From d854ca66f55d2bba536bcee7b3a163ce5650c3d9 Mon Sep 17 00:00:00 2001
From: Andre Leiradella <andre@leiradella.com>
Date: Thu, 13 Jul 2017 00:23:01 +0100
Subject: [PATCH] Memory map all the available RAM

---
 src/cheat.c                     |  5 ++++-
 src/cheat.h                     |  2 ++
 src/drivers/libretro/libretro.c | 24 +++++++++++++++++++++++-
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/cheat.c b/src/cheat.c
index 79be91f..1bdd82c 100644
--- a/src/cheat.c
+++ b/src/cheat.c
@@ -32,6 +32,7 @@
 #include "fceu-memory.h"
 
 static uint8 *CheatRPtrs[64];
+uint8 *MMapPtrs[64];
 
 void FCEU_CheatResetRAM(void) {
 	int x;
@@ -44,8 +45,10 @@ void FCEU_CheatAddRAM(int s, uint32 A, uint8 *p) {
 	uint32 AB = A >> 10;
 	int x;
 
-	for (x = s - 1; x >= 0; x--)
+	for (x = s - 1; x >= 0; x--) {
 		CheatRPtrs[AB + x] = p - A;
+		MMapPtrs[AB + x] = p + 1024 * x;
+	}
 }
 
 
diff --git a/src/cheat.h b/src/cheat.h
index 824e513..9081c96 100644
--- a/src/cheat.h
+++ b/src/cheat.h
@@ -1,6 +1,8 @@
 #ifndef _FCEU_CHEAT_H
 #define _FCEU_CHEAT_H
 
+extern uint8 *MMapPtrs[64];
+
 void FCEU_CheatResetRAM(void);
 void FCEU_CheatAddRAM(int s, uint32 A, uint8 *p);
 
diff --git a/src/drivers/libretro/libretro.c b/src/drivers/libretro/libretro.c
index 7c3a1c0..b0f42d8 100644
--- a/src/drivers/libretro/libretro.c
+++ b/src/drivers/libretro/libretro.c
@@ -1644,7 +1644,7 @@ extern uint32_t iNESGameCRC32;
 
 bool retro_load_game(const struct retro_game_info *game)
 {
-   unsigned i;
+   unsigned i, j;
    char* dir=NULL;
    char* sav_dir=NULL;
    size_t fourscore_len = sizeof(fourscore_db_list)   / sizeof(fourscore_db_list[0]);
@@ -1701,6 +1701,9 @@ bool retro_load_game(const struct retro_game_info *game)
       { 0 },
    };
 
+   struct retro_memory_descriptor descs[64];
+   struct retro_memory_map        mmaps;
+
    if (!game)
       return false;
 
@@ -1766,6 +1769,25 @@ bool retro_load_game(const struct retro_game_info *game)
       }
    }
 
+   memset(descs, 0, sizeof(descs));
+   i = 0;
+
+   for (j = 0; j < 64; j++)
+   {
+      if (MMapPtrs[j] != NULL)
+      {
+         descs[i].ptr    = MMapPtrs[j];
+         descs[i].start  = j * 1024;
+         descs[i].len    = 1024;
+         descs[i].select = 0;
+         i++;
+      }
+   }
+
+   mmaps.descriptors = descs;
+   mmaps.num_descriptors = i;
+   environ_cb(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &mmaps);
+ 
    return true;
 }