shithub: sms

Download patch

ref: 4772b9ae836c9aabd775ea1955589784bc6d6c6b
author: Jean-André Santoni <jean.andre.santoni@gmail.com>
date: Sun Jun 30 15:19:03 EDT 2024

initial commit

--- /dev/null
+++ b/Makefile
@@ -1,0 +1,17 @@
+
+TARGET := sms_libretro.so
+SHARED := -shared
+CFLAGS += -O3 -fPIC
+
+OBJ = sms.o z80.o mem.o
+
+.DEFAULT_GOAL := $(TARGET)
+
+%.o: %.c
+	$(CC) -c -o $@ $< $(CFLAGS)
+
+$(TARGET): $(OBJ)
+	$(LD) $(SHARED) -o $@ $^ $(LDFLAGS)
+
+clean:
+	rm -f $(OBJ) $(TARGET)
--- /dev/null
+++ b/dat.h
@@ -1,0 +1,82 @@
+#include <stdint.h>
+
+extern uint32_t curpc, irq;
+
+extern uint8_t reg[32];
+extern uint8_t dma;
+
+extern uint8_t z80bus, z80irq;
+extern uint16_t spc, scurpc;
+
+extern uint16_t ram[32768];
+extern uint8_t *prg;
+extern int nprg;
+extern uint8_t *sram;
+extern uint32_t sramctl, sram0, sram1;
+
+enum {
+	MODE1   = 0x00,
+	MODE2   = 0x01,
+	PANT    = 0x02,
+	PWNT    = 0x03,
+	PBNT    = 0x04,
+	SPRTAB  = 0x05,
+	BGCOL   = 0x07,
+	HORCTR  = 0x0a,
+	MODE3   = 0x0b,
+	MODE4   = 0x0c,
+	HORSCR  = 0x0d,
+	AUTOINC = 0x0f,
+	PLSIZ   = 0x10,
+	WINH    = 0x11,
+	WINV    = 0x12,
+	DMACL   = 0x13,
+	DMACH   = 0x14,
+	DMASRC0 = 0x15,
+	DMASRC1 = 0x16,
+	DMASRC2 = 0x17,
+
+	IE0 = 0x20,
+	IE1 = 0x10,
+	DMAEN = 0x10,
+	SHI = 0x08,
+	
+	WIDE = 0x01,
+	
+	STATDMA = 0x02,
+	STATHBL = 0x04,
+	STATVBL = 0x08,
+	STATFR  = 0x10,
+	STATCOLL= 0x20,
+	STATOVR = 0x40,
+	STATINT = 0x80,
+};
+
+enum {
+	BUSREQ = 1,
+	BUSACK = 2,
+	RESET = 4,
+	
+	INTVBL = 1,
+	INTHOR = 2,
+};
+
+enum {
+	FREQ = 53203400,
+	YMDIV = 7 * 6,
+	CPUDIV = 7,
+	Z80DIV = 15,
+	RATE = 44100,
+	SAMPDIV = FREQ / RATE,
+	SAVEFREQ = FREQ / 4,
+};
+
+enum {
+	SRAM = 0x01,
+	BATTERY = 0x02,
+	ADDRMASK = 0x0c,
+	ADDRBOTH = 0x00,
+	ADDREVEN = 0x08,
+	ADDRODD = 0x0c,
+	SRAMEN = 0x10,
+};
--- /dev/null
+++ b/fns.h
@@ -1,0 +1,11 @@
+#include <stdint.h>
+
+uint16_t memread(uint32_t);
+void memwrite(uint32_t, uint16_t, uint16_t);
+int z80step(void);
+uint8_t z80read(uint16_t);
+void z80write(uint16_t, uint8_t);
+uint8_t z80in(uint8_t);
+void z80out(uint8_t, uint8_t);
+void flush(void);
+void ymwrite(uint8_t, uint8_t, uint8_t);
--- /dev/null
+++ b/libretro.h
@@ -1,0 +1,3144 @@
+/* Copyright (C) 2010-2020 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this libretro API header (libretro.h).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef LIBRETRO_H__
+#define LIBRETRO_H__
+
+#include <stdint.h>
+#include <stddef.h>
+#include <limits.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __cplusplus
+#if defined(_MSC_VER) && _MSC_VER < 1800 && !defined(SN_TARGET_PS3)
+/* Hack applied for MSVC when compiling in C89 mode
+ * as it isn't C99-compliant. */
+#define bool unsigned char
+#define true 1
+#define false 0
+#else
+#include <stdbool.h>
+#endif
+#endif
+
+#ifndef RETRO_CALLCONV
+#  if defined(__GNUC__) && defined(__i386__) && !defined(__x86_64__)
+#    define RETRO_CALLCONV __attribute__((cdecl))
+#  elif defined(_MSC_VER) && defined(_M_X86) && !defined(_M_X64)
+#    define RETRO_CALLCONV __cdecl
+#  else
+#    define RETRO_CALLCONV /* all other platforms only have one calling convention each */
+#  endif
+#endif
+
+#ifndef RETRO_API
+#  if defined(_WIN32) || defined(__CYGWIN__) || defined(__MINGW32__)
+#    ifdef RETRO_IMPORT_SYMBOLS
+#      ifdef __GNUC__
+#        define RETRO_API RETRO_CALLCONV __attribute__((__dllimport__))
+#      else
+#        define RETRO_API RETRO_CALLCONV __declspec(dllimport)
+#      endif
+#    else
+#      ifdef __GNUC__
+#        define RETRO_API RETRO_CALLCONV __attribute__((__dllexport__))
+#      else
+#        define RETRO_API RETRO_CALLCONV __declspec(dllexport)
+#      endif
+#    endif
+#  else
+#      if defined(__GNUC__) && __GNUC__ >= 4
+#        define RETRO_API RETRO_CALLCONV __attribute__((__visibility__("default")))
+#      else
+#        define RETRO_API RETRO_CALLCONV
+#      endif
+#  endif
+#endif
+
+/* Used for checking API/ABI mismatches that can break libretro
+ * implementations.
+ * It is not incremented for compatible changes to the API.
+ */
+#define RETRO_API_VERSION         1
+
+/*
+ * Libretro's fundamental device abstractions.
+ *
+ * Libretro's input system consists of some standardized device types,
+ * such as a joypad (with/without analog), mouse, keyboard, lightgun
+ * and a pointer.
+ *
+ * The functionality of these devices are fixed, and individual cores
+ * map their own concept of a controller to libretro's abstractions.
+ * This makes it possible for frontends to map the abstract types to a
+ * real input device, and not having to worry about binding input
+ * correctly to arbitrary controller layouts.
+ */
+
+#define RETRO_DEVICE_TYPE_SHIFT         8
+#define RETRO_DEVICE_MASK               ((1 << RETRO_DEVICE_TYPE_SHIFT) - 1)
+#define RETRO_DEVICE_SUBCLASS(base, id) (((id + 1) << RETRO_DEVICE_TYPE_SHIFT) | base)
+
+/* Input disabled. */
+#define RETRO_DEVICE_NONE         0
+
+/* The JOYPAD is called RetroPad. It is essentially a Super Nintendo
+ * controller, but with additional L2/R2/L3/R3 buttons, similar to a
+ * PS1 DualShock. */
+#define RETRO_DEVICE_JOYPAD       1
+
+/* The mouse is a simple mouse, similar to Super Nintendo's mouse.
+ * X and Y coordinates are reported relatively to last poll (poll callback).
+ * It is up to the libretro implementation to keep track of where the mouse
+ * pointer is supposed to be on the screen.
+ * The frontend must make sure not to interfere with its own hardware
+ * mouse pointer.
+ */
+#define RETRO_DEVICE_MOUSE        2
+
+/* KEYBOARD device lets one poll for raw key pressed.
+ * It is poll based, so input callback will return with the current
+ * pressed state.
+ * For event/text based keyboard input, see
+ * RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK.
+ */
+#define RETRO_DEVICE_KEYBOARD     3
+
+/* LIGHTGUN device is similar to Guncon-2 for PlayStation 2.
+ * It reports X/Y coordinates in screen space (similar to the pointer)
+ * in the range [-0x8000, 0x7fff] in both axes, with zero being center and
+ * -0x8000 being out of bounds.
+ * As well as reporting on/off screen state. It features a trigger,
+ * start/select buttons, auxiliary action buttons and a
+ * directional pad. A forced off-screen shot can be requested for
+ * auto-reloading function in some games.
+ */
+#define RETRO_DEVICE_LIGHTGUN     4
+
+/* The ANALOG device is an extension to JOYPAD (RetroPad).
+ * Similar to DualShock2 it adds two analog sticks and all buttons can
+ * be analog. This is treated as a separate device type as it returns
+ * axis values in the full analog range of [-0x7fff, 0x7fff],
+ * although some devices may return -0x8000.
+ * Positive X axis is right. Positive Y axis is down.
+ * Buttons are returned in the range [0, 0x7fff].
+ * Only use ANALOG type when polling for analog values.
+ */
+#define RETRO_DEVICE_ANALOG       5
+
+/* Abstracts the concept of a pointing mechanism, e.g. touch.
+ * This allows libretro to query in absolute coordinates where on the
+ * screen a mouse (or something similar) is being placed.
+ * For a touch centric device, coordinates reported are the coordinates
+ * of the press.
+ *
+ * Coordinates in X and Y are reported as:
+ * [-0x7fff, 0x7fff]: -0x7fff corresponds to the far left/top of the screen,
+ * and 0x7fff corresponds to the far right/bottom of the screen.
+ * The "screen" is here defined as area that is passed to the frontend and
+ * later displayed on the monitor.
+ *
+ * The frontend is free to scale/resize this screen as it sees fit, however,
+ * (X, Y) = (-0x7fff, -0x7fff) will correspond to the top-left pixel of the
+ * game image, etc.
+ *
+ * To check if the pointer coordinates are valid (e.g. a touch display
+ * actually being touched), PRESSED returns 1 or 0.
+ *
+ * If using a mouse on a desktop, PRESSED will usually correspond to the
+ * left mouse button, but this is a frontend decision.
+ * PRESSED will only return 1 if the pointer is inside the game screen.
+ *
+ * For multi-touch, the index variable can be used to successively query
+ * more presses.
+ * If index = 0 returns true for _PRESSED, coordinates can be extracted
+ * with _X, _Y for index = 0. One can then query _PRESSED, _X, _Y with
+ * index = 1, and so on.
+ * Eventually _PRESSED will return false for an index. No further presses
+ * are registered at this point. */
+#define RETRO_DEVICE_POINTER      6
+
+/* Buttons for the RetroPad (JOYPAD).
+ * The placement of these is equivalent to placements on the
+ * Super Nintendo controller.
+ * L2/R2/L3/R3 buttons correspond to the PS1 DualShock.
