+'Sp' - valid (multiple things may be mapped in the same namespace)
+   // 'A'+'B' - valid (neither is a prefix of each other)
+   // 'S'+blank - valid ('S' is not in 0-9A-F)
+   // 'a'+blank - valid ('a' is not in 0-9A-F)
+   // 'a'+'A' - valid (neither is a prefix of each other)
+   // 'AR'+blank - valid ('R' is not in 0-9A-F)
+   // 'ARB'+blank - valid (the B can't be part of the address either, because there is no namespace 'AR')
+   // blank+'B' - not valid, because it's ambigous which address space B1234 would refer to.
+   //  The length can't be used for that purpose; the frontend may want to append arbitrary data to an address, without a separator.
+   const char * addrspace;
+};
+//The frontend may use the largest value of 'start'+'select' in a certain namespace to infer the size of the address space.
+//If the address space is larger than that, a mapping with .ptr=NULL should be at the end of the array, with .select set to all ones for as long as the address space is big.
+//Sample descriptors (minus .ptr, and RETRO_MEMFLAG_ on the flags):
+//SNES WRAM:
+// .start=0x7E0000, .len=0x20000
+//(Note that this must be mapped before the ROM in most cases; some of the ROM mappers try to claim $7E0000, or at least $7E8000.)
+//SNES SPC700 RAM:
+// .addrspace="S", .len=0x10000
+//SNES WRAM mirrors:
+// .flags=MIRROR, .start=0x000000, .select=0xC0E000, .len=0x2000
+// .flags=MIRROR, .start=0x800000, .select=0xC0E000, .len=0x2000
+//SNES WRAM mirrors, alternate equivalent descriptor:
+// .flags=MIRROR, .select=0x40E000, .disconnect=~0x1FFF
+//(Various similar constructions can be created by combining parts of the above two.)
+//SNES LoROM (512KB, mirrored a couple of times):
+// .flags=CONST, .start=0x008000, .select=0x408000, .disconnect=0x8000, .len=512*1024
+// .flags=CONST, .start=0x400000, .select=0x400000, .disconnect=0x8000, .len=512*1024
+//SNES HiROM (4MB):
+// .flags=CONST,                 .start=0x400000, .select=0x400000, .len=4*1024*1024
+// .flags=CONST, .offset=0x8000, .start=0x008000, .select=0x408000, .len=4*1024*1024
+//SNES ExHiROM (8MB):
+// .flags=CONST, .offset=0,                  .start=0xC00000, .select=0xC00000, .len=4*1024*1024
+// .flags=CONST, .offset=4*1024*1024,        .start=0x400000, .select=0xC00000, .len=4*1024*1024
+// .flags=CONST, .offset=0x8000,             .start=0x808000, .select=0xC08000, .len=4*1024*1024
+// .flags=CONST, .offset=4*1024*1024+0x8000, .start=0x008000, .select=0xC08000, .len=4*1024*1024
+//Clarify the size of the address space:
+// .ptr=NULL, .select=0xFFFFFF
+//.len can be implied by .select in many of them, but was included for clarity.
+
+struct retro_memory_map
+{
+   const struct retro_memory_descriptor * descriptors;
+   unsigned num_descriptors;
+};
 
 struct retro_controller_description
 {

From 2313dc0ce49fb807765a9cef7e0a48e4ef4093ef Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 16:30:56 +0200
Subject: [PATCH 02/19] Start adding this. Those mapping functions will take
 quite a while to figure out...

---
 libretro/libretro.cpp |  31 +++++++++++
 libretro/libretro.h   |   4 +-
 memmap.cpp            | 117 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 151 insertions(+), 1 deletion(-)

diff --git a/libretro/libretro.cpp b/libretro/libretro.cpp
index 8d9c6ec7..b2383fd7 100644
--- a/libretro/libretro.cpp
+++ b/libretro/libretro.cpp
@@ -320,8 +320,31 @@ void retro_cheat_set(unsigned index, bool enabled, const char *code)
    S9xApplyCheats();
 }
 
+static struct retro_memory_descriptor memorydesc[64];
+static unsigned memorydesc_c;
+void S9xAppendMapping(struct retro_memory_descriptor * desc)
+{
+	//do it backwards - snes9x defines the last one to win, while we define the first one to win
+	memcpy(&memorydesc[64 - (++memorydesc_c)], desc, sizeof(struct retro_memory_descriptor));
+}
+
+//#define RETRO_MEMDESC_CONST (1 << 0)
+//struct retro_memory_descriptor {
+//   uint64_t flags;
+//   void * ptr;
+//   size_t offset;
+//   size_t start;
+//   size_t select;
+//   size_t disconnect;
+//   size_t len;
+//   const char * addrspace;
+//};
+//void S9xAppendMapping(struct retro_memory_descriptor desc);
+
 bool retro_load_game(const struct retro_game_info *game)
 {
+   memorydesc_c = 0;
+   
    if(game->data == NULL && game->size == 0 && game->path != NULL)
       rom_loaded = Memory.LoadROM(game->path);
    else
@@ -330,6 +353,9 @@ bool retro_load_game(const struct retro_game_info *game)
    if (!rom_loaded && log_cb)
       log_cb(RETRO_LOG_ERROR, "[libretro]: Rom loading failed...\n");
    
+   struct retro_memory_map map={ memorydesc+64-memorydesc_c, memorydesc_c };
+   if (rom_loaded) environ_cb(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &map);
+   
    return rom_loaded;
 }
 
@@ -339,6 +365,8 @@ void retro_unload_game(void)
 bool retro_load_game_special(unsigned game_type,
       const struct retro_game_info *info, size_t num_info) {
 
+  memorydesc_c = 0;
+  
   switch (game_type) {
      case RETRO_GAME_TYPE_BSX:
        
@@ -380,6 +408,9 @@ bool retro_load_game_special(unsigned game_type,
        rom_loaded = false;
        break;
   }
+  
+  struct retro_memory_map map={ memorydesc+64-memorydesc_c, memorydesc_c };
+  if (rom_loaded) environ_cb(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &map);
 
   return rom_loaded;
 }
diff --git a/libretro/libretro.h b/libretro/libretro.h
index ac7319e7..c62dcc94 100755
--- a/libretro/libretro.h
+++ b/libretro/libretro.h
@@ -658,7 +658,9 @@ enum retro_mod
 struct retro_memory_descriptor {
    uint64_t flags;
    
-   //Pointer to the start of the relevant ROM or RAM chip. Do not do math on this; the frontend may group things with identical pointers together.
+   //Pointer to the start of the relevant ROM or RAM chip.
+   //It's strongly recommended to use 'offset' if possible, rather than doing math on the pointer.
+   //If the same byte is mapped my multiple descriptors, their descriptors must have the same pointer.
    //If 'start' does not point to the first byte in the pointer, put the difference in 'offset' instead.
    //May be NULL if there's nothing usable here (e.g. hardware registers and open bus). No flags should be set if the pointer is NULL.
    void * ptr;
diff --git a/memmap.cpp b/memmap.cpp
index fa1230f1..cdb2d4b8 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -201,6 +201,11 @@
 #include "movie.h"
 #include "display.h"
 
