Add 3DS memory map

The "real" addresses set here are based on 3DS virtual memory addresses, with this memory map intended to map 1:1 with 3DS userland virtual memory

Unsure if this would end up being desirable in practice. This has the benefit of making points map 1:1 to RetroAchievements memory space (which is a huge win given how pointer heavy 3DS games will be and the disjointed mess that "real" memory lies in the memory map). This will, however, balloon the memory space to search in for developers. BizHawk (the current 3DS RetroAchievements capable emulator), as an implementation detail, also slightly suffers for the achievement runtime as it will allocate 1GiB here for a memory block LUT; this is an implementation detail, however, just due to being a multi-system emulator, a standalone emulator wouldn't have such, and even so 1GiB of memory is relatively free for any machine that can handle 3DS emulation anyways.

A different memory map could potentially be made which only covers the "real" memory spaces, but doing so will still have a large amount of memory mapped (definitely more than 256MiB, the size of the New 3DS's FCRAM), and will be much harder for the current achievements implementation to handle pointers (given the reported problems with even handling MEM1/MEM2 on the Wii).

Author: CasualPokePlayer

src/rcheevos/consoleinfo.c

@@ -759,6 +759,29 @@ static const rc_memory_region_t _rc_memory_regions_nintendo_dsi[] = {
 };
 static const rc_memory_regions_t rc_memory_regions_nintendo_dsi = { _rc_memory_regions_nintendo_dsi, 2 };
 
+/* ===== Nintendo 3DS ===== */
+/* https://www.3dbrew.org/wiki/Memory_layout#ARM11_User-land_memory_regions */
+static const rc_memory_region_t _rc_memory_regions_nintendo_3ds[] = {
+    { 0x00000000U, 0x000FFFFFU, 0x00000000U, RC_MEMORY_TYPE_UNUSED, "" },
+    { 0x00100000U, 0x03FFFFFFU, 0x00100000U, RC_MEMORY_TYPE_SYSTEM_RAM, "Code Binary" }, /* Usual place where ExeFS .code is loaded */
+    { 0x04000000U, 0x07FFFFFFU, 0x04000000U, RC_MEMORY_TYPE_HARDWARE_CONTROLLER, "IPC Buffers" },
+    { 0x08000000U, 0x0FFFFFFFU, 0x08000000U, RC_MEMORY_TYPE_SYSTEM_RAM, "Regular Heap and Stack" },
+    { 0x10000000U, 0x13FFFFFFU, 0x10000000U, RC_MEMORY_TYPE_HARDWARE_CONTROLLER, "Shared Memory" },
+    { 0x14000000U, 0x1BFFFFFFU, 0x14000000U, RC_MEMORY_TYPE_SYSTEM_RAM, "Linear Heap" }, /* Sometimes ExeFS .code is actually loaded here */
+    { 0x1C000000U, 0x1E7FFFFFU, 0x1C000000U, RC_MEMORY_TYPE_UNUSED, "" },
+    { 0x1E800000U, 0x1EBFFFFFU, 0x1E800000U, RC_MEMORY_TYPE_SYSTEM_RAM, "New 3DS Memory" },
+    { 0x1EC00000U, 0x1EFFFFFFU, 0x1EC00000U, RC_MEMORY_TYPE_HARDWARE_CONTROLLER, "I/O Registers" },
+    { 0x1F000000U, 0x1F5FFFFFU, 0x1F000000U, RC_MEMORY_TYPE_VIDEO_RAM, "VRAM" },
+    { 0x1F600000U, 0x1FEFFFFFU, 0x1F600000U, RC_MEMORY_TYPE_UNUSED, "" },
+    { 0x1FF00000U, 0x1FF7FFFFU, 0x1FF00000U, RC_MEMORY_TYPE_HARDWARE_CONTROLLER, "DSP Memory" },
+    { 0x1FF80000U, 0x1FF81FFFU, 0x1FF80000U, RC_MEMORY_TYPE_READONLY, "Configuration Memory" },
+    { 0x1FF82000U, 0x1FFFFFFFU, 0x1FF82000U, RC_MEMORY_TYPE_SYSTEM_RAM, "Thread Local Storage" }, /* Most of this is actually unused in practice */
+    { 0x20000000U, 0x2FFFFFFFU, 0x20000000U, RC_MEMORY_TYPE_UNUSED, "" },
+    { 0x30000000U, 0x37FFFFFFU, 0x30000000U, RC_MEMORY_TYPE_SYSTEM_RAM, "New Linear Heap" }, /* Newer games use this as the linear heap base instead */
+    { 0x38000000U, 0x3FFFFFFFU, 0x38000000U, RC_MEMORY_TYPE_SYSTEM_RAM, "New Linear Heap (New 3DS Exclusive)" } /* New 3DS exclusive space for the newer linear heap */
+};
+static const rc_memory_regions_t rc_memory_regions_nintendo_3ds = { _rc_memory_regions_nintendo_3ds, 17 };
+
 /* ===== Oric ===== */
 static const rc_memory_region_t _rc_memory_regions_oric[] = {
     /* actual size depends on machine type - up to 64KB */
@@ -1133,6 +1156,9 @@ const rc_memory_regions_t* rc_console_memory_regions(uint32_t console_id)
     case RC_CONSOLE_NINTENDO_DSI:
       return &rc_memory_regions_nintendo_dsi;
 
+    case RC_CONSOLE_NINTENDO_3DS:
+      return &rc_memory_regions_nintendo_3ds;
+
     case RC_CONSOLE_ORIC:
       return &rc_memory_regions_oric;
 

test/rcheevos/test_consoleinfo.c

@@ -163,6 +163,7 @@ void test_consoleinfo(void) {
   TEST_PARAMS2(test_memory, RC_CONSOLE_NEO_GEO_CD, 0x010000);
   TEST_PARAMS2(test_memory, RC_CONSOLE_NINTENDO, 0x010000);
   TEST_PARAMS2(test_memory, RC_CONSOLE_NINTENDO_64, 0x800000);
+  TEST_PARAMS2(test_memory, RC_CONSOLE_NINTENDO_3DS, 0x40000000);
   TEST_PARAMS2(test_memory, RC_CONSOLE_NINTENDO_DS, 0x1004000);
   TEST_PARAMS2(test_memory, RC_CONSOLE_NINTENDO_DSI, 0x1004000);
   TEST_PARAMS2(test_memory, RC_CONSOLE_ORIC, 0x010000);