+ * Also used as id values for RETRO_DEVICE_INDEX_ANALOG_BUTTON */
+#define RETRO_DEVICE_ID_JOYPAD_B        0
+#define RETRO_DEVICE_ID_JOYPAD_Y        1
+#define RETRO_DEVICE_ID_JOYPAD_SELECT   2
+#define RETRO_DEVICE_ID_JOYPAD_START    3
+#define RETRO_DEVICE_ID_JOYPAD_UP       4
+#define RETRO_DEVICE_ID_JOYPAD_DOWN     5
+#define RETRO_DEVICE_ID_JOYPAD_LEFT     6
+#define RETRO_DEVICE_ID_JOYPAD_RIGHT    7
+#define RETRO_DEVICE_ID_JOYPAD_A        8
+#define RETRO_DEVICE_ID_JOYPAD_X        9
+#define RETRO_DEVICE_ID_JOYPAD_L       10
+#define RETRO_DEVICE_ID_JOYPAD_R       11
+#define RETRO_DEVICE_ID_JOYPAD_L2      12
+#define RETRO_DEVICE_ID_JOYPAD_R2      13
+#define RETRO_DEVICE_ID_JOYPAD_L3      14
+#define RETRO_DEVICE_ID_JOYPAD_R3      15
+
+#define RETRO_DEVICE_ID_JOYPAD_MASK    256
+
+/* Index / Id values for ANALOG device. */
+#define RETRO_DEVICE_INDEX_ANALOG_LEFT       0
+#define RETRO_DEVICE_INDEX_ANALOG_RIGHT      1
+#define RETRO_DEVICE_INDEX_ANALOG_BUTTON     2
+#define RETRO_DEVICE_ID_ANALOG_X             0
+#define RETRO_DEVICE_ID_ANALOG_Y             1
+
+/* Id values for MOUSE. */
+#define RETRO_DEVICE_ID_MOUSE_X                0
+#define RETRO_DEVICE_ID_MOUSE_Y                1
+#define RETRO_DEVICE_ID_MOUSE_LEFT             2
+#define RETRO_DEVICE_ID_MOUSE_RIGHT            3
+#define RETRO_DEVICE_ID_MOUSE_WHEELUP          4
+#define RETRO_DEVICE_ID_MOUSE_WHEELDOWN        5
+#define RETRO_DEVICE_ID_MOUSE_MIDDLE           6
+#define RETRO_DEVICE_ID_MOUSE_HORIZ_WHEELUP    7
+#define RETRO_DEVICE_ID_MOUSE_HORIZ_WHEELDOWN  8
+#define RETRO_DEVICE_ID_MOUSE_BUTTON_4         9
+#define RETRO_DEVICE_ID_MOUSE_BUTTON_5         10
+
+/* Id values for LIGHTGUN. */
+#define RETRO_DEVICE_ID_LIGHTGUN_SCREEN_X        13 /*Absolute Position*/
+#define RETRO_DEVICE_ID_LIGHTGUN_SCREEN_Y        14 /*Absolute*/
+#define RETRO_DEVICE_ID_LIGHTGUN_IS_OFFSCREEN    15 /*Status Check*/
+#define RETRO_DEVICE_ID_LIGHTGUN_TRIGGER          2
+#define RETRO_DEVICE_ID_LIGHTGUN_RELOAD          16 /*Forced off-screen shot*/
+#define RETRO_DEVICE_ID_LIGHTGUN_AUX_A            3
+#define RETRO_DEVICE_ID_LIGHTGUN_AUX_B            4
+#define RETRO_DEVICE_ID_LIGHTGUN_START            6
+#define RETRO_DEVICE_ID_LIGHTGUN_SELECT           7
+#define RETRO_DEVICE_ID_LIGHTGUN_AUX_C            8
+#define RETRO_DEVICE_ID_LIGHTGUN_DPAD_UP          9
+#define RETRO_DEVICE_ID_LIGHTGUN_DPAD_DOWN       10
+#define RETRO_DEVICE_ID_LIGHTGUN_DPAD_LEFT       11
+#define RETRO_DEVICE_ID_LIGHTGUN_DPAD_RIGHT      12
+/* deprecated */
+#define RETRO_DEVICE_ID_LIGHTGUN_X                0 /*Relative Position*/
+#define RETRO_DEVICE_ID_LIGHTGUN_Y                1 /*Relative*/
+#define RETRO_DEVICE_ID_LIGHTGUN_CURSOR           3 /*Use Aux:A*/
+#define RETRO_DEVICE_ID_LIGHTGUN_TURBO            4 /*Use Aux:B*/
+#define RETRO_DEVICE_ID_LIGHTGUN_PAUSE            5 /*Use Start*/
+
+/* Id values for POINTER. */
+#define RETRO_DEVICE_ID_POINTER_X         0
+#define RETRO_DEVICE_ID_POINTER_Y         1
+#define RETRO_DEVICE_ID_POINTER_PRESSED   2
+#define RETRO_DEVICE_ID_POINTER_COUNT     3
+
+/* Returned from retro_get_region(). */
+#define RETRO_REGION_NTSC  0
+#define RETRO_REGION_PAL   1
+
+/* Id values for LANGUAGE */
+enum retro_language
+{
+   RETRO_LANGUAGE_ENGLISH             = 0,
+   RETRO_LANGUAGE_JAPANESE            = 1,
+   RETRO_LANGUAGE_FRENCH              = 2,
+   RETRO_LANGUAGE_SPANISH             = 3,
+   RETRO_LANGUAGE_GERMAN              = 4,
+   RETRO_LANGUAGE_ITALIAN             = 5,
+   RETRO_LANGUAGE_DUTCH               = 6,
+   RETRO_LANGUAGE_PORTUGUESE_BRAZIL   = 7,
+   RETRO_LANGUAGE_PORTUGUESE_PORTUGAL = 8,
+   RETRO_LANGUAGE_RUSSIAN             = 9,
+   RETRO_LANGUAGE_KOREAN              = 10,
+   RETRO_LANGUAGE_CHINESE_TRADITIONAL = 11,
+   RETRO_LANGUAGE_CHINESE_SIMPLIFIED  = 12,
+   RETRO_LANGUAGE_ESPERANTO           = 13,
+   RETRO_LANGUAGE_POLISH              = 14,
+   RETRO_LANGUAGE_VIETNAMESE          = 15,
+   RETRO_LANGUAGE_ARABIC              = 16,
+   RETRO_LANGUAGE_GREEK               = 17,
+   RETRO_LANGUAGE_TURKISH             = 18,
+   RETRO_LANGUAGE_SLOVAK              = 19,
+   RETRO_LANGUAGE_PERSIAN             = 20,
+   RETRO_LANGUAGE_HEBREW              = 21,
+   RETRO_LANGUAGE_ASTURIAN            = 22,
+   RETRO_LANGUAGE_FINNISH             = 23,
+   RETRO_LANGUAGE_LAST,
+
+   /* Ensure sizeof(enum) == sizeof(int) */
+   RETRO_LANGUAGE_DUMMY          = INT_MAX
+};
+
+/* Passed to retro_get_memory_data/size().
+ * If the memory type doesn't apply to the
+ * implementation NULL/0 can be returned.
+ */
+#define RETRO_MEMORY_MASK        0xff
+
+/* Regular save RAM. This RAM is usually found on a game cartridge,
+ * backed up by a battery.
+ * If save game data is too complex for a single memory buffer,
+ * the SAVE_DIRECTORY (preferably) or SYSTEM_DIRECTORY environment
+ * callback can be used. */
+#define RETRO_MEMORY_SAVE_RAM    0
+
+/* Some games have a built-in clock to keep track of time.
+ * This memory is usually just a couple of bytes to keep track of time.
+ */
+#define RETRO_MEMORY_RTC         1
+
+/* System ram lets a frontend peek into a game systems main RAM. */
+#define RETRO_MEMORY_SYSTEM_RAM  2
+
+/* Video ram lets a frontend peek into a game systems video RAM (VRAM). */
+#define RETRO_MEMORY_VIDEO_RAM   3
+
+/* Keysyms used for ID in input state callback when polling RETRO_KEYBOARD. */
+enum retro_key
+{
+   RETROK_UNKNOWN        = 0,
+   RETROK_FIRST          = 0,
+   RETROK_BACKSPACE      = 8,
+   RETROK_TAB            = 9,
+   RETROK_CLEAR          = 12,
+   RETROK_RETURN         = 13,
+   RETROK_PAUSE          = 19,
+   RETROK_ESCAPE         = 27,
+   RETROK_SPACE          = 32,
+   RETROK_EXCLAIM        = 33,
+   RETROK_QUOTEDBL       = 34,
+   RETROK_HASH           = 35,
+   RETROK_DOLLAR         = 36,
+   RETROK_AMPERSAND      = 38,
+   RETROK_QUOTE          = 39,
+   RETROK_LEFTPAREN      = 40,
+   RETROK_RIGHTPAREN     = 41,
+   RETROK_ASTERISK       = 42,
+   RETROK_PLUS           = 43,
+   RETROK_COMMA          = 44,
+   RETROK_MINUS          = 45,
+   RETROK_PERIOD         = 46,
+   RETROK_SLASH          = 47,
+   RETROK_0              = 48,
+   RETROK_1              = 49,
+   RETROK_2              = 50,
+   RETROK_3              = 51,
+   RETROK_4              = 52,
+   RETROK_5              = 53,
+   RETROK_6              = 54,
+   RETROK_7              = 55,
+   RETROK_8              = 56,
+   RETROK_9              = 57,
+   RETROK_COLON          = 58,
+   RETROK_SEMICOLON      = 59,
+   RETROK_LESS           = 60,
+   RETROK_EQUALS         = 61,
+   RETROK_GREATER        = 62,
+   RETROK_QUESTION       = 63,
+   RETROK_AT             = 64,
+   RETROK_LEFTBRACKET    = 91,
+   RETROK_BACKSLASH      = 92,
+   RETROK_RIGHTBRACKET   = 93,
+   RETROK_CARET          = 94,
+   RETROK_UNDERSCORE     = 95,
+   RETROK_BACKQUOTE      = 96,
+   RETROK_a              = 97,
+   RETROK_b              = 98,
+   RETROK_c              = 99,
+   RETROK_d              = 100,
+   RETROK_e              = 101,
+   RETROK_f              = 102,
+   RETROK_g              = 103,
+   RETROK_h              = 104,
+   RETROK_i              = 105,
+   RETROK_j              = 106,
+   RETROK_k              = 107,
+   RETROK_l              = 108,
+   RETROK_m              = 109,
+   RETROK_n              = 110,
+   RETROK_o              = 111,
+   RETROK_p              = 112,
+   RETROK_q              = 113,
+   RETROK_r              = 114,
+   RETROK_s              = 115,
+   RETROK_t              = 116,
+   RETROK_u              = 117,
+   RETROK_v              = 118,
+   RETROK_w              = 119,
+   RETROK_x              = 120,
+   RETROK_y              = 121,
+   RETROK_z              = 122,
+   RETROK_LEFTBRACE      = 123,
+   RETROK_BAR            = 124,
+   RETROK_RIGHTBRACE     = 125,
+   RETROK_TILDE          = 126,
+   RETROK_DELETE         = 127,
+
+   RETROK_KP0            = 256,
+   RETROK_KP1            = 257,
+   RETROK_KP2            = 258,
+   RETROK_KP3            = 259,
+   RETROK_KP4            = 260,
+   RETROK_KP5            = 261,
+   RETROK_KP6            = 262,
+   RETROK_KP7            = 263,
+   RETROK_KP8            = 264,
+   RETROK_KP9            = 265,
+   RETROK_KP_PERIOD      = 266,
+   RETROK_KP_DIVIDE      = 267,
+   RETROK_KP_MULTIPLY    = 268,
+   RETROK_KP_MINUS       = 269,
+   RETROK_KP_PLUS        = 270,
+   RETROK_KP_ENTER       = 271,
+   RETROK_KP_EQUALS      = 272,
+
+   RETROK_UP             = 273,
+   RETROK_DOWN           = 274,
+   RETROK_RIGHT          = 275,
+   RETROK_LEFT           = 276,
+   RETROK_INSERT         = 277,
+   RETROK_HOME           = 278,
+   RETROK_END            = 279,
+   RETROK_PAGEUP         = 280,
+   RETROK_PAGEDOWN       = 281,
+
+   RETROK_F1             = 282,
+   RETROK_F2             = 283,
+   RETROK_F3             = 284,
+   RETROK_F4             = 285,
+   RETROK_F5             = 286,
+   RETROK_F6             = 287,
+   RETROK_F7             = 288,
+   RETROK_F8             = 289,
+   RETROK_F9             = 290,
+   RETROK_F10            = 291,
+   RETROK_F11            = 292,
+   RETROK_F12            = 293,
+   RETROK_F13            = 294,
+   RETROK_F14            = 295,
+   RETROK_F15            = 296,
+
+   RETROK_NUMLOCK        = 300,
+   RETROK_CAPSLOCK       = 301,
+   RETROK_SCROLLOCK      = 302,
+   RETROK_RSHIFT         = 303,
+   RETROK_LSHIFT         = 304,
+   RETROK_RCTRL          = 305,
+   RETROK_LCTRL          = 306,
+   RETROK_RALT           = 307,
+   RETROK_LALT           = 308,
+   RETROK_RMETA          = 309,
+   RETROK_LMETA          = 310,
+   RETROK_LSUPER         = 311,
+   RETROK_RSUPER         = 312,
+   RETROK_MODE           = 313,
+   RETROK_COMPOSE        = 314,
+
+   RETROK_HELP           = 315,
+   RETROK_PRINT          = 316,
+   RETROK_SYSREQ         = 317,
+   RETROK_BREAK          = 318,
+   RETROK_MENU           = 319,
+   RETROK_POWER          = 320,
+   RETROK_EURO           = 321,
+   RETROK_UNDO           = 322,
+   RETROK_OEM_102        = 323,
+
+   RETROK_LAST,
+
+   RETROK_DUMMY          = INT_MAX /* Ensure sizeof(enum) == sizeof(int) */
+};
+
+enum retro_mod
+{
+   RETROKMOD_NONE       = 0x0000,
+
+   RETROKMOD_SHIFT      = 0x01,
+   RETROKMOD_CTRL       = 0x02,
+   RETROKMOD_ALT        = 0x04,
+   RETROKMOD_META       = 0x08,
+
+   RETROKMOD_NUMLOCK    = 0x10,
+   RETROKMOD_CAPSLOCK   = 0x20,
+   RETROKMOD_SCROLLOCK  = 0x40,
+
+   RETROKMOD_DUMMY = INT_MAX /* Ensure sizeof(enum) == sizeof(int) */
+};
+
+/* If set, this call is not part of the public libretro API yet. It can
+ * change or be removed at any time. */
+#define RETRO_ENVIRONMENT_EXPERIMENTAL 0x10000
+/* Environment callback to be used internally in frontend. */
+#define RETRO_ENVIRONMENT_PRIVATE 0x20000
+
+/* Environment commands. */
+#define RETRO_ENVIRONMENT_SET_ROTATION  1  /* const unsigned * --
+                                            * Sets screen rotation of graphics.