+#ifdef __LIBRETRO__
+#include "libretro.h"
+void S9xAppendMapping(struct retro_memory_descriptor * desc);
+#endif
+
 #ifndef SET_UI_COLOR
 #define SET_UI_COLOR(r, g, b) ;
 #endif
@@ -2773,6 +2778,17 @@ void CMemory::map_lorom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 			BlockIsRAM[p] = FALSE;
 		}
 	}
+
+#ifdef __LIBRETRO__
+	struct retro_memory_descriptor desc = {0};
+	desc.flags=RETRO_MEMDESC_CONST;
+	desc.ptr=ROM;
+	desc.offset=0;//
+	desc.start=0;//
+	desc.select=0x8000;
+	desc.len=0;//
+	S9xAppendMapping(&desc);
+#endif
 }
 
 void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size)
@@ -2790,6 +2806,18 @@ void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 			BlockIsRAM[p] = FALSE;
 		}
 	}
+
+#ifdef __LIBRETRO__
+	struct retro_memory_descriptor desc = {0};
+	desc.flags=RETRO_MEMDESC_CONST;
+	desc.ptr=ROM;
+	desc.offset=0;//
+	desc.start=0;//
+	desc.select=0;//
+	desc.disconnect=0;
+	desc.len=0;//
+	S9xAppendMapping(&desc);
+#endif
 }
 
 void CMemory::map_lorom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, uint32 offset)
@@ -2807,6 +2835,18 @@ void CMemory::map_lorom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 			BlockIsRAM[p] = FALSE;
 		}
 	}
+
+#ifdef __LIBRETRO__
+	struct retro_memory_descriptor desc = {0};
+	desc.flags=RETRO_MEMDESC_CONST;
+	desc.ptr=ROM;
+	desc.offset=0;//
+	desc.start=0;//
+	desc.select=0;//
+	desc.disconnect=0x8000;
+	desc.len=0;//
+	S9xAppendMapping(&desc);
+#endif
 }
 
 void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, uint32 offset)
@@ -2824,6 +2864,17 @@ void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 			BlockIsRAM[p] = FALSE;
 		}
 	}
+#ifdef __LIBRETRO__
+	struct retro_memory_descriptor desc = {0};
+	desc.flags=RETRO_MEMDESC_CONST;
+	desc.ptr=ROM;
+	desc.offset=0;//
+	desc.start=0;//
+	desc.select=0;//
+	desc.disconnect=0x0000;
+	desc.len=0;//
+	S9xAppendMapping(&desc);
+#endif
 }
 
 void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint8 *data)
@@ -2840,6 +2891,18 @@ void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 			BlockIsRAM[p] = TRUE;
 		}
 	}
+#ifdef __LIBRETRO__
+	struct retro_memory_descriptor desc = {0};
+	desc.flags=0;
+	desc.ptr=data;
+	desc.offset=0;
+	if (data == RAM+0x10000) { desc.ptr=RAM; desc.offset=0x10000; }
+	desc.start=0;//
+	desc.select=0;//
+	desc.disconnect=0;//
+	desc.len=0;//
+	S9xAppendMapping(&desc);
+#endif
 }
 
 void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, int index, int type)
@@ -2860,6 +2923,60 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 			BlockIsRAM[p] = isRAM;
 		}
 	}
+#ifdef __LIBRETRO__
+	struct retro_memory_descriptor desc = {0};
+	desc.flags=RETRO_MEMDESC_CONST;
+	desc.ptr=NULL;//this function maps funky stuff like hardware regs, but also various SRAM
+//the following should be handled:
+/*
+		case CMemory::MAP_LOROM_SRAM:
+			if (Memory.SRAMMask)
+			{
+				*(Memory.SRAM + ((((Address & 0xff0000) >> 1) | (Address & 0x7fff)) & Memory.SRAMMask)) = Byte;
+				CPU.SRAMModified = TRUE;
+			}
+
+			addCyclesInMemoryAccess;
+			return;
+
+		case CMemory::MAP_LOROM_SRAM_B:
+			if (Multi.sramMaskB)
+			{
+				*(Multi.sramB + ((((Address & 0xff0000) >> 1) | (Address & 0x7fff)) & Multi.sramMaskB)) = Byte;
+				CPU.SRAMModified = TRUE;
+			}
+
+			addCyclesInMemoryAccess;
+			return;
+
+		case CMemory::MAP_HIROM_SRAM:
+			if (Memory.SRAMMask)
+			{
+				*(Memory.SRAM + (((Address & 0x7fff) - 0x6000 + ((Address & 0xf0000) >> 3)) & Memory.SRAMMask)) = Byte;
+				CPU.SRAMModified = TRUE;
+			}
+
+			addCyclesInMemoryAccess;
+			return;
+
+		case CMemory::MAP_BWRAM:
+			*(Memory.BWRAM + ((Address & 0x7fff) - 0x6000)) = Byte;
+			CPU.SRAMModified = TRUE;
+			addCyclesInMemoryAccess;
+			return;
+
+		case CMemory::MAP_SA1RAM:
+			*(Memory.SRAM + (Address & 0xffff)) = Byte;
+			addCyclesInMemoryAccess;
+			return;
+*/
+	desc.offset=0;//
+	desc.start=0;//
+	desc.select=0;//
+	desc.disconnect=0;//
+	desc.len=0;//
+	S9xAppendMapping(&desc);
+#endif
 }
 
 void CMemory::map_System (void)

From bb7850dd39b068b20392233922878c16fbc1b3b5 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 17:08:05 +0200
Subject: [PATCH 03/19] WRAM works now. Gonna implement the rest of the
 descriptors now...

---
 libretro/libretro.cpp | 13 -------------
 libretro/libretro.h   |  1 +
 memmap.cpp            | 22 +++++++++++-----------
 3 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/libretro/libretro.cpp b/libretro/libretro.cpp
index b2383fd7..2e91fc38 100644
--- a/libretro/libretro.cpp
+++ b/libretro/libretro.cpp
@@ -328,19 +328,6 @@ void S9xAppendMapping(struct retro_memory_descriptor * desc)
 	memcpy(&memorydesc[64 - (++memorydesc_c)], desc, sizeof(struct retro_memory_descriptor));
 }
 
-//#define RETRO_MEMDESC_CONST (1 << 0)
-//struct retro_memory_descriptor {
-//   uint64_t flags;
-//   void * ptr;
-//   size_t offset;
-//   size_t start;
-//   size_t select;
-//   size_t disconnect;
-//   size_t len;
-//   const char * addrspace;
-//};
-//void S9xAppendMapping(struct retro_memory_descriptor desc);
-
 bool retro_load_game(const struct retro_game_info *game)
 {
    memorydesc_c = 0;
diff --git a/libretro/libretro.h b/libretro/libretro.h
index c62dcc94..e63aebb2 100755
--- a/libretro/libretro.h
+++ b/libretro/libretro.h
@@ -663,6 +663,7 @@ struct retro_memory_descriptor {
    //If the same byte is mapped my multiple descriptors, their descriptors must have the same pointer.
    //If 'start' does not point to the first byte in the pointer, put the difference in 'offset' instead.
    //May be NULL if there's nothing usable here (e.g. hardware registers and open bus). No flags should be set if the pointer is NULL.
+   //It's recommended to minimize the number of descriptors if possible, but not mandatory.
    void * ptr;
    size_t offset;
    
diff --git a/memmap.cpp b/memmap.cpp
index cdb2d4b8..3b0b8797 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2787,7 +2787,7 @@ void CMemory::map_lorom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	desc.start=0;//
 	desc.select=0x8000;
 	desc.len=0;//
-	S9xAppendMapping(&desc);
+	//S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2816,7 +2816,7 @@ void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	desc.select=0;//
 	desc.disconnect=0;
 	desc.len=0;//
-	S9xAppendMapping(&desc);
+	//S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2845,7 +2845,7 @@ void CMemory::map_lorom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 	desc.select=0;//
 	desc.disconnect=0x8000;
 	desc.len=0;//
-	S9xAppendMapping(&desc);
+	//S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2873,7 +2873,7 @@ void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 	desc.select=0;//
 	desc.disconnect=0x0000;
 	desc.len=0;//
-	S9xAppendMapping(&desc);
+	//S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2896,11 +2896,11 @@ void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	desc.flags=0;
 	desc.ptr=data;
 	desc.offset=0;
-	if (data == RAM+0x10000) { desc.ptr=RAM; desc.offset=0x10000; }
-	desc.start=0;//
-	desc.select=0;//
-	desc.disconnect=0;//
-	desc.len=0;//
+	desc.start=bank_s<<16 | addr_s;
+	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+	desc.disconnect=0;
+	desc.len=0;
+if (bank_s==0x7e || bank_s==0x7f)
 	S9xAppendMapping(&desc);
 #endif
 }
@@ -2975,7 +2975,7 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	desc.select=0;//
 	desc.disconnect=0;//
 	desc.len=0;//
-	S9xAppendMapping(&desc);
+	//S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2993,8 +2993,8 @@ void CMemory::map_System (void)
 void CMemory::map_WRAM (void)
 {
 	// will overwrite others
-	map_space(0x7e, 0x7e, 0x0000, 0xffff, RAM);
 	map_space(0x7f, 0x7f, 0x0000, 0xffff, RAM + 0x10000);
+	map_space(0x7e, 0x7e, 0x0000, 0xffff, RAM);
 }
 
 void CMemory::map_LoROMSRAM (void)

From 2401f86259c647d23a79e6b96b82797a9d4a4deb Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 18:10:49 +0200
Subject: [PATCH 04/19] Almost done, only need to map up those kinds of SRAM.

---
 memmap.cpp | 46 +++++++++++++++++++---------------------------
 1 file changed, 19 insertions(+), 27 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index 3b0b8797..aa27f54f 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2783,11 +2783,11 @@ void CMemory::map_lorom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	struct retro_memory_descriptor desc = {0};
 	desc.flags=RETRO_MEMDESC_CONST;
 	desc.ptr=ROM;
-	desc.offset=0;//
-	desc.start=0;//
-	desc.select=0x8000;
-	desc.len=0;//
-	//S9xAppendMapping(&desc);
+	desc.start=bank_s<<16 | addr_s;
+	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+	desc.disconnect=0x8000;
+	desc.len=size;
+	S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2811,12 +2811,10 @@ void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	struct retro_memory_descriptor desc = {0};
 	desc.flags=RETRO_MEMDESC_CONST;
 	desc.ptr=ROM;
-	desc.offset=0;//
-	desc.start=0;//
-	desc.select=0;//
-	desc.disconnect=0;
-	desc.len=0;//
-	//S9xAppendMapping(&desc);
+	desc.start=bank_s<<16 | addr_s;
+	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+	desc.len=size;
+	S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2840,12 +2838,12 @@ void CMemory::map_lorom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 	struct retro_memory_descriptor desc = {0};
 	desc.flags=RETRO_MEMDESC_CONST;
 	desc.ptr=ROM;
-	desc.offset=0;//
-	desc.start=0;//
-	desc.select=0;//
+	desc.offset=offset;
+	desc.start=bank_s<<16 | addr_s;
+	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
 	desc.disconnect=0x8000;
-	desc.len=0;//
-	//S9xAppendMapping(&desc);
+	desc.len=size;
+	S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2868,12 +2866,11 @@ void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 	struct retro_memory_descriptor desc = {0};
 	desc.flags=RETRO_MEMDESC_CONST;
 	desc.ptr=ROM;
-	desc.offset=0;//
-	desc.start=0;//
-	desc.select=0;//
-	desc.disconnect=0x0000;
-	desc.len=0;//
-	//S9xAppendMapping(&desc);
+	desc.offset=offset;
+	desc.start=bank_s<<16 | addr_s;
+	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+	desc.len=size;
+	S9xAppendMapping(&desc);
 #endif
 }
 
@@ -2893,14 +2890,9 @@ void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	}
 #ifdef __LIBRETRO__
 	struct retro_memory_descriptor desc = {0};
-	desc.flags=0;
 	desc.ptr=data;
-	desc.offset=0;
 	desc.start=bank_s<<16 | addr_s;
 	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-	desc.disconnect=0;
-	desc.len=0;
-if (bank_s==0x7e || bank_s==0x7f)
 	S9xAppendMapping(&desc);
 #endif
 }

From 0a4ff3707436864263f10b88ab5b818c69d7bf58 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 18:37:16 +0200
Subject: [PATCH 05/19] That's the SRAM too. And SA-1 RAM.

---
 memmap.cpp | 80 ++++++++++++++++++++----------------------------------
 1 file changed, 29 insertions(+), 51 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index aa27f54f..a0fe24e0 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2917,57 +2917,35 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	}
 #ifdef __LIBRETRO__
 	struct retro_memory_descriptor desc = {0};
-	desc.flags=RETRO_MEMDESC_CONST;
-	desc.ptr=NULL;//this function maps funky stuff like hardware regs, but also various SRAM
-//the following should be handled:
-/*
-		case CMemory::MAP_LOROM_SRAM:
-			if (Memory.SRAMMask)
-			{
-				*(Memory.SRAM + ((((Address & 0xff0000) >> 1) | (Address & 0x7fff)) & Memory.SRAMMask)) = Byte;
-				CPU.SRAMModified = TRUE;
-			}
-
-			addCyclesInMemoryAccess;
-			return;
-
-		case CMemory::MAP_LOROM_SRAM_B:
-			if (Multi.sramMaskB)
-			{
-				*(Multi.sramB + ((((Address & 0xff0000) >> 1) | (Address & 0x7fff)) & Multi.sramMaskB)) = Byte;
-				CPU.SRAMModified = TRUE;
-			}
-
-			addCyclesInMemoryAccess;
-			return;
-
-		case CMemory::MAP_HIROM_SRAM:
-			if (Memory.SRAMMask)
-			{
-				*(Memory.SRAM + (((Address & 0x7fff) - 0x6000 + ((Address & 0xf0000) >> 3)) & Memory.SRAMMask)) = Byte;
-				CPU.SRAMModified = TRUE;
-			}
-
-			addCyclesInMemoryAccess;
-			return;
-
-		case CMemory::MAP_BWRAM:
-			*(Memory.BWRAM + ((Address & 0x7fff) - 0x6000)) = Byte;
-			CPU.SRAMModified = TRUE;
-			addCyclesInMemoryAccess;
-			return;
-
-		case CMemory::MAP_SA1RAM:
-			*(Memory.SRAM + (Address & 0xffff)) = Byte;
-			addCyclesInMemoryAccess;
-			return;
-*/
-	desc.offset=0;//
-	desc.start=0;//
-	desc.select=0;//
-	desc.disconnect=0;//
-	desc.len=0;//
-	//S9xAppendMapping(&desc);
+	desc.start=bank_s<<16 | addr_s;
+	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+	if (type==MAP_LOROM_SRAM || type==MAP_SA1RAM)
+	{
+		desc.ptr=Memory.SRAM;
+		desc.disconnect=0x8000;
+		desc.len=Memory.SRAMMask+1;
+		S9xAppendMapping(&desc);
+	}
+	if (type==MAP_LOROM_SRAM_B)
+	{
+		desc.ptr=Multi.sramB;
+		desc.disconnect=0x8000;
+		desc.len=Multi.sramMaskB+1;
+		S9xAppendMapping(&desc);
+	}
+	if (type==MAP_HIROM_SRAM || type==MAP_RONLY_SRAM)
+	{
+		desc.ptr=Memory.SRAM;
+		desc.disconnect=0xF8E000;
+		desc.len=Memory.SRAMMask+1;
+		S9xAppendMapping(&desc);
+	}
+	if (type==MAP_BWRAM)
+	{
+		desc.ptr=Memory.BWRAM;
+		desc.disconnect=0xFFE000;
+		S9xAppendMapping(&desc);
+	}
 #endif
 }
 

From 39fa17f9db8a76215d35f85844c5a3b4228fca42 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 19:11:28 +0200
Subject: [PATCH 06/19] Export the ROM pointer.