+                                            * Valid values are 0, 1, 2, 3, which rotates screen by 0, 90, 180,
+                                            * 270 degrees counter-clockwise respectively.
+                                            */
+#define RETRO_ENVIRONMENT_GET_OVERSCAN  2  /* bool * --
+                                            * NOTE: As of 2019 this callback is considered deprecated in favor of
+                                            * using core options to manage overscan in a more nuanced, core-specific way.
+                                            *
+                                            * Boolean value whether or not the implementation should use overscan,
+                                            * or crop away overscan.
+                                            */
+#define RETRO_ENVIRONMENT_GET_CAN_DUPE  3  /* bool * --
+                                            * Boolean value whether or not frontend supports frame duping,
+                                            * passing NULL to video frame callback.
+                                            */
+
+                                           /* Environ 4, 5 are no longer supported (GET_VARIABLE / SET_VARIABLES),
+                                            * and reserved to avoid possible ABI clash.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_MESSAGE   6  /* const struct retro_message * --
+                                            * Sets a message to be displayed in implementation-specific manner
+                                            * for a certain amount of 'frames'.
+                                            * Should not be used for trivial messages, which should simply be
+                                            * logged via RETRO_ENVIRONMENT_GET_LOG_INTERFACE (or as a
+                                            * fallback, stderr).
+                                            */
+#define RETRO_ENVIRONMENT_SHUTDOWN      7  /* N/A (NULL) --
+                                            * Requests the frontend to shutdown.
+                                            * Should only be used if game has a specific
+                                            * way to shutdown the game from a menu item or similar.
+                                            */
+#define RETRO_ENVIRONMENT_SET_PERFORMANCE_LEVEL 8
+                                           /* const unsigned * --
+                                            * Gives a hint to the frontend how demanding this implementation
+                                            * is on a system. E.g. reporting a level of 2 means
+                                            * this implementation should run decently on all frontends
+                                            * of level 2 and up.
+                                            *
+                                            * It can be used by the frontend to potentially warn
+                                            * about too demanding implementations.
+                                            *
+                                            * The levels are "floating".
+                                            *
+                                            * This function can be called on a per-game basis,
+                                            * as certain games an implementation can play might be
+                                            * particularly demanding.
+                                            * If called, it should be called in retro_load_game().
+                                            */
+#define RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY 9
+                                           /* const char ** --
+                                            * Returns the "system" directory of the frontend.
+                                            * This directory can be used to store system specific
+                                            * content such as BIOSes, configuration data, etc.
+                                            * The returned value can be NULL.
+                                            * If so, no such directory is defined,
+                                            * and it's up to the implementation to find a suitable directory.
+                                            *
+                                            * NOTE: Some cores used this folder also for "save" data such as
+                                            * memory cards, etc, for lack of a better place to put it.
+                                            * This is now discouraged, and if possible, cores should try to
+                                            * use the new GET_SAVE_DIRECTORY.
+                                            */
+#define RETRO_ENVIRONMENT_SET_PIXEL_FORMAT 10
+                                           /* const enum retro_pixel_format * --
+                                            * Sets the internal pixel format used by the implementation.
+                                            * The default pixel format is RETRO_PIXEL_FORMAT_0RGB1555.
+                                            * This pixel format however, is deprecated (see enum retro_pixel_format).
+                                            * If the call returns false, the frontend does not support this pixel
+                                            * format.
+                                            *
+                                            * This function should be called inside retro_load_game() or
+                                            * retro_get_system_av_info().
+                                            */
+#define RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS 11
+                                           /* const struct retro_input_descriptor * --
+                                            * Sets an array of retro_input_descriptors.
+                                            * It is up to the frontend to present this in a usable way.
+                                            * The array is terminated by retro_input_descriptor::description
+                                            * being set to NULL.
+                                            * This function can be called at any time, but it is recommended
+                                            * to call it as early as possible.
+                                            */
+#define RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK 12
+                                           /* const struct retro_keyboard_callback * --
+                                            * Sets a callback function used to notify core about keyboard events.
+                                            */
+#define RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE 13
+                                           /* const struct retro_disk_control_callback * --
+                                            * Sets an interface which frontend can use to eject and insert
+                                            * disk images.
+                                            * This is used for games which consist of multiple images and
+                                            * must be manually swapped out by the user (e.g. PSX).
+                                            */
+#define RETRO_ENVIRONMENT_SET_HW_RENDER 14
+                                           /* struct retro_hw_render_callback * --
+                                            * Sets an interface to let a libretro core render with
+                                            * hardware acceleration.
+                                            * Should be called in retro_load_game().
+                                            * If successful, libretro cores will be able to render to a
+                                            * frontend-provided framebuffer.
+                                            * The size of this framebuffer will be at least as large as
+                                            * max_width/max_height provided in get_av_info().
+                                            * If HW rendering is used, pass only RETRO_HW_FRAME_BUFFER_VALID or
+                                            * NULL to retro_video_refresh_t.
+                                            */
+#define RETRO_ENVIRONMENT_GET_VARIABLE 15
+                                           /* struct retro_variable * --
+                                            * Interface to acquire user-defined information from environment
+                                            * that cannot feasibly be supported in a multi-system way.
+                                            * 'key' should be set to a key which has already been set by
+                                            * SET_VARIABLES.
+                                            * 'data' will be set to a value or NULL.
+                                            */
+#define RETRO_ENVIRONMENT_SET_VARIABLES 16
+                                           /* const struct retro_variable * --
+                                            * Allows an implementation to signal the environment
+                                            * which variables it might want to check for later using
+                                            * GET_VARIABLE.
+                                            * This allows the frontend to present these variables to
+                                            * a user dynamically.
+                                            * This should be called the first time as early as
+                                            * possible (ideally in retro_set_environment).
+                                            * Afterward it may be called again for the core to communicate
+                                            * updated options to the frontend, but the number of core
+                                            * options must not change from the number in the initial call.
+                                            *
+                                            * 'data' points to an array of retro_variable structs
+                                            * terminated by a { NULL, NULL } element.
+                                            * retro_variable::key should be namespaced to not collide
+                                            * with other implementations' keys. E.g. A core called
+                                            * 'foo' should use keys named as 'foo_option'.
+                                            * retro_variable::value should contain a human readable
+                                            * description of the key as well as a '|' delimited list
+                                            * of expected values.
+                                            *
+                                            * The number of possible options should be very limited,
+                                            * i.e. it should be feasible to cycle through options
+                                            * without a keyboard.
+                                            *
+                                            * First entry should be treated as a default.
+                                            *
+                                            * Example entry:
+                                            * { "foo_option", "Speed hack coprocessor X; false|true" }
+                                            *
+                                            * Text before first ';' is description. This ';' must be
+                                            * followed by a space, and followed by a list of possible
+                                            * values split up with '|'.
+                                            *
+                                            * Only strings are operated on. The possible values will
+                                            * generally be displayed and stored as-is by the frontend.
+                                            */
+#define RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE 17
+                                           /* bool * --
+                                            * Result is set to true if some variables are updated by
+                                            * frontend since last call to RETRO_ENVIRONMENT_GET_VARIABLE.
+                                            * Variables should be queried with GET_VARIABLE.
+                                            */
+#define RETRO_ENVIRONMENT_SET_SUPPORT_NO_GAME 18
+                                           /* const bool * --
+                                            * If true, the libretro implementation supports calls to
+                                            * retro_load_game() with NULL as argument.
+                                            * Used by cores which can run without particular game data.
+                                            * This should be called within retro_set_environment() only.
+                                            */
+#define RETRO_ENVIRONMENT_GET_LIBRETRO_PATH 19
+                                           /* const char ** --
+                                            * Retrieves the absolute path from where this libretro
+                                            * implementation was loaded.
+                                            * NULL is returned if the libretro was loaded statically
+                                            * (i.e. linked statically to frontend), or if the path cannot be
+                                            * determined.
+                                            * Mostly useful in cooperation with SET_SUPPORT_NO_GAME as assets can
+                                            * be loaded without ugly hacks.
+                                            */
+
+                                           /* Environment 20 was an obsolete version of SET_AUDIO_CALLBACK.
+                                            * It was not used by any known core at the time,
+                                            * and was removed from the API. */
+#define RETRO_ENVIRONMENT_SET_FRAME_TIME_CALLBACK 21
+                                           /* const struct retro_frame_time_callback * --
+                                            * Lets the core know how much time has passed since last
+                                            * invocation of retro_run().
+                                            * The frontend can tamper with the timing to fake fast-forward,
+                                            * slow-motion, frame stepping, etc.
+                                            * In this case the delta time will use the reference value
+                                            * in frame_time_callback..