---
 libretro/libretro.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libretro/libretro.cpp b/libretro/libretro.cpp
index 2e91fc38..7d4bfa56 100644
--- a/libretro/libretro.cpp
+++ b/libretro/libretro.cpp
@@ -706,6 +706,9 @@ void* retro_get_memory_data(unsigned type)
      case RETRO_MEMORY_VIDEO_RAM:
         data = Memory.VRAM;
         break;
+     case RETRO_MEMORY_ROM:
+        data = Memory.ROM;
+        break;
 	  default:
 	     data = NULL;
 		 break;
@@ -737,6 +740,9 @@ size_t retro_get_memory_size(unsigned type)
       case RETRO_MEMORY_VIDEO_RAM:
          size = 64 * 1024;
          break;
+      case RETRO_MEMORY_ROM:
+         size = Memory.CalculatedSize;
+         break;
 	  default:
 	     size = 0;
 		 break;

From 4fc2d661a45383091e9a30b60c778e787a09ac51 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 19:24:20 +0200
Subject: [PATCH 07/19] We need the SRAM mask inside the map ROM function, or
 we tell the front that SRAM is one byte. I'll move it over.

---
 memmap.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index a0fe24e0..c19f7306 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2532,6 +2532,9 @@ void CMemory::InitROM (void)
 	Map_Initialize();
 	CalculatedChecksum = 0;
 
+	// SRAM size
+	SRAMMask = SRAMSize ? ((1 << (SRAMSize + 3)) * 128) - 1 : 0;
+
 	if (HiROM)
     {
 		if (Settings.BS)
@@ -2662,9 +2665,6 @@ void CMemory::InitROM (void)
 		*p = 0;
 	}
 
-	// SRAM size
-	SRAMMask = SRAMSize ? ((1 << (SRAMSize + 3)) * 128) - 1 : 0;
-
 	// checksum
 	if (!isChecksumOK || ((uint32) CalculatedSize > (uint32) (((1 << (ROMSize - 7)) * 128) * 1024)))
 	{
@@ -2921,6 +2921,7 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
 	if (type==MAP_LOROM_SRAM || type==MAP_SA1RAM)
 	{
+puts("BBB");
 		desc.ptr=Memory.SRAM;
 		desc.disconnect=0x8000;
 		desc.len=Memory.SRAMMask+1;

From 62fd28d744986973b9d8671f0057936c8b650d58 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 19:25:00 +0200
Subject: [PATCH 08/19] Kill debug code.

---
 memmap.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/memmap.cpp b/memmap.cpp
index c19f7306..bc32c933 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2921,7 +2921,6 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
 	if (type==MAP_LOROM_SRAM || type==MAP_SA1RAM)
 	{
-puts("BBB");
 		desc.ptr=Memory.SRAM;
 		desc.disconnect=0x8000;
 		desc.len=Memory.SRAMMask+1;

From 73a4e459d151b8153915453756aae3786e6a41b3 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 19:28:56 +0200
Subject: [PATCH 09/19] Allow larger SRAM in HiROM. .len is enough to trim the
 size down properly anyways.

---
 memmap.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/memmap.cpp b/memmap.cpp
index bc32c933..96e9fdfe 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2936,7 +2936,7 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	if (type==MAP_HIROM_SRAM || type==MAP_RONLY_SRAM)
 	{
 		desc.ptr=Memory.SRAM;
-		desc.disconnect=0xF8E000;
+		desc.disconnect=0x00E000;
 		desc.len=Memory.SRAMMask+1;
 		S9xAppendMapping(&desc);
 	}

From d3ecdd353414c4fce283227d7b9831f24bf7cc47 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 20:02:49 +0200
Subject: [PATCH 10/19] Fix rather creepy crash. Merge those 64 mappings into
 one.

---
 libretro/libretro.cpp |   9 +-
 memmap.cpp            | 192 +++++++++++++++++++++++++-----------------
 memmap.h              |  12 +--
 3 files changed, 128 insertions(+), 85 deletions(-)

diff --git a/libretro/libretro.cpp b/libretro/libretro.cpp
index 7d4bfa56..6a79b8cd 100644
--- a/libretro/libretro.cpp
+++ b/libretro/libretro.cpp
@@ -320,12 +320,13 @@ void retro_cheat_set(unsigned index, bool enabled, const char *code)
    S9xApplyCheats();
 }
 
-static struct retro_memory_descriptor memorydesc[64];
+#define MAX_MAPS 256
+static struct retro_memory_descriptor memorydesc[MAX_MAPS];
 static unsigned memorydesc_c;
 void S9xAppendMapping(struct retro_memory_descriptor * desc)
 {
 	//do it backwards - snes9x defines the last one to win, while we define the first one to win
-	memcpy(&memorydesc[64 - (++memorydesc_c)], desc, sizeof(struct retro_memory_descriptor));
+	memcpy(&memorydesc[MAX_MAPS - (++memorydesc_c)], desc, sizeof(struct retro_memory_descriptor));
 }
 
 bool retro_load_game(const struct retro_game_info *game)
@@ -340,7 +341,7 @@ bool retro_load_game(const struct retro_game_info *game)
    if (!rom_loaded && log_cb)
       log_cb(RETRO_LOG_ERROR, "[libretro]: Rom loading failed...\n");
    
-   struct retro_memory_map map={ memorydesc+64-memorydesc_c, memorydesc_c };
+   struct retro_memory_map map={ memorydesc+MAX_MAPS-memorydesc_c, memorydesc_c };
    if (rom_loaded) environ_cb(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &map);
    
    return rom_loaded;
@@ -396,7 +397,7 @@ bool retro_load_game_special(unsigned game_type,
        break;
   }
   
-  struct retro_memory_map map={ memorydesc+64-memorydesc_c, memorydesc_c };
+  struct retro_memory_map map={ memorydesc+MAX_MAPS-memorydesc_c, memorydesc_c };
   if (rom_loaded) environ_cb(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &map);
 
   return rom_loaded;
diff --git a/memmap.cpp b/memmap.cpp
index 96e9fdfe..d853d934 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2763,7 +2763,7 @@ uint32 CMemory::map_mirror (uint32 size, uint32 pos)
 		return (mask + map_mirror(size - mask, pos - mask));
 }
 
-void CMemory::map_lorom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size)
+void CMemory::map_lorom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, bool auto_export_map)
 {
 	uint32	c, i, p, addr;
 
@@ -2780,18 +2780,21 @@ void CMemory::map_lorom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	}
 