+                                            */
+#define RETRO_ENVIRONMENT_SET_AUDIO_CALLBACK 22
+                                           /* const struct retro_audio_callback * --
+                                            * Sets an interface which is used to notify a libretro core about audio
+                                            * being available for writing.
+                                            * The callback can be called from any thread, so a core using this must
+                                            * have a thread safe audio implementation.
+                                            * It is intended for games where audio and video are completely
+                                            * asynchronous and audio can be generated on the fly.
+                                            * This interface is not recommended for use with emulators which have
+                                            * highly synchronous audio.
+                                            *
+                                            * The callback only notifies about writability; the libretro core still
+                                            * has to call the normal audio callbacks
+                                            * to write audio. The audio callbacks must be called from within the
+                                            * notification callback.
+                                            * The amount of audio data to write is up to the implementation.
+                                            * Generally, the audio callback will be called continously in a loop.
+                                            *
+                                            * Due to thread safety guarantees and lack of sync between audio and
+                                            * video, a frontend  can selectively disallow this interface based on
+                                            * internal configuration. A core using this interface must also
+                                            * implement the "normal" audio interface.
+                                            *
+                                            * A libretro core using SET_AUDIO_CALLBACK should also make use of
+                                            * SET_FRAME_TIME_CALLBACK.
+                                            */
+#define RETRO_ENVIRONMENT_GET_RUMBLE_INTERFACE 23
+                                           /* struct retro_rumble_interface * --
+                                            * Gets an interface which is used by a libretro core to set
+                                            * state of rumble motors in controllers.
+                                            * A strong and weak motor is supported, and they can be
+                                            * controlled indepedently.
+                                            * Should be called from either retro_init() or retro_load_game().
+                                            * Should not be called from retro_set_environment().
+                                            * Returns false if rumble functionality is unavailable.
+                                            */
+#define RETRO_ENVIRONMENT_GET_INPUT_DEVICE_CAPABILITIES 24
+                                           /* uint64_t * --
+                                            * Gets a bitmask telling which device type are expected to be
+                                            * handled properly in a call to retro_input_state_t.
+                                            * Devices which are not handled or recognized always return
+                                            * 0 in retro_input_state_t.
+                                            * Example bitmask: caps = (1 << RETRO_DEVICE_JOYPAD) | (1 << RETRO_DEVICE_ANALOG).
+                                            * Should only be called in retro_run().
+                                            */
+#define RETRO_ENVIRONMENT_GET_SENSOR_INTERFACE (25 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* struct retro_sensor_interface * --
+                                            * Gets access to the sensor interface.
+                                            * The purpose of this interface is to allow
+                                            * setting state related to sensors such as polling rate,
+                                            * enabling/disable it entirely, etc.
+                                            * Reading sensor state is done via the normal
+                                            * input_state_callback API.
+                                            */
+#define RETRO_ENVIRONMENT_GET_CAMERA_INTERFACE (26 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* struct retro_camera_callback * --
+                                            * Gets an interface to a video camera driver.
+                                            * A libretro core can use this interface to get access to a
+                                            * video camera.
+                                            * New video frames are delivered in a callback in same
+                                            * thread as retro_run().
+                                            *
+                                            * GET_CAMERA_INTERFACE should be called in retro_load_game().
+                                            *
+                                            * Depending on the camera implementation used, camera frames
+                                            * will be delivered as a raw framebuffer,
+                                            * or as an OpenGL texture directly.
+                                            *
+                                            * The core has to tell the frontend here which types of
+                                            * buffers can be handled properly.
+                                            * An OpenGL texture can only be handled when using a
+                                            * libretro GL core (SET_HW_RENDER).
+                                            * It is recommended to use a libretro GL core when
+                                            * using camera interface.
+                                            *
+                                            * The camera is not started automatically. The retrieved start/stop
+                                            * functions must be used to explicitly
+                                            * start and stop the camera driver.
+                                            */
+#define RETRO_ENVIRONMENT_GET_LOG_INTERFACE 27
+                                           /* struct retro_log_callback * --
+                                            * Gets an interface for logging. This is useful for
+                                            * logging in a cross-platform way
+                                            * as certain platforms cannot use stderr for logging.
+                                            * It also allows the frontend to
+                                            * show logging information in a more suitable way.
+                                            * If this interface is not used, libretro cores should
+                                            * log to stderr as desired.
+                                            */
+#define RETRO_ENVIRONMENT_GET_PERF_INTERFACE 28
+                                           /* struct retro_perf_callback * --
+                                            * Gets an interface for performance counters. This is useful
+                                            * for performance logging in a cross-platform way and for detecting
+                                            * architecture-specific features, such as SIMD support.
+                                            */
+#define RETRO_ENVIRONMENT_GET_LOCATION_INTERFACE 29
+                                           /* struct retro_location_callback * --
+                                            * Gets access to the location interface.
+                                            * The purpose of this interface is to be able to retrieve
+                                            * location-based information from the host device,
+                                            * such as current latitude / longitude.
+                                            */
+#define RETRO_ENVIRONMENT_GET_CONTENT_DIRECTORY 30 /* Old name, kept for compatibility. */
+#define RETRO_ENVIRONMENT_GET_CORE_ASSETS_DIRECTORY 30
+                                           /* const char ** --
+                                            * Returns the "core assets" directory of the frontend.
+                                            * This directory can be used to store specific assets that the
+                                            * core relies upon, such as art assets,
+                                            * input data, etc etc.
+                                            * The returned value can be NULL.
+                                            * If so, no such directory is defined,
+                                            * and it's up to the implementation to find a suitable directory.
+                                            */
+#define RETRO_ENVIRONMENT_GET_SAVE_DIRECTORY 31
+                                           /* const char ** --
+                                            * Returns the "save" directory of the frontend, unless there is no
+                                            * save directory available. The save directory should be used to
+                                            * store SRAM, memory cards, high scores, etc, if the libretro core
+                                            * cannot use the regular memory interface (retro_get_memory_data()).
+                                            *
+                                            * If the frontend cannot designate a save directory, it will return
+                                            * NULL to indicate that the core should attempt to operate without a
+                                            * save directory set.
+                                            *
+                                            * NOTE: early libretro cores used the system directory for save
+                                            * files. Cores that need to be backwards-compatible can still check
+                                            * GET_SYSTEM_DIRECTORY.
+                                            */
+#define RETRO_ENVIRONMENT_SET_SYSTEM_AV_INFO 32
+                                           /* const struct retro_system_av_info * --
+                                            * Sets a new av_info structure. This can only be called from
+                                            * within retro_run().
+                                            * This should *only* be used if the core is completely altering the
+                                            * internal resolutions, aspect ratios, timings, sampling rate, etc.
+                                            * Calling this can require a full reinitialization of video/audio
+                                            * drivers in the frontend,
+                                            *
+                                            * so it is important to call it very sparingly, and usually only with
+                                            * the users explicit consent.
+                                            * An eventual driver reinitialize will happen so that video and
+                                            * audio callbacks
+                                            * happening after this call within the same retro_run() call will
+                                            * target the newly initialized driver.
+                                            *
+                                            * This callback makes it possible to support configurable resolutions
+                                            * in games, which can be useful to
+                                            * avoid setting the "worst case" in max_width/max_height.
+                                            *
+                                            * ***HIGHLY RECOMMENDED*** Do not call this callback every time
+                                            * resolution changes in an emulator core if it's
+                                            * expected to be a temporary change, for the reasons of possible
+                                            * driver reinitialization.
+                                            * This call is not a free pass for not trying to provide
+                                            * correct values in retro_get_system_av_info(). If you need to change
+                                            * things like aspect ratio or nominal width/height,
+                                            * use RETRO_ENVIRONMENT_SET_GEOMETRY, which is a softer variant
+                                            * of SET_SYSTEM_AV_INFO.
+                                            *
+                                            * If this returns false, the frontend does not acknowledge a
+                                            * changed av_info struct.
+                                            */
+#define RETRO_ENVIRONMENT_SET_PROC_ADDRESS_CALLBACK 33
+                                           /* const struct retro_get_proc_address_interface * --
+                                            * Allows a libretro core to announce support for the
+                                            * get_proc_address() interface.
+                                            * This interface allows for a standard way to extend libretro where
+                                            * use of environment calls are too indirect,
+                                            * e.g. for cases where the frontend wants to call directly into the core.
+                                            *
+                                            * If a core wants to expose this interface, SET_PROC_ADDRESS_CALLBACK
+                                            * **MUST** be called from within retro_set_environment().
+                                            */
+#define RETRO_ENVIRONMENT_SET_SUBSYSTEM_INFO 34
+                                           /* const struct retro_subsystem_info * --
+                                            * This environment call introduces the concept of libretro "subsystems".
+                                            * A subsystem is a variant of a libretro core which supports
+                                            * different kinds of games.
+                                            * The purpose of this is to support e.g. emulators which might
+                                            * have special needs, e.g. Super Nintendo's Super GameBoy, Sufami Turbo.
+                                            * It can also be used to pick among subsystems in an explicit way
+                                            * if the libretro implementation is a multi-system emulator itself.
+                                            *
+                                            * Loading a game via a subsystem is done with retro_load_game_special(),
+                                            * and this environment call allows a libretro core to expose which
+                                            * subsystems are supported for use with retro_load_game_special().
+                                            * A core passes an array of retro_game_special_info which is terminated
+                                            * with a zeroed out retro_game_special_info struct.
+                                            *
+                                            * If a core wants to use this functionality, SET_SUBSYSTEM_INFO
+                                            * **MUST** be called from within retro_set_environment().
+                                            */
+#define RETRO_ENVIRONMENT_SET_CONTROLLER_INFO 35
+                                           /* const struct retro_controller_info * --
+                                            * This environment call lets a libretro core tell the frontend
+                                            * which controller subclasses are recognized in calls to
+                                            * retro_set_controller_port_device().
+                                            *
+                                            * Some emulators such as Super Nintendo support multiple lightgun
+                                            * types which must be specifically selected from. It is therefore
+                                            * sometimes necessary for a frontend to be able to tell the core
+                                            * about a special kind of input device which is not specifcally
+                                            * provided by the Libretro API.
+                                            *
+                                            * In order for a frontend to understand the workings of those devices,
+                                            * they must be defined as a specialized subclass of the generic device
+                                            * types already defined in the libretro API.
+                                            *
+                                            * The core must pass an array of const struct retro_controller_info which
+                                            * is terminated with a blanked out struct. Each element of the
+                                            * retro_controller_info struct corresponds to the ascending port index
+                                            * that is passed to retro_set_controller_port_device() when that function
+                                            * is called to indicate to the core that the frontend has changed the
+                                            * active device subclass. SEE ALSO: retro_set_controller_port_device()
+                                            *
+                                            * The ascending input port indexes provided by the core in the struct
+                                            * are generally presented by frontends as ascending User # or Player #,
+                                            * such as Player 1, Player 2, Player 3, etc. Which device subclasses are
+                                            * supported can vary per input port.
+                                            *
+                                            * The first inner element of each entry in the retro_controller_info array
+                                            * is a retro_controller_description struct that specifies the names and
+                                            * codes of all device subclasses that are available for the corresponding
+                                            * User or Player, beginning with the generic Libretro device that the
+                                            * subclasses are derived from. The second inner element of each entry is the
+                                            * total number of subclasses that are listed in the retro_controller_description.
+                                            *
+                                            * NOTE: 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 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 recommended to expose all relevant pointers through
+                                            * retro_get_memory_* as well.
+                                            *
+                                            * Can be called from retro_init and retro_load_game.
+                                            */
+#define RETRO_ENVIRONMENT_SET_GEOMETRY 37
+                                           /* const struct retro_game_geometry * --
+                                            * This environment call is similar to SET_SYSTEM_AV_INFO for changing
+                                            * video parameters, but provides a guarantee that drivers will not be
+                                            * reinitialized.
+                                            * This can only be called from within retro_run().
+                                            *
+                                            * The purpose of this call is to allow a core to alter nominal
+                                            * width/heights as well as aspect ratios on-the-fly, which can be
+                                            * useful for some emulators to change in run-time.
+                                            *
+                                            * max_width/max_height arguments are ignored and cannot be changed
+                                            * with this call as this could potentially require a reinitialization or a
+                                            * non-constant time operation.
+                                            * If max_width/max_height are to be changed, SET_SYSTEM_AV_INFO is required.
+                                            *
+                                            * A frontend must guarantee that this environment call completes in
+                                            * constant time.
+                                            */
+#define RETRO_ENVIRONMENT_GET_USERNAME 38
+                                           /* const char **
+                                            * Returns the specified username of the frontend, if specified by the user.
+                                            * This username can be used as a nickname for a core that has online facilities
+                                            * or any other mode where personalization of the user is desirable.
+                                            * The returned value can be NULL.
+                                            * If this environ callback is used by a core that requires a valid username,
+                                            * a default username should be specified by the core.
+                                            */
+#define RETRO_ENVIRONMENT_GET_LANGUAGE 39
+                                           /* unsigned * --
+                                            * Returns the specified language of the frontend, if specified by the user.
+                                            * It can be used by the core for localization purposes.
+                                            */
+#define RETRO_ENVIRONMENT_GET_CURRENT_SOFTWARE_FRAMEBUFFER (40 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* struct retro_framebuffer * --
+                                            * Returns a preallocated framebuffer which the core can use for rendering
+                                            * the frame into when not using SET_HW_RENDER.
+                                            * The framebuffer returned from this call must not be used
+                                            * after the current call to retro_run() returns.
+                                            *
+                                            * The goal of this call is to allow zero-copy behavior where a core
+                                            * can render directly into video memory, avoiding extra bandwidth cost by copying
+                                            * memory from core to video memory.
+                                            *
+                                            * If this call succeeds and the core renders into it,
+                                            * the framebuffer pointer and pitch can be passed to retro_video_refresh_t.
+                                            * If the buffer from GET_CURRENT_SOFTWARE_FRAMEBUFFER is to be used,
+                                            * the core must pass the exact
+                                            * same pointer as returned by GET_CURRENT_SOFTWARE_FRAMEBUFFER;
+                                            * i.e. passing a pointer which is offset from the
+                                            * buffer is undefined. The width, height and pitch parameters
+                                            * must also match exactly to the values obtained from GET_CURRENT_SOFTWARE_FRAMEBUFFER.
+                                            *
+                                            * It is possible for a frontend to return a different pixel format
+                                            * than the one used in SET_PIXEL_FORMAT. This can happen if the frontend
+                                            * needs to perform conversion.
+                                            *
+                                            * It is still valid for a core to render to a different buffer
+                                            * even if GET_CURRENT_SOFTWARE_FRAMEBUFFER succeeds.
+                                            *
+                                            * A frontend must make sure that the pointer obtained from this function is
+                                            * writeable (and readable).
+                                            */
+#define RETRO_ENVIRONMENT_GET_HW_RENDER_INTERFACE (41 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* const struct retro_hw_render_interface ** --
+                                            * Returns an API specific rendering interface for accessing API specific data.
+                                            * Not all HW rendering APIs support or need this.
+                                            * The contents of the returned pointer is specific to the rendering API
+                                            * being used. See the various headers like libretro_vulkan.h, etc.
+                                            *
+                                            * GET_HW_RENDER_INTERFACE cannot be called before context_reset has been called.
+                                            * Similarly, after context_destroyed callback returns,
+                                            * the contents of the HW_RENDER_INTERFACE are invalidated.
+                                            */
+#define RETRO_ENVIRONMENT_SET_SUPPORT_ACHIEVEMENTS (42 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* const bool * --
+                                            * If true, the libretro implementation supports achievements
+                                            * either via memory descriptors set with RETRO_ENVIRONMENT_SET_MEMORY_MAPS
+                                            * or via retro_get_memory_data/retro_get_memory_size.
+                                            *
+                                            * This must be called before the first call to retro_run.
+                                            */
+#define RETRO_ENVIRONMENT_SET_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE (43 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* const struct retro_hw_render_context_negotiation_interface * --
+                                            * Sets an interface which lets the libretro core negotiate with frontend how a context is created.
+                                            * The semantics of this interface depends on which API is used in SET_HW_RENDER earlier.
+                                            * This interface will be used when the frontend is trying to create a HW rendering context,
+                                            * so it will be used after SET_HW_RENDER, but before the context_reset callback.
+                                            */
+#define RETRO_ENVIRONMENT_SET_SERIALIZATION_QUIRKS 44
+                                           /* uint64_t * --
+                                            * Sets quirk flags associated with serialization. The frontend will zero any flags it doesn't
+                                            * recognize or support. Should be set in either retro_init or retro_load_game, but not both.
+                                            */
+#define RETRO_ENVIRONMENT_SET_HW_SHARED_CONTEXT (44 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* N/A (null) * --
+                                            * The frontend will try to use a 'shared' hardware context (mostly applicable
+                                            * to OpenGL) when a hardware context is being set up.
+                                            *
+                                            * Returns true if the frontend supports shared hardware contexts and false
+                                            * if the frontend does not support shared hardware contexts.
+                                            *
+                                            * This will do nothing on its own until SET_HW_RENDER env callbacks are
+                                            * being used.
+                                            */
+#define RETRO_ENVIRONMENT_GET_VFS_INTERFACE (45 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* struct retro_vfs_interface_info * --
+                                            * Gets access to the VFS interface.
+                                            * VFS presence needs to be queried prior to load_game or any
+                                            * get_system/save/other_directory being called to let front end know
+                                            * core supports VFS before it starts handing out paths.
+                                            * It is recomended to do so in retro_set_environment
+                                            */
+#define RETRO_ENVIRONMENT_GET_LED_INTERFACE (46 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* struct retro_led_interface * --
+                                            * Gets an interface which is used by a libretro core to set
+                                            * state of LEDs.
+                                            */
+#define RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE (47 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* int * --
+                                            * Tells the core if the frontend wants audio or video.
+                                            * If disabled, the frontend will discard the audio or video,
+                                            * so the core may decide to skip generating a frame or generating audio.
+                                            * This is mainly used for increasing performance.
+                                            * Bit 0 (value 1): Enable Video
+                                            * Bit 1 (value 2): Enable Audio
+                                            * Bit 2 (value 4): Use Fast Savestates.
+                                            * Bit 3 (value 8): Hard Disable Audio
+                                            * Other bits are reserved for future use and will default to zero.
+                                            * If video is disabled:
+                                            * * The frontend wants the core to not generate any video,
+                                            *   including presenting frames via hardware acceleration.
+                                            * * The frontend's video frame callback will do nothing.
+                                            * * After running the frame, the video output of the next frame should be
+                                            *   no different than if video was enabled, and saving and loading state
+                                            *   should have no issues.
+                                            * If audio is disabled:
+                                            * * The frontend wants the core to not generate any audio.
+                                            * * The frontend's audio callbacks will do nothing.
+                                            * * After running the frame, the audio output of the next frame should be
+                                            *   no different than if audio was enabled, and saving and loading state
+                                            *   should have no issues.
+                                            * Fast Savestates:
+                                            * * Guaranteed to be created by the same binary that will load them.
+                                            * * Will not be written to or read from the disk.
+                                            * * Suggest that the core assumes loading state will succeed.
+                                            * * Suggest that the core updates its memory buffers in-place if possible.
+                                            * * Suggest that the core skips clearing memory.
+                                            * * Suggest that the core skips resetting the system.
+                                            * * Suggest that the core may skip validation steps.
+                                            * Hard Disable Audio:
+                                            * * Used for a secondary core when running ahead.
+                                            * * Indicates that the frontend will never need audio from the core.
+                                            * * Suggests that the core may stop synthesizing audio, but this should not
+                                            *   compromise emulation accuracy.
+                                            * * Audio output for the next frame does not matter, and the frontend will
+                                            *   never need an accurate audio state in the future.
+                                            * * State will never be saved when using Hard Disable Audio.
+                                            */
+#define RETRO_ENVIRONMENT_GET_MIDI_INTERFACE (48 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           /* struct retro_midi_interface ** --
+                                            * Returns a MIDI interface that can be used for raw data I/O.
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_FASTFORWARDING (49 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                            /* bool * --
+                                            * Boolean value that indicates whether or not the frontend is in
+                                            * fastforwarding mode.
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_TARGET_REFRESH_RATE (50 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                            /* float * --
+                                            * Float value that lets us know what target refresh rate
+                                            * is curently in use by the frontend.
+                                            *
+                                            * The core can use the returned value to set an ideal
+                                            * refresh rate/framerate.
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_INPUT_BITMASKS (51 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                            /* bool * --
+                                            * Boolean value that indicates whether or not the frontend supports
+                                            * input bitmasks being returned by retro_input_state_t. The advantage
+                                            * of this is that retro_input_state_t has to be only called once to
+                                            * grab all button states instead of multiple times.
+                                            *
+                                            * If it returns true, you can pass RETRO_DEVICE_ID_JOYPAD_MASK as 'id'
+                                            * to retro_input_state_t (make sure 'device' is set to RETRO_DEVICE_JOYPAD).
+                                            * It will return a bitmask of all the digital buttons.
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_CORE_OPTIONS_VERSION 52
+                                           /* unsigned * --
+                                            * Unsigned value is the API version number of the core options
+                                            * interface supported by the frontend. If callback return false,
+                                            * API version is assumed to be 0.
+                                            *
+                                            * In legacy code, core options are set by passing an array of
+                                            * retro_variable structs to RETRO_ENVIRONMENT_SET_VARIABLES.
+                                            * This may be still be done regardless of the core options
+                                            * interface version.
+                                            *
+                                            * If version is >= 1 however, core options may instead be set by
+                                            * passing an array of retro_core_option_definition structs to
+                                            * RETRO_ENVIRONMENT_SET_CORE_OPTIONS, or a 2D array of
+                                            * retro_core_option_definition structs to RETRO_ENVIRONMENT_SET_CORE_OPTIONS_INTL.
+                                            * This allows the core to additionally set option sublabel information
+                                            * and/or provide localisation support.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_CORE_OPTIONS 53
+                                           /* const struct retro_core_option_definition ** --
+                                            * Allows an implementation to signal the environment
+                                            * which variables it might want to check for later using
+                                            * GET_VARIABLE.
+                                            * This allows the frontend to present these variables to
+                                            * a user dynamically.
+                                            * This should only be called if RETRO_ENVIRONMENT_GET_CORE_OPTIONS_VERSION
+                                            * returns an API version of >= 1.
+                                            * This should be called instead of RETRO_ENVIRONMENT_SET_VARIABLES.
+                                            * This should be called the first time as early as
+                                            * possible (ideally in retro_set_environment).
+                                            * Afterwards it may be called again for the core to communicate
+                                            * updated options to the frontend, but the number of core
+                                            * options must not change from the number in the initial call.
+                                            *
+                                            * 'data' points to an array of retro_core_option_definition structs
+                                            * terminated by a { NULL, NULL, NULL, {{0}}, NULL } element.