 #ifdef __LIBRETRO__
-	struct retro_memory_descriptor desc = {0};
-	desc.flags=RETRO_MEMDESC_CONST;
-	desc.ptr=ROM;
-	desc.start=bank_s<<16 | addr_s;
-	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-	desc.disconnect=0x8000;
-	desc.len=size;
-	S9xAppendMapping(&desc);
+	if (auto_export_map)
+	{
+		struct retro_memory_descriptor desc = {0};
+		desc.flags=RETRO_MEMDESC_CONST;
+		desc.ptr=ROM;
+		desc.start=bank_s<<16 | addr_s;
+		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+		desc.disconnect=0x8000;
+		desc.len=size;
+		S9xAppendMapping(&desc);
+	}
 #endif
 }
 
-void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size)
+void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, bool auto_export_map)
 {
 	uint32	c, i, p, addr;
 
@@ -2808,17 +2811,20 @@ void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 	}
 
 #ifdef __LIBRETRO__
-	struct retro_memory_descriptor desc = {0};
-	desc.flags=RETRO_MEMDESC_CONST;
-	desc.ptr=ROM;
-	desc.start=bank_s<<16 | addr_s;
-	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-	desc.len=size;
-	S9xAppendMapping(&desc);
+	if (auto_export_map)
+	{
+		struct retro_memory_descriptor desc = {0};
+		desc.flags=RETRO_MEMDESC_CONST;
+		desc.ptr=ROM;
+		desc.start=bank_s<<16 | addr_s;
+		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+		desc.len=size;
+		S9xAppendMapping(&desc);
+	}
 #endif
 }
 
-void CMemory::map_lorom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, uint32 offset)
+void CMemory::map_lorom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, uint32 offset, bool auto_export_map)
 {
 	uint32	c, i, p, addr;
 
@@ -2835,19 +2841,22 @@ void CMemory::map_lorom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 	}
 
 #ifdef __LIBRETRO__
-	struct retro_memory_descriptor desc = {0};
-	desc.flags=RETRO_MEMDESC_CONST;
-	desc.ptr=ROM;
-	desc.offset=offset;
-	desc.start=bank_s<<16 | addr_s;
-	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-	desc.disconnect=0x8000;
-	desc.len=size;
-	S9xAppendMapping(&desc);
+	if (auto_export_map)
+	{
+		struct retro_memory_descriptor desc = {0};
+		desc.flags=RETRO_MEMDESC_CONST;
+		desc.ptr=ROM;
+		desc.offset=offset;
+		desc.start=bank_s<<16 | addr_s;
+		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+		desc.disconnect=0x8000;
+		desc.len=size;
+		S9xAppendMapping(&desc);
+	}
 #endif
 }
 
-void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, uint32 offset)
+void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint32 size, uint32 offset, bool auto_export_map)
 {
 	uint32	c, i, p, addr;
 
@@ -2863,18 +2872,21 @@ void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 		}
 	}
 #ifdef __LIBRETRO__
-	struct retro_memory_descriptor desc = {0};
-	desc.flags=RETRO_MEMDESC_CONST;
-	desc.ptr=ROM;
-	desc.offset=offset;
-	desc.start=bank_s<<16 | addr_s;
-	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-	desc.len=size;
-	S9xAppendMapping(&desc);
+	if (auto_export_map)
+	{
+		struct retro_memory_descriptor desc = {0};
+		desc.flags=RETRO_MEMDESC_CONST;
+		desc.ptr=ROM;
+		desc.offset=offset;
+		desc.start=bank_s<<16 | addr_s;
+		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+		desc.len=size;
+		S9xAppendMapping(&desc);
+	}
 #endif
 }
 
-void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint8 *data)
+void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, uint8 *data, bool auto_export_map)
 {
 	uint32	c, i, p;
 
@@ -2889,15 +2901,18 @@ void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 		}
 	}
 #ifdef __LIBRETRO__
-	struct retro_memory_descriptor desc = {0};
-	desc.ptr=data;
-	desc.start=bank_s<<16 | addr_s;
-	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-	S9xAppendMapping(&desc);
+	if (auto_export_map)
+	{
+		struct retro_memory_descriptor desc = {0};
+		desc.ptr=data;
+		desc.start=bank_s<<16 | addr_s;
+		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+		S9xAppendMapping(&desc);
+	}
 #endif
 }
 
-void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, int index, int type)
+void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 addr_e, int index, int type, bool auto_export_map)
 {
 	uint32	c, i, p;
 	bool8	isROM, isRAM;
@@ -2916,35 +2931,38 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 		}
 	}
 #ifdef __LIBRETRO__
-	struct retro_memory_descriptor desc = {0};
-	desc.start=bank_s<<16 | addr_s;
-	desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-	if (type==MAP_LOROM_SRAM || type==MAP_SA1RAM)
+	if (auto_export_map)
 	{
-		desc.ptr=Memory.SRAM;
-		desc.disconnect=0x8000;
-		desc.len=Memory.SRAMMask+1;
-		S9xAppendMapping(&desc);
-	}
-	if (type==MAP_LOROM_SRAM_B)
-	{
-		desc.ptr=Multi.sramB;
-		desc.disconnect=0x8000;
-		desc.len=Multi.sramMaskB+1;
-		S9xAppendMapping(&desc);
-	}
-	if (type==MAP_HIROM_SRAM || type==MAP_RONLY_SRAM)
-	{
-		desc.ptr=Memory.SRAM;
-		desc.disconnect=0x00E000;
-		desc.len=Memory.SRAMMask+1;
-		S9xAppendMapping(&desc);
-	}
-	if (type==MAP_BWRAM)
-	{
-		desc.ptr=Memory.BWRAM;
-		desc.disconnect=0xFFE000;
-		S9xAppendMapping(&desc);
+		struct retro_memory_descriptor desc = {0};
+		desc.start=bank_s<<16 | addr_s;
+		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+		if (type==MAP_LOROM_SRAM || type==MAP_SA1RAM)
+		{
+			desc.ptr=Memory.SRAM;
+			desc.disconnect=0x8000;
+			desc.len=Memory.SRAMMask+1;
+			S9xAppendMapping(&desc);
+		}
+		if (type==MAP_LOROM_SRAM_B)
+		{
+			desc.ptr=Multi.sramB;
+			desc.disconnect=0x8000;
+			desc.len=Multi.sramMaskB+1;
+			S9xAppendMapping(&desc);
+		}
+		if (type==MAP_HIROM_SRAM || type==MAP_RONLY_SRAM)
+		{
+			desc.ptr=Memory.SRAM;
+			desc.disconnect=0x00E000;
+			desc.len=Memory.SRAMMask+1;
+			S9xAppendMapping(&desc);
+		}
+		if (type==MAP_BWRAM)
+		{
+			desc.ptr=Memory.BWRAM;
+			desc.disconnect=0xFFE000;
+			S9xAppendMapping(&desc);
+		}
 	}
 #endif
 }
@@ -3303,7 +3321,19 @@ void CMemory::Map_SA1LoROMMap (void)
 	map_index(0x80, 0xbf, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
 
 	for (int c = 0x40; c < 0x80; c++)
-		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000);
+		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000, false);
+
+#ifdef __LIBRETRO__
+	if (auto_export_map)
+	{
+		struct retro_memory_descriptor desc = {0};
+		desc.ptr=SRAM;
+		desc.start=0x400000;
+		desc.select=0xC00000;
+		desc.disconnect=0xFE0000;
+		S9xAppendMapping(&desc);
+	}
+#endif
 
 	map_WRAM();
 