+                                            * retro_core_option_definition::key should be namespaced to not collide
+                                            * with other implementations' keys. e.g. A core called
+                                            * 'foo' should use keys named as 'foo_option'.
+                                            * retro_core_option_definition::desc should contain a human readable
+                                            * description of the key.
+                                            * retro_core_option_definition::info should contain any additional human
+                                            * readable information text that a typical user may need to
+                                            * understand the functionality of the option.
+                                            * retro_core_option_definition::values is an array of retro_core_option_value
+                                            * structs terminated by a { NULL, NULL } element.
+                                            * > retro_core_option_definition::values[index].value is an expected option
+                                            *   value.
+                                            * > retro_core_option_definition::values[index].label is a human readable
+                                            *   label used when displaying the value on screen. If NULL,
+                                            *   the value itself is used.
+                                            * retro_core_option_definition::default_value is the default core option
+                                            * setting. It must match one of the expected option values in the
+                                            * retro_core_option_definition::values array. If it does not, or the
+                                            * default value is NULL, the first entry in the
+                                            * retro_core_option_definition::values array is treated as the default.
+                                            *
+                                            * The number of possible options should be very limited,
+                                            * and must be less than RETRO_NUM_CORE_OPTION_VALUES_MAX.
+                                            * i.e. it should be feasible to cycle through options
+                                            * without a keyboard.
+                                            *
+                                            * Example entry:
+                                            * {
+                                            *     "foo_option",
+                                            *     "Speed hack coprocessor X",
+                                            *     "Provides increased performance at the expense of reduced accuracy",
+                                            * 	  {
+                                            *         { "false",    NULL },
+                                            *         { "true",     NULL },
+                                            *         { "unstable", "Turbo (Unstable)" },
+                                            *         { NULL, NULL },
+                                            *     },
+                                            *     "false"
+                                            * }
+                                            *
+                                            * Only strings are operated on. The possible values will
+                                            * generally be displayed and stored as-is by the frontend.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_CORE_OPTIONS_INTL 54
+                                           /* const struct retro_core_options_intl * --
+                                            * Allows an implementation to signal the environment
+                                            * which variables it might want to check for later using
+                                            * GET_VARIABLE.
+                                            * This allows the frontend to present these variables to
+                                            * a user dynamically.
+                                            * This should only be called if RETRO_ENVIRONMENT_GET_CORE_OPTIONS_VERSION
+                                            * returns an API version of >= 1.
+                                            * This should be called instead of RETRO_ENVIRONMENT_SET_VARIABLES.
+                                            * This should be called the first time as early as
+                                            * possible (ideally in retro_set_environment).
+                                            * Afterwards it may be called again for the core to communicate
+                                            * updated options to the frontend, but the number of core
+                                            * options must not change from the number in the initial call.
+                                            *
+                                            * This is fundamentally the same as RETRO_ENVIRONMENT_SET_CORE_OPTIONS,
+                                            * with the addition of localisation support. The description of the
+                                            * RETRO_ENVIRONMENT_SET_CORE_OPTIONS callback should be consulted
+                                            * for further details.
+                                            *
+                                            * 'data' points to a retro_core_options_intl struct.
+                                            *
+                                            * retro_core_options_intl::us is a pointer to an array of
+                                            * retro_core_option_definition structs defining the US English
+                                            * core options implementation. It must point to a valid array.
+                                            *
+                                            * retro_core_options_intl::local is a pointer to an array of
+                                            * retro_core_option_definition structs defining core options for
+                                            * the current frontend language. It may be NULL (in which case
+                                            * retro_core_options_intl::us is used by the frontend). Any items
+                                            * missing from this array will be read from retro_core_options_intl::us
+                                            * instead.
+                                            *
+                                            * NOTE: Default core option values are always taken from the
+                                            * retro_core_options_intl::us array. Any default values in
+                                            * retro_core_options_intl::local array will be ignored.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_CORE_OPTIONS_DISPLAY 55
+                                           /* struct retro_core_option_display * --
+                                            *
+                                            * Allows an implementation to signal the environment to show
+                                            * or hide a variable when displaying core options. This is
+                                            * considered a *suggestion*. The frontend is free to ignore
+                                            * this callback, and its implementation not considered mandatory.
+                                            *
+                                            * 'data' points to a retro_core_option_display struct
+                                            *
+                                            * retro_core_option_display::key is a variable identifier
+                                            * which has already been set by SET_VARIABLES/SET_CORE_OPTIONS.
+                                            *
+                                            * retro_core_option_display::visible is a boolean, specifying
+                                            * whether variable should be displayed
+                                            *
+                                            * Note that all core option variables will be set visible by
+                                            * default when calling SET_VARIABLES/SET_CORE_OPTIONS.
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_PREFERRED_HW_RENDER 56
+                                           /* unsigned * --
+                                            *
+                                            * Allows an implementation to ask frontend preferred hardware
+                                            * context to use. Core should use this information to deal
+                                            * with what specific context to request with SET_HW_RENDER.
+                                            *
+                                            * 'data' points to an unsigned variable
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_DISK_CONTROL_INTERFACE_VERSION 57
+                                           /* unsigned * --
+                                            * Unsigned value is the API version number of the disk control
+                                            * interface supported by the frontend. If callback return false,
+                                            * API version is assumed to be 0.
+                                            *
+                                            * In legacy code, the disk control interface is defined by passing
+                                            * a struct of type retro_disk_control_callback to
+                                            * RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE.
+                                            * This may be still be done regardless of the disk control
+                                            * interface version.
+                                            *
+                                            * If version is >= 1 however, the disk control interface may
+                                            * instead be defined by passing a struct of type
+                                            * retro_disk_control_ext_callback to
+                                            * RETRO_ENVIRONMENT_SET_DISK_CONTROL_EXT_INTERFACE.
+                                            * This allows the core to provide additional information about
+                                            * disk images to the frontend and/or enables extra
+                                            * disk control functionality by the frontend.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_DISK_CONTROL_EXT_INTERFACE 58
+                                           /* const struct retro_disk_control_ext_callback * --
+                                            * Sets an interface which frontend can use to eject and insert
+                                            * disk images, and also obtain information about individual
+                                            * disk image files registered by the core.
+                                            * This is used for games which consist of multiple images and
+                                            * must be manually swapped out by the user (e.g. PSX, floppy disk
+                                            * based systems).
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_MESSAGE_INTERFACE_VERSION 59
+                                           /* unsigned * --
+                                            * Unsigned value is the API version number of the message
+                                            * interface supported by the frontend. If callback returns
+                                            * false, API version is assumed to be 0.
+                                            *
+                                            * In legacy code, messages may be displayed in an
+                                            * implementation-specific manner by passing a struct
+                                            * of type retro_message to RETRO_ENVIRONMENT_SET_MESSAGE.
+                                            * This may be still be done regardless of the message
+                                            * interface version.
+                                            *
+                                            * If version is >= 1 however, messages may instead be
+                                            * displayed by passing a struct of type retro_message_ext
+                                            * to RETRO_ENVIRONMENT_SET_MESSAGE_EXT. This allows the
+                                            * core to specify message logging level, priority and
+                                            * destination (OSD, logging interface or both).
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_MESSAGE_EXT 60
+                                           /* const struct retro_message_ext * --
+                                            * Sets a message to be displayed in an implementation-specific
+                                            * manner for a certain amount of 'frames'. Additionally allows
+                                            * the core to specify message logging level, priority and
+                                            * destination (OSD, logging interface or both).
+                                            * Should not be used for trivial messages, which should simply be
+                                            * logged via RETRO_ENVIRONMENT_GET_LOG_INTERFACE (or as a
+                                            * fallback, stderr).
+                                            */
+
+#define RETRO_ENVIRONMENT_GET_INPUT_MAX_USERS 61
+                                           /* unsigned * --
+                                            * Unsigned value is the number of active input devices
+                                            * provided by the frontend. This may change between
+                                            * frames, but will remain constant for the duration
+                                            * of each frame.
+                                            * If callback returns true, a core need not poll any
+                                            * input device with an index greater than or equal to
+                                            * the number of active devices.
+                                            * If callback returns false, the number of active input
+                                            * devices is unknown. In this case, all input devices
+                                            * should be considered active.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_AUDIO_BUFFER_STATUS_CALLBACK 62
+                                           /* const struct retro_audio_buffer_status_callback * --
+                                            * Lets the core know the occupancy level of the frontend
+                                            * audio buffer. Can be used by a core to attempt frame
+                                            * skipping in order to avoid buffer under-runs.
+                                            * A core may pass NULL to disable buffer status reporting
+                                            * in the frontend.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_MINIMUM_AUDIO_LATENCY 63
+                                           /* const unsigned * --
+                                            * Sets minimum frontend audio latency in milliseconds.
+                                            * Resultant audio latency may be larger than set value,
+                                            * or smaller if a hardware limit is encountered. A frontend
+                                            * is expected to honour requests up to 512 ms.
+                                            *
+                                            * - If value is less than current frontend
+                                            *   audio latency, callback has no effect
+                                            * - If value is zero, default frontend audio
+                                            *   latency is set
+                                            *
+                                            * May be used by a core to increase audio latency and
+                                            * therefore decrease the probability of buffer under-runs
+                                            * (crackling) when performing 'intensive' operations.
+                                            * A core utilising RETRO_ENVIRONMENT_SET_AUDIO_BUFFER_STATUS_CALLBACK
+                                            * to implement audio-buffer-based frame skipping may achieve
+                                            * optimal results by setting the audio latency to a 'high'
+                                            * (typically 6x or 8x) integer multiple of the expected
+                                            * frame time.
+                                            *
+                                            * WARNING: This can only be called from within retro_run().
+                                            * Calling this can require a full reinitialization of audio
+                                            * drivers in the frontend, so it is important to call it very
+                                            * sparingly, and usually only with the users explicit consent.
+                                            * An eventual driver reinitialize will happen so that audio
+                                            * callbacks happening after this call within the same retro_run()
+                                            * call will target the newly initialized driver.
+                                            */
+
+#define RETRO_ENVIRONMENT_SET_FASTFORWARDING_OVERRIDE 64
+                                           /* const struct retro_fastforwarding_override * --
+                                            * Used by a libretro core to override the current
+                                            * fastforwarding mode of the frontend.
+                                            * If NULL is passed to this function, the frontend
+                                            * will return true if fastforwarding override
+                                            * functionality is supported (no change in
+                                            * fastforwarding state will occur in this case).
+                                            */
+
+/* VFS functionality */
+
+/* File paths:
+ * File paths passed as parameters when using this API shall be well formed UNIX-style,
+ * using "/" (unquoted forward slash) as directory separator regardless of the platform's native separator.
+ * Paths shall also include at least one forward slash ("game.bin" is an invalid path, use "./game.bin" instead).
+ * Other than the directory separator, cores shall not make assumptions about path format:
+ * "C:/path/game.bin", "http://example.com/game.bin", "#game/game.bin", "./game.bin" (without quotes) are all valid paths.
+ * Cores may replace the basename or remove path components from the end, and/or add new components;
+ * however, cores shall not append "./", "../" or multiple consecutive forward slashes ("//") to paths they request to front end.
+ * The frontend is encouraged to make such paths work as well as it can, but is allowed to give up if the core alters paths too much.
+ * Frontends are encouraged, but not required, to support native file system paths (modulo replacing the directory separator, if applicable).
+ * Cores are allowed to try using them, but must remain functional if the front rejects such requests.
+ * Cores are encouraged to use the libretro-common filestream functions for file I/O,
+ * as they seamlessly integrate with VFS, deal with directory separator replacement as appropriate
+ * and provide platform-specific fallbacks in cases where front ends do not support VFS. */
+
+/* Opaque file handle
+ * Introduced in VFS API v1 */
+struct retro_vfs_file_handle;
+
+/* Opaque directory handle
+ * Introduced in VFS API v3 */
+struct retro_vfs_dir_handle;
+
+/* File open flags
+ * Introduced in VFS API v1 */
+#define RETRO_VFS_FILE_ACCESS_READ            (1 << 0) /* Read only mode */
+#define RETRO_VFS_FILE_ACCESS_WRITE           (1 << 1) /* Write only mode, discard contents and overwrites existing file unless RETRO_VFS_FILE_ACCESS_UPDATE is also specified */
+#define RETRO_VFS_FILE_ACCESS_READ_WRITE      (RETRO_VFS_FILE_ACCESS_READ | RETRO_VFS_FILE_ACCESS_WRITE) /* Read-write mode, discard contents and overwrites existing file unless RETRO_VFS_FILE_ACCESS_UPDATE is also specified*/
+#define RETRO_VFS_FILE_ACCESS_UPDATE_EXISTING (1 << 2) /* Prevents discarding content of existing files opened for writing */
+
+/* These are only hints. The frontend may choose to ignore them. Other than RAM/CPU/etc use,
+   and how they react to unlikely external interference (for example someone else writing to that file,
+   or the file's server going down), behavior will not change. */
+#define RETRO_VFS_FILE_ACCESS_HINT_NONE              (0)
+/* Indicate that the file will be accessed many times. The frontend should aggressively cache everything. */
+#define RETRO_VFS_FILE_ACCESS_HINT_FREQUENT_ACCESS   (1 << 0)
+
+/* Seek positions */
+#define RETRO_VFS_SEEK_POSITION_START    0
+#define RETRO_VFS_SEEK_POSITION_CURRENT  1
+#define RETRO_VFS_SEEK_POSITION_END      2
+
+/* stat() result flags
+ * Introduced in VFS API v3 */
+#define RETRO_VFS_STAT_IS_VALID               (1 << 0)
+#define RETRO_VFS_STAT_IS_DIRECTORY           (1 << 1)
+#define RETRO_VFS_STAT_IS_CHARACTER_SPECIAL   (1 << 2)
+
+/* Get path from opaque handle. Returns the exact same path passed to file_open when getting the handle
+ * Introduced in VFS API v1 */
+typedef const char *(RETRO_CALLCONV *retro_vfs_get_path_t)(struct retro_vfs_file_handle *stream);
+
+/* Open a file for reading or writing. If path points to a directory, this will
+ * fail. Returns the opaque file handle, or NULL for error.
+ * Introduced in VFS API v1 */
+typedef struct retro_vfs_file_handle *(RETRO_CALLCONV *retro_vfs_open_t)(const char *path, unsigned mode, unsigned hints);
+
+/* Close the file and release its resources. Must be called if open_file returns non-NULL. Returns 0 on success, -1 on failure.
+ * Whether the call succeeds ot not, the handle passed as parameter becomes invalid and should no longer be used.
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_close_t)(struct retro_vfs_file_handle *stream);
+
+/* Return the size of the file in bytes, or -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_size_t)(struct retro_vfs_file_handle *stream);
+
+/* Truncate file to specified size. Returns 0 on success or -1 on error
+ * Introduced in VFS API v2 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_truncate_t)(struct retro_vfs_file_handle *stream, int64_t length);
+
+/* Get the current read / write position for the file. Returns -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_tell_t)(struct retro_vfs_file_handle *stream);
+
+/* Set the current read/write position for the file. Returns the new position, -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_seek_t)(struct retro_vfs_file_handle *stream, int64_t offset, int seek_position);
+
+/* Read data from a file. Returns the number of bytes read, or -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_read_t)(struct retro_vfs_file_handle *stream, void *s, uint64_t len);
+
+/* Write data to a file. Returns the number of bytes written, or -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_write_t)(struct retro_vfs_file_handle *stream, const void *s, uint64_t len);
+
+/* Flush pending writes to file, if using buffered IO. Returns 0 on sucess, or -1 on failure.
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_flush_t)(struct retro_vfs_file_handle *stream);
+
+/* Delete the specified file. Returns 0 on success, -1 on failure
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_remove_t)(const char *path);
+
+/* Rename the specified file. Returns 0 on success, -1 on failure
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_rename_t)(const char *old_path, const char *new_path);
+
+/* Stat the specified file. Retruns a bitmask of RETRO_VFS_STAT_* flags, none are set if path was not valid.
+ * Additionally stores file size in given variable, unless NULL is given.
+ * Introduced in VFS API v3 */
+typedef int (RETRO_CALLCONV *retro_vfs_stat_t)(const char *path, int32_t *size);
+
+/* Create the specified directory. Returns 0 on success, -1 on unknown failure, -2 if already exists.
+ * Introduced in VFS API v3 */
+typedef int (RETRO_CALLCONV *retro_vfs_mkdir_t)(const char *dir);
+
+/* Open the specified directory for listing. Returns the opaque dir handle, or NULL for error.
+ * Support for the include_hidden argument may vary depending on the platform.
+ * Introduced in VFS API v3 */
+typedef struct retro_vfs_dir_handle *(RETRO_CALLCONV *retro_vfs_opendir_t)(const char *dir, bool include_hidden);
+
+/* Read the directory entry at the current position, and move the read pointer to the next position.
+ * Returns true on success, false if already on the last entry.
+ * Introduced in VFS API v3 */
+typedef bool (RETRO_CALLCONV *retro_vfs_readdir_t)(struct retro_vfs_dir_handle *dirstream);
+
+/* Get the name of the last entry read. Returns a string on success, or NULL for error.
+ * The returned string pointer is valid until the next call to readdir or closedir.
+ * Introduced in VFS API v3 */
+typedef const char *(RETRO_CALLCONV *retro_vfs_dirent_get_name_t)(struct retro_vfs_dir_handle *dirstream);
+
+/* Check if the last entry read was a directory. Returns true if it was, false otherwise (or on error).
+ * Introduced in VFS API v3 */
+typedef bool (RETRO_CALLCONV *retro_vfs_dirent_is_dir_t)(struct retro_vfs_dir_handle *dirstream);
+
+/* Close the directory and release its resources. Must be called if opendir returns non-NULL. Returns 0 on success, -1 on failure.
+ * Whether the call succeeds ot not, the handle passed as parameter becomes invalid and should no longer be used.
+ * Introduced in VFS API v3 */
+typedef int (RETRO_CALLCONV *retro_vfs_closedir_t)(struct retro_vfs_dir_handle *dirstream);
+
+struct retro_vfs_interface
+{
+   /* VFS API v1 */
+	retro_vfs_get_path_t get_path;
+	retro_vfs_open_t open;
+	retro_vfs_close_t close;
+	retro_vfs_size_t size;
+	retro_vfs_tell_t tell;
+	retro_vfs_seek_t seek;
+	retro_vfs_read_t read;
+	retro_vfs_write_t write;
+	retro_vfs_flush_t flush;
+	retro_vfs_remove_t remove;
+	retro_vfs_rename_t rename;
+   /* VFS API v2 */
+   retro_vfs_truncate_t truncate;
+   /* VFS API v3 */
+   retro_vfs_stat_t stat;
+   retro_vfs_mkdir_t mkdir;
+   retro_vfs_opendir_t opendir;
+   retro_vfs_readdir_t readdir;
+   retro_vfs_dirent_get_name_t dirent_get_name;
+   retro_vfs_dirent_is_dir_t dirent_is_dir;
+   retro_vfs_closedir_t closedir;
+};
+
+struct retro_vfs_interface_info
+{
+   /* Set by core: should this be higher than the version the front end supports,
+    * front end will return false in the RETRO_ENVIRONMENT_GET_VFS_INTERFACE call
+    * Introduced in VFS API v1 */
+   uint32_t required_interface_version;
+
+   /* Frontend writes interface pointer here. The frontend also sets the actual
+    * version, must be at least required_interface_version.
+    * Introduced in VFS API v1 */
+   struct retro_vfs_interface *iface;
+};
+
+enum retro_hw_render_interface_type
+{
+	RETRO_HW_RENDER_INTERFACE_VULKAN = 0,
+	RETRO_HW_RENDER_INTERFACE_D3D9   = 1,
+	RETRO_HW_RENDER_INTERFACE_D3D10  = 2,
+	RETRO_HW_RENDER_INTERFACE_D3D11  = 3,
+	RETRO_HW_RENDER_INTERFACE_D3D12  = 4,
+   RETRO_HW_RENDER_INTERFACE_GSKIT_PS2  = 5,
+   RETRO_HW_RENDER_INTERFACE_DUMMY  = INT_MAX
+};
+
+/* Base struct. All retro_hw_render_interface_* types
+ * contain at least these fields. */
+struct retro_hw_render_interface
+{
+   enum retro_hw_render_interface_type interface_type;
+   unsigned interface_version;
+};
+
+typedef void (RETRO_CALLCONV *retro_set_led_state_t)(int led, int state);
+struct retro_led_interface
+{
+    retro_set_led_state_t set_led_state;
+};
+
+/* Retrieves the current state of the MIDI input.
+ * Returns true if it's enabled, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_input_enabled_t)(void);
+
+/* Retrieves the current state of the MIDI output.
+ * Returns true if it's enabled, false otherwise */
+typedef bool (RETRO_CALLCONV *retro_midi_output_enabled_t)(void);
+
+/* Reads next byte from the input stream.
+ * Returns true if byte is read, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_read_t)(uint8_t *byte);
+
+/* Writes byte to the output stream.
+ * 'delta_time' is in microseconds and represent time elapsed since previous write.
+ * Returns true if byte is written, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_write_t)(uint8_t byte, uint32_t delta_time);
+
+/* Flushes previously written data.
+ * Returns true if successful, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_flush_t)(void);
+
+struct retro_midi_interface
+{
+   retro_midi_input_enabled_t input_enabled;
+   retro_midi_output_enabled_t output_enabled;
+   retro_midi_read_t read;
+   retro_midi_write_t write;
+   retro_midi_flush_t flush;
+};
+
+enum retro_hw_render_context_negotiation_interface_type
+{
+   RETRO_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE_VULKAN = 0,
+   RETRO_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE_DUMMY = INT_MAX
+};
+
+/* Base struct. All retro_hw_render_context_negotiation_interface_* types
+ * contain at least these fields. */
+struct retro_hw_render_context_negotiation_interface
+{
+   enum retro_hw_render_context_negotiation_interface_type interface_type;
+   unsigned interface_version;
+};
+
+/* Serialized state is incomplete in some way. Set if serialization is
+ * usable in typical end-user cases but should not be relied upon to
+ * implement frame-sensitive frontend features such as netplay or
+ * rerecording. */
+#define RETRO_SERIALIZATION_QUIRK_INCOMPLETE (1 << 0)
+/* The core must spend some time initializing before serialization is
+ * supported. retro_serialize() will initially fail; retro_unserialize()
+ * and retro_serialize_size() may or may not work correctly either. */
+#define RETRO_SERIALIZATION_QUIRK_MUST_INITIALIZE (1 << 1)
+/* Serialization size may change within a session. */
+#define RETRO_SERIALIZATION_QUIRK_CORE_VARIABLE_SIZE (1 << 2)
+/* Set by the frontend to acknowledge that it supports variable-sized
+ * states. */
+#define RETRO_SERIALIZATION_QUIRK_FRONT_VARIABLE_SIZE (1 << 3)
+/* Serialized state can only be loaded during the same session. */
+#define RETRO_SERIALIZATION_QUIRK_SINGLE_SESSION (1 << 4)
+/* Serialized state cannot be loaded on an architecture with a different
+ * endianness from the one it was saved on. */
+#define RETRO_SERIALIZATION_QUIRK_ENDIAN_DEPENDENT (1 << 5)
+/* Serialized state cannot be loaded on a different platform from the one it
+ * was saved on for reasons other than endianness, such as word size
+ * dependence */
+#define RETRO_SERIALIZATION_QUIRK_PLATFORM_DEPENDENT (1 << 6)
+
+#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_SYSTEM_RAM (1 << 2)   /* The memory area is system RAM.  This is main RAM of the gaming system. */
+#define RETRO_MEMDESC_SAVE_RAM   (1 << 3)   /* The memory area is save RAM. This RAM is usually found on a game cartridge, backed up by a battery. */
+#define RETRO_MEMDESC_VIDEO_RAM  (1 << 4)   /* The memory area is video RAM (VRAM) */
+#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;
+
+   /* 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.