@@ -3339,13 +3369,25 @@ void CMemory::Map_GNEXTSA1LoROMMap (void)
 
 	map_hirom_offset(0xc0, 0xff, 0x0000, 0xffff, Multi.cartSizeA, Multi.cartOffsetA);
 
-	map_space(0x00, 0x3f, 0x3000, 0x3fff, FillRAM);
 	map_space(0x80, 0xbf, 0x3000, 0x3fff, FillRAM);
-	map_index(0x00, 0x3f, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
+	map_space(0x00, 0x3f, 0x3000, 0x3fff, FillRAM);
 	map_index(0x80, 0xbf, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
+	map_index(0x00, 0x3f, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
 
 	for (int c = 0x40; c < 0x80; c++)
-		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000);
+		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000, false);
+
+#ifdef __LIBRETRO__
+	if (auto_export_map)
+	{
+		struct retro_memory_descriptor desc = {0};
+		desc.ptr=SRAM;
+		desc.start=0x400000;
+		desc.select=0xC00000;
+		desc.disconnect=0xFE0000;
+		S9xAppendMapping(&desc);
+	}
+#endif
 
 	// FIXME: untested!
 	map_hirom_offset(0x70, 0x7f, 0x0000, 0xffff, Multi.cartSizeB, Multi.cartOffsetB);
diff --git a/memmap.h b/memmap.h
index 0f943542..0ca1245d 100644
--- a/memmap.h
+++ b/memmap.h
@@ -295,12 +295,12 @@ struct CMemory
 	void	InitROM (void);
 
 	uint32	map_mirror (uint32, uint32);
-	void	map_lorom (uint32, uint32, uint32, uint32, uint32);
-	void	map_hirom (uint32, uint32, uint32, uint32, uint32);
-	void	map_lorom_offset (uint32, uint32, uint32, uint32, uint32, uint32);
-	void	map_hirom_offset (uint32, uint32, uint32, uint32, uint32, uint32);
-	void	map_space (uint32, uint32, uint32, uint32, uint8 *);
-	void	map_index (uint32, uint32, uint32, uint32, int, int);
+	void	map_lorom (uint32, uint32, uint32, uint32, uint32, bool = true);
+	void	map_hirom (uint32, uint32, uint32, uint32, uint32, bool = true);
+	void	map_lorom_offset (uint32, uint32, uint32, uint32, uint32, uint32, bool = true);
+	void	map_hirom_offset (uint32, uint32, uint32, uint32, uint32, uint32, bool = true);
+	void	map_space (uint32, uint32, uint32, uint32, uint8 *, bool = true);
+	void	map_index (uint32, uint32, uint32, uint32, int, int, bool = true);
 	void	map_System (void);
 	void	map_WRAM (void);
 	void	map_LoROMSRAM (void);

From dbd233128201991002b0caf1a2e1f83b00dbe416 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 20:28:19 +0200
Subject: [PATCH 11/19] Fix bad copypasta.

---
 memmap.cpp | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index d853d934..6cf4d936 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -3324,15 +3324,12 @@ void CMemory::Map_SA1LoROMMap (void)
 		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000, false);
 
 #ifdef __LIBRETRO__
-	if (auto_export_map)
-	{
-		struct retro_memory_descriptor desc = {0};
-		desc.ptr=SRAM;
-		desc.start=0x400000;
-		desc.select=0xC00000;
-		desc.disconnect=0xFE0000;
-		S9xAppendMapping(&desc);
-	}
+	struct retro_memory_descriptor desc = {0};
+	desc.ptr=SRAM;
+	desc.start=0x400000;
+	desc.select=0xC00000;
+	desc.disconnect=0xFE0000;
+	S9xAppendMapping(&desc);
 #endif
 
 	map_WRAM();
@@ -3378,15 +3375,12 @@ void CMemory::Map_GNEXTSA1LoROMMap (void)
 		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000, false);
 
 #ifdef __LIBRETRO__
-	if (auto_export_map)
-	{
-		struct retro_memory_descriptor desc = {0};
-		desc.ptr=SRAM;
-		desc.start=0x400000;
-		desc.select=0xC00000;
-		desc.disconnect=0xFE0000;
-		S9xAppendMapping(&desc);
-	}
+	struct retro_memory_descriptor desc = {0};
+	desc.ptr=SRAM;
+	desc.start=0x400000;
+	desc.select=0xC00000;
+	desc.disconnect=0xFE0000;
+	S9xAppendMapping(&desc);
 #endif
 
 	// FIXME: untested!

From 2a9fbf0f24a566fc80bc3f5a02833c084c8dd937 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 20:53:27 +0200
Subject: [PATCH 12/19] Disconnect the bank byte from WRAM. It shouldn't be
 there.

---
 memmap.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/memmap.cpp b/memmap.cpp
index 6cf4d936..d3684d94 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2907,6 +2907,7 @@ void CMemory::map_space (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 		desc.ptr=data;
 		desc.start=bank_s<<16 | addr_s;
 		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
+		desc.disconnect=0xFF0000;
 		S9xAppendMapping(&desc);
 	}
 #endif

From 0fcda51be41219fcef6ce70ba08b2c95fb859398 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 21:17:07 +0200
Subject: [PATCH 13/19] Map some of those backwards, so the lower address shows
 up first in the descriptors.

---
 memmap.cpp | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index d3684d94..132de475 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2988,14 +2988,14 @@ void CMemory::map_WRAM (void)
 
 void CMemory::map_LoROMSRAM (void)
 {
-	map_index(0x70, 0x7f, 0x0000, 0x7fff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
 	map_index(0xf0, 0xff, 0x0000, 0x7fff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
+	map_index(0x70, 0x7f, 0x0000, 0x7fff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
 }
 
 void CMemory::map_HiROMSRAM (void)
 {
-	map_index(0x20, 0x3f, 0x6000, 0x7fff, MAP_HIROM_SRAM, MAP_TYPE_RAM);
 	map_index(0xa0, 0xbf, 0x6000, 0x7fff, MAP_HIROM_SRAM, MAP_TYPE_RAM);
+	map_index(0x20, 0x3f, 0x6000, 0x7fff, MAP_HIROM_SRAM, MAP_TYPE_RAM);
 }
 
 void CMemory::map_DSP (void)
@@ -3126,8 +3126,8 @@ void CMemory::Map_NoMAD1LoROMMap (void)
 	map_lorom(0x80, 0xbf, 0x8000, 0xffff, CalculatedSize);
 	map_lorom(0xc0, 0xff, 0x0000, 0xffff, CalculatedSize);
 
-	map_index(0x70, 0x7f, 0x0000, 0xffff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
 	map_index(0xf0, 0xff, 0x0000, 0xffff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
+	map_index(0x70, 0x7f, 0x0000, 0xffff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
 
 	map_WRAM();
 
@@ -3178,10 +3178,10 @@ void CMemory::Map_SRAM512KLoROMMap (void)
 	map_lorom(0x80, 0xbf, 0x8000, 0xffff, CalculatedSize);
 	map_lorom(0xc0, 0xff, 0x0000, 0xffff, CalculatedSize);
 
-	map_space(0x70, 0x70, 0x0000, 0xffff, SRAM);
-	map_space(0x71, 0x71, 0x0000, 0xffff, SRAM + 0x8000);
-	map_space(0x72, 0x72, 0x0000, 0xffff, SRAM + 0x10000);
 	map_space(0x73, 0x73, 0x0000, 0xffff, SRAM + 0x18000);
+	map_space(0x72, 0x72, 0x0000, 0xffff, SRAM + 0x10000);
+	map_space(0x71, 0x71, 0x0000, 0xffff, SRAM + 0x8000);
+	map_space(0x70, 0x70, 0x0000, 0xffff, SRAM);
 
 	map_WRAM();
 
@@ -3202,14 +3202,14 @@ void CMemory::Map_SufamiTurboLoROMMap (void)
 
 	if (Multi.sramSizeA)
 	{
-		map_index(0x60, 0x63, 0x8000, 0xffff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
 		map_index(0xe0, 0xe3, 0x8000, 0xffff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
+		map_index(0x60, 0x63, 0x8000, 0xffff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
 	}
 
 	if (Multi.sramSizeB)
 	{
-		map_index(0x70, 0x73, 0x8000, 0xffff, MAP_LOROM_SRAM_B, MAP_TYPE_RAM);
 		map_index(0xf0, 0xf3, 0x8000, 0xffff, MAP_LOROM_SRAM_B, MAP_TYPE_RAM);
+		map_index(0x70, 0x73, 0x8000, 0xffff, MAP_LOROM_SRAM_B, MAP_TYPE_RAM);
 	}
 
 	map_WRAM();
@@ -3233,8 +3233,8 @@ void CMemory::Map_SufamiTurboPseudoLoROMMap (void)
 	// I don't care :P
 	map_space(0x60, 0x63, 0x8000, 0xffff, SRAM - 0x8000);
 	map_space(0xe0, 0xe3, 0x8000, 0xffff, SRAM - 0x8000);
-	map_space(0x70, 0x73, 0x8000, 0xffff, SRAM + 0x4000 - 0x8000);
-	map_space(0xf0, 0xf3, 0x8000, 0xffff, SRAM + 0x4000 - 0x8000);
+	map_space(0x70, 0x73, 0x8000, 0xffff, SRAM + 0x4000 - 0x8000, false);
+	map_space(0xf0, 0xf3, 0x8000, 0xffff, SRAM + 0x4000 - 0x8000, false);
 
 	map_WRAM();
 
@@ -3262,8 +3262,8 @@ void CMemory::Map_SuperFXLoROMMap (void)
 
 	map_space(0x00, 0x3f, 0x6000, 0x7fff, SRAM - 0x6000);
 	map_space(0x80, 0xbf, 0x6000, 0x7fff, SRAM - 0x6000);
-	map_space(0x70, 0x70, 0x0000, 0xffff, SRAM);
 	map_space(0x71, 0x71, 0x0000, 0xffff, SRAM + 0x10000);
+	map_space(0x70, 0x70, 0x0000, 0xffff, SRAM);
 
 	map_WRAM();
 
@@ -3316,10 +3316,10 @@ void CMemory::Map_SA1LoROMMap (void)
 
 	map_hirom_offset(0xc0, 0xff, 0x0000, 0xffff, CalculatedSize, 0);
 
-	map_space(0x00, 0x3f, 0x3000, 0x3fff, FillRAM);
 	map_space(0x80, 0xbf, 0x3000, 0x3fff, FillRAM);
-	map_index(0x00, 0x3f, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
+	map_space(0x00, 0x3f, 0x3000, 0x3fff, FillRAM);
 	map_index(0x80, 0xbf, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
+	map_index(0x00, 0x3f, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
 
 	for (int c = 0x40; c < 0x80; c++)
 		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000, false);

From dc18bca804f8636c433e8a0d7d44308921e0a731 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 21:23:14 +0200
Subject: [PATCH 14/19] FillRAM (I-RAM) is probably more important than BW-RAM.

---
 memmap.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index 132de475..ad11ca44 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -3316,10 +3316,10 @@ void CMemory::Map_SA1LoROMMap (void)
 
 	map_hirom_offset(0xc0, 0xff, 0x0000, 0xffff, CalculatedSize, 0);
 
-	map_space(0x80, 0xbf, 0x3000, 0x3fff, FillRAM);
-	map_space(0x00, 0x3f, 0x3000, 0x3fff, FillRAM);
 	map_index(0x80, 0xbf, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
 	map_index(0x00, 0x3f, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
+	map_space(0x80, 0xbf, 0x3000, 0x3fff, FillRAM);
+	map_space(0x00, 0x3f, 0x3000, 0x3fff, FillRAM);
 
 	for (int c = 0x40; c < 0x80; c++)
 		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000, false);

From 2a65558d516f97266148354b7b7f9f1d7df40318 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 21:27:12 +0200
Subject: [PATCH 15/19] Fix this. Apparently this one is variable.

---
 memmap.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index ad11ca44..ce8165d3 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2960,8 +2960,8 @@ void CMemory::map_index (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 		}
 		if (type==MAP_BWRAM)
 		{
-			desc.ptr=Memory.BWRAM;
-			desc.disconnect=0xFFE000;
+			desc.ptr=Memory.SRAM;//this one varies, but we can't use variable maps in this system.
+			desc.disconnect=0xFFE000;//It's the same as SRAM, anyways. Let's point it to there and let the front ignore it.
 			S9xAppendMapping(&desc);
 		}
 	}
@@ -3316,10 +3316,10 @@ void CMemory::Map_SA1LoROMMap (void)
 
 	map_hirom_offset(0xc0, 0xff, 0x0000, 0xffff, CalculatedSize, 0);
 
-	map_index(0x80, 0xbf, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
-	map_index(0x00, 0x3f, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
 	map_space(0x80, 0xbf, 0x3000, 0x3fff, FillRAM);
 	map_space(0x00, 0x3f, 0x3000, 0x3fff, FillRAM);
+	map_index(0x80, 0xbf, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
+	map_index(0x00, 0x3f, 0x6000, 0x7fff, MAP_BWRAM, MAP_TYPE_I_O);
 
 	for (int c = 0x40; c < 0x80; c++)
 		map_space(c, c, 0x0000, 0xffff, SRAM + (c & 1) * 0x10000, false);

From 3ba8c3bb2d58c55b569ca6746204cf90e445d970 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Wed, 28 May 2014 22:44:52 +0200
Subject: [PATCH 16/19] Trim trailing spaces.

---
 libretro/libretro.cpp |  2 +-
 libretro/libretro.h   | 21 ++++++++++-----------
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/libretro/libretro.cpp b/libretro/libretro.cpp
index 6a79b8cd..c9b56ea4 100644
--- a/libretro/libretro.cpp
+++ b/libretro/libretro.cpp
@@ -320,7 +320,7 @@ void retro_cheat_set(unsigned index, bool enabled, const char *code)
    S9xApplyCheats();
 }
 
-#define MAX_MAPS 256
+#define MAX_MAPS 32
 static struct retro_memory_descriptor memorydesc[MAX_MAPS];
 static unsigned memorydesc_c;
 void S9xAppendMapping(struct retro_memory_descriptor * desc)
diff --git a/libretro/libretro.h b/libretro/libretro.h
index e63aebb2..6de87836 100755
--- a/libretro/libretro.h
+++ b/libretro/libretro.h
@@ -642,12 +642,11 @@ enum retro_mod
                                            // Even if special device types are set in the libretro core, libretro should only poll input based on the base input device types.
 #define RETRO_ENVIRONMENT_SET_MEMORY_MAPS (36 | RETRO_ENVIRONMENT_EXPERIMENTAL)
                                            // const struct retro_memory_map * --
-                                           // This environment call lets a libretro core tell the frontend about the memory maps
-                                           // emulated by this core. This can be used to implement, for example, cheats.
+                                           // This environment call lets a libretro core tell the frontend about the memory maps this
+                                           // core emulates. This can be used to implement, for example, cheats in a core-agnostic way.
                                            //
                                            // Should only be used by emulators; it doesn't make much sense for anything else.
-                                           //
-                                           // It is highly recommended to expose all relevant pointers through retro_get_memory_* as well.
+                                           // It is recommended to expose all relevant pointers through retro_get_memory_* as well.
                                            //
                                            // Can be called from retro_init and retro_load_game.
                                            //
@@ -657,7 +656,7 @@ enum retro_mod
 #define RETRO_MEMDESC_ALIGNED   (1 << 2) // All memory access in this area is aligned to their own size, and no non-power-of-two sized data exists.
 struct retro_memory_descriptor {
    uint64_t flags;
-   
+
    //Pointer to the start of the relevant ROM or RAM chip.
    //It's strongly recommended to use 'offset' if possible, rather than doing math on the pointer.
    //If the same byte is mapped my multiple descriptors, their descriptors must have the same pointer.
@@ -666,28 +665,28 @@ struct retro_memory_descriptor {
    //It's recommended to minimize the number of descriptors if possible, but not mandatory.
    void * ptr;
    size_t offset;
-   
+
    //This is the location in the emulated address space where the mapping starts.
    size_t start;
-   
+
    //Which bits must be same as in 'start' for this mapping to apply.
    //The first memory descriptor to claim a certain byte is the one that applies.
    //A bit which is set in 'start' must also be set in this.
    //Can be zero, in which case each byte is assumed mapped exactly once. In this case, 'len' must be a power of two.
    size_t select;
-   
+
    //If this is nonzero, the set bits are assumed not connected to the memory chip's address pins.
    size_t disconnect;
-   
+
    //This one tells the size of the current memory area.
    //If, after start+disconnect are applied, the address is higher than this, the highest bit of the address is cleared.
    //If the address is still too high, the next highest bit is cleared.
    //Can be zero, in which case it's assumed to be infinite (as limited by 'select' and 'disconnect').
    size_t len;
-   
+
    //To go from emulated address to physical address, the following order applies:
    //Subtract 'start', pick off 'disconnect', apply 'len', add 'offset'.
-   
+
    //The address space name must consist of only a-zA-Z0-9_-, should be as short as feasible (maximum length is 8 plus the NUL),
    // and may not be any other address space plus one or more 0-9A-F at the end.
    //However, multiple memory descriptors for the same address space is allowed, and the address

From 5e2b73d26a7ec472b6341ba26e7d6f0288a81abe Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Fri, 30 May 2014 11:57:44 +0200
Subject: [PATCH 17/19] Add minimum size flags.

---
 libretro/libretro.h | 11 ++++++++---
 memmap.cpp          |  1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/libretro/libretro.h b/libretro/libretro.h
index 6de87836..c6ac4c62 100755
--- a/libretro/libretro.h
+++ b/libretro/libretro.h
@@ -651,9 +651,14 @@ enum retro_mod
                                            // Can be called from retro_init and retro_load_game.
                                            //
 
-#define RETRO_MEMDESC_CONST     (1 << 0) // The frontend will never change this memory area once retro_load_game has returned.
-#define RETRO_MEMDESC_BIGENDIAN (1 << 1) // The memory area contains big endian data. Default is little endian.
-#define RETRO_MEMDESC_ALIGNED   (1 << 2) // All memory access in this area is aligned to their own size, and no non-power-of-two sized data exists.
+#define RETRO_MEMDESC_CONST     (1 << 0)  // The frontend will never change this memory area once retro_load_game has returned.
+#define RETRO_MEMDESC_BIGENDIAN (1 << 1)  // The memory area contains big endian data. Default is little endian.
+#define RETRO_MEMDESC_ALIGN_2   (1 << 16) // All memory access in this area is aligned to their own size, or 2, whichever is smaller.
+#define RETRO_MEMDESC_ALIGN_4   (2 << 16)
+#define RETRO_MEMDESC_ALIGN_8   (3 << 16)
+#define RETRO_MEMDESC_MINSIZE_2 (1 << 24) // All memory in this region is accessed at least 2 bytes at the time.
+#define RETRO_MEMDESC_MINSIZE_4 (2 << 24)
+#define RETRO_MEMDESC_MINSIZE_8 (3 << 24)
 struct retro_memory_descriptor {
    uint64_t flags;
 
diff --git a/memmap.cpp b/memmap.cpp
index ce8165d3..911c6182 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -3330,6 +3330,7 @@ void CMemory::Map_SA1LoROMMap (void)
 	desc.start=0x400000;
 	desc.select=0xC00000;
 	desc.disconnect=0xFE0000;
+	desc.len=0x20000;
 	S9xAppendMapping(&desc);
 #endif
 

From 588135d4aae75bb35f6dba1aeb4ec19b74b36509 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Fri, 30 May 2014 12:12:00 +0200
Subject: [PATCH 18/19] This one doesn't really look right.

---
 memmap.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index 911c6182..771dd06e 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2816,9 +2816,10 @@ void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 		struct retro_memory_descriptor desc = {0};
 		desc.flags=RETRO_MEMDESC_CONST;
 		desc.ptr=ROM;
+		desc.offset=map_mirror(size, bank_s<<16 | addr_s);
 		desc.start=bank_s<<16 | addr_s;
 		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
-		desc.len=size;
+		desc.len=size - desc.offset;
 		S9xAppendMapping(&desc);
 	}
 #endif
@@ -2877,7 +2878,7 @@ void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 		struct retro_memory_descriptor desc = {0};
 		desc.flags=RETRO_MEMDESC_CONST;
 		desc.ptr=ROM;
-		desc.offset=offset;
+		desc.offset=map_mirror(size, offset + (bank_s<<16 | addr_s));
 		desc.start=bank_s<<16 | addr_s;
 		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
 		desc.len=size;

From 5df4ad7082cb17fccbc078af63115baf75a0fa62 Mon Sep 17 00:00:00 2001
From: Alcaro <floating@muncher.se>
Date: Fri, 30 May 2014 12:26:30 +0200
Subject: [PATCH 19/19] snes9x's internal memory maps are quite weird. I think
 this is the right way to handle hirom.

---
 memmap.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/memmap.cpp b/memmap.cpp
index 771dd06e..cb0b35b3 100644
--- a/memmap.cpp
+++ b/memmap.cpp
@@ -2816,7 +2816,7 @@ void CMemory::map_hirom (uint32 bank_s, uint32 bank_e, uint32 addr_s, uint32 add
 		struct retro_memory_descriptor desc = {0};
 		desc.flags=RETRO_MEMDESC_CONST;
 		desc.ptr=ROM;
-		desc.offset=map_mirror(size, bank_s<<16 | addr_s);
+		desc.offset=map_mirror(size, addr_s);
 		desc.start=bank_s<<16 | addr_s;
 		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
 		desc.len=size - desc.offset;
@@ -2878,7 +2878,7 @@ void CMemory::map_hirom_offset (uint32 bank_s, uint32 bank_e, uint32 addr_s, uin
 		struct retro_memory_descriptor desc = {0};
 		desc.flags=RETRO_MEMDESC_CONST;
 		desc.ptr=ROM;
-		desc.offset=map_mirror(size, offset + (bank_s<<16 | addr_s));
+		desc.offset=map_mirror(size, offset + addr_s);
 		desc.start=bank_s<<16 | addr_s;
 		desc.select=(bank_s<<16 | addr_s) ^ (bank_e<<16 | addr_e) ^ 0xFFFFFF;
 		desc.len=size;