+    * 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 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;
+
+   /* TODO: When finalizing this one, add a description field, which should be
+    * "WRAM" or something roughly equally long. */
+
+   /* TODO: When finalizing this one, replace 'select' with 'limit', which tells
+    * which bits can vary and still refer to the same address (limit = ~select).
+    * TODO: limit? range? vary? something else? */
+
+   /* TODO: When finalizing this one, if 'len' is above what 'select' (or
+    * 'limit') allows, it's bankswitched. Bankswitched data must have both 'len'
+    * and 'select' != 0, and the mappings don't tell how the system switches the
+    * banks. */
+
+   /* TODO: When finalizing this one, fix the 'len' bit removal order.
+    * For len=0x1800, pointer 0x1C00 should go to 0x1400, not 0x0C00.
+    * Algorithm: Take bits highest to lowest, but if it goes above len, clear
+    * the most recent addition and continue on the next bit.
+    * TODO: Can the above be optimized? Is "remove the lowest bit set in both
+    * pointer and 'len'" equivalent? */
+
+   /* TODO: Some emulators (MAME?) emulate big endian systems by only accessing
+    * the emulated memory in 32-bit chunks, native endian. But that's nothing
+    * compared to Darek Mihocka <http://www.emulators.com/docs/nx07_vm101.htm>
+    * (section Emulation 103 - Nearly Free Byte Reversal) - he flips the ENTIRE
+    * RAM backwards! I'll want to represent both of those, via some flags.
+    *
+    * I suspect MAME either didn't think of that idea, or don't want the #ifdef.
+    * Not sure which, nor do I really care. */
+
+   /* TODO: Some of those flags are unused and/or don't really make sense. Clean
+    * them up. */
+};
+
+/* 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
+{
+   /* Human-readable description of the controller. Even if using a generic
+    * input device type, this can be set to the particular device type the
+    * core uses. */
+   const char *desc;
+
+   /* Device type passed to retro_set_controller_port_device(). If the device
+    * type is a sub-class of a generic input device type, use the
+    * RETRO_DEVICE_SUBCLASS macro to create an ID.
+    *
+    * E.g. RETRO_DEVICE_SUBCLASS(RETRO_DEVICE_JOYPAD, 1). */
+   unsigned id;
+};
+
+struct retro_controller_info
+{
+   const struct retro_controller_description *types;
+   unsigned num_types;
+};
+
+struct retro_subsystem_memory_info
+{
+   /* The extension associated with a memory type, e.g. "psram". */
+   const char *extension;
+
+   /* The memory type for retro_get_memory(). This should be at
+    * least 0x100 to avoid conflict with standardized
+    * libretro memory types. */
+   unsigned type;
+};
+
+struct retro_subsystem_rom_info
+{
+   /* Describes what the content is (SGB BIOS, GB ROM, etc). */
+   const char *desc;
+
+   /* Same definition as retro_get_system_info(). */
+   const char *valid_extensions;
+
+   /* Same definition as retro_get_system_info(). */
+   bool need_fullpath;
+
+   /* Same definition as retro_get_system_info(). */
+   bool block_extract;
+
+   /* This is set if the content is required to load a game.
+    * If this is set to false, a zeroed-out retro_game_info can be passed. */
+   bool required;
+
+   /* Content can have multiple associated persistent
+    * memory types (retro_get_memory()). */
+   const struct retro_subsystem_memory_info *memory;
+   unsigned num_memory;
+};
+
+struct retro_subsystem_info
+{
+   /* Human-readable string of the subsystem type, e.g. "Super GameBoy" */
+   const char *desc;
+
+   /* A computer friendly short string identifier for the subsystem type.
+    * This name must be [a-z].
+    * E.g. if desc is "Super GameBoy", this can be "sgb".
+    * This identifier can be used for command-line interfaces, etc.
+    */
+   const char *ident;
+
+   /* Infos for each content file. The first entry is assumed to be the
+    * "most significant" content for frontend purposes.
+    * E.g. with Super GameBoy, the first content should be the GameBoy ROM,
+    * as it is the most "significant" content to a user.
+    * If a frontend creates new file paths based on the content used
+    * (e.g. savestates), it should use the path for the first ROM to do so. */
+   const struct retro_subsystem_rom_info *roms;
+
+   /* Number of content files associated with a subsystem. */
+   unsigned num_roms;
+
+   /* The type passed to retro_load_game_special(). */
+   unsigned id;
+};
+
+typedef void (RETRO_CALLCONV *retro_proc_address_t)(void);
+
+/* libretro API extension functions:
+ * (None here so far).
+ *
+ * Get a symbol from a libretro core.
+ * Cores should only return symbols which are actual
+ * extensions to the libretro API.
+ *
+ * Frontends should not use this to obtain symbols to standard
+ * libretro entry points (static linking or dlsym).
+ *
+ * The symbol name must be equal to the function name,
+ * e.g. if void retro_foo(void); exists, the symbol must be called "retro_foo".
+ * The returned function pointer must be cast to the corresponding type.
+ */
+typedef retro_proc_address_t (RETRO_CALLCONV *retro_get_proc_address_t)(const char *sym);
+
+struct retro_get_proc_address_interface
+{
+   retro_get_proc_address_t get_proc_address;
+};
+
+enum retro_log_level
+{
+   RETRO_LOG_DEBUG = 0,
+   RETRO_LOG_INFO,
+   RETRO_LOG_WARN,
+   RETRO_LOG_ERROR,
+
+   RETRO_LOG_DUMMY = INT_MAX
+};
+
+/* Logging function. Takes log level argument as well. */
+typedef void (RETRO_CALLCONV *retro_log_printf_t)(enum retro_log_level level,
+      const char *fmt, ...);
+
+struct retro_log_callback
+{
+   retro_log_printf_t log;
+};
+
+/* Performance related functions */
+
+/* ID values for SIMD CPU features */
+#define RETRO_SIMD_SSE      (1 << 0)
+#define RETRO_SIMD_SSE2     (1 << 1)
+#define RETRO_SIMD_VMX      (1 << 2)
+#define RETRO_SIMD_VMX128   (1 << 3)
+#define RETRO_SIMD_AVX      (1 << 4)
+#define RETRO_SIMD_NEON     (1 << 5)
+#define RETRO_SIMD_SSE3     (1 << 6)
+#define RETRO_SIMD_SSSE3    (1 << 7)
+#define RETRO_SIMD_MMX      (1 << 8)
+#define RETRO_SIMD_MMXEXT   (1 << 9)
+#define RETRO_SIMD_SSE4     (1 << 10)
+#define RETRO_SIMD_SSE42    (1 << 11)
+#define RETRO_SIMD_AVX2     (1 << 12)
+#define RETRO_SIMD_VFPU     (1 << 13)
+#define RETRO_SIMD_PS       (1 << 14)
+#define RETRO_SIMD_AES      (1 << 15)
+#define RETRO_SIMD_VFPV3    (1 << 16)
+#define RETRO_SIMD_VFPV4    (1 << 17)
+#define RETRO_SIMD_POPCNT   (1 << 18)
+#define RETRO_SIMD_MOVBE    (1 << 19)
+#define RETRO_SIMD_CMOV     (1 << 20)
+#define RETRO_SIMD_ASIMD    (1 << 21)
+
+typedef uint64_t retro_perf_tick_t;
+typedef int64_t retro_time_t;
+
+struct retro_perf_counter
+{
+   const char *ident;
+   retro_perf_tick_t start;
+   retro_perf_tick_t total;
+   retro_perf_tick_t call_cnt;
+
+   bool registered;
+};
+
+/* Returns current time in microseconds.
+ * Tries to use the most accurate timer available.
+ */
+typedef retro_time_t (RETRO_CALLCONV *retro_perf_get_time_usec_t)(void);
+
+/* A simple counter. Usually nanoseconds, but can also be CPU cycles.
+ * Can be used directly if desired (when creating a more sophisticated
+ * performance counter system).
+ * */
+typedef retro_perf_tick_t (RETRO_CALLCONV *retro_perf_get_counter_t)(void);
+
+/* Returns a bit-mask of detected CPU features (RETRO_SIMD_*). */
+typedef uint64_t (RETRO_CALLCONV *retro_get_cpu_features_t)(void);
+
+/* Asks frontend to log and/or display the state of performance counters.
+ * Performance counters can always be poked into manually as well.
+ */
+typedef void (RETRO_CALLCONV *retro_perf_log_t)(void);
+
+/* Register a performance counter.
+ * ident field must be set with a discrete value and other values in
+ * retro_perf_counter must be 0.
+ * Registering can be called multiple times. To avoid calling to
+ * frontend redundantly, you can check registered field first. */
+typedef void (RETRO_CALLCONV *retro_perf_register_t)(struct retro_perf_counter *counter);
+
+/* Starts a registered counter. */
+typedef void (RETRO_CALLCONV *retro_perf_start_t)(struct retro_perf_counter *counter);
+
+/* Stops a registered counter. */
+typedef void (RETRO_CALLCONV *retro_perf_stop_t)(struct retro_perf_counter *counter);
+
+/* For convenience it can be useful to wrap register, start and stop in macros.
+ * E.g.:
+ * #ifdef LOG_PERFORMANCE
+ * #define RETRO_PERFORMANCE_INIT(perf_cb, name) static struct retro_perf_counter name = {#name}; if (!name.registered) perf_cb.perf_register(&(name))
+ * #define RETRO_PERFORMANCE_START(perf_cb, name) perf_cb.perf_start(&(name))
+ * #define RETRO_PERFORMANCE_STOP(perf_cb, name) perf_cb.perf_stop(&(name))
+ * #else
+ * ... Blank macros ...
+ * #endif
+ *
+ * These can then be used mid-functions around code snippets.
+ *
+ * extern struct retro_perf_callback perf_cb;  * Somewhere in the core.
+ *
+ * void do_some_heavy_work(void)
+ * {
+ *    RETRO_PERFORMANCE_INIT(cb, work_1;
+ *    RETRO_PERFORMANCE_START(cb, work_1);
+ *    heavy_work_1();
+ *    RETRO_PERFORMANCE_STOP(cb, work_1);
+ *
+ *    RETRO_PERFORMANCE_INIT(cb, work_2);
+ *    RETRO_PERFORMANCE_START(cb, work_2);
+ *    heavy_work_2();
+ *    RETRO_PERFORMANCE_STOP(cb, work_2);
+ * }
+ *
+ * void retro_deinit(void)
+ * {
+ *    perf_cb.perf_log();  * Log all perf counters here for example.
+ * }
+ */
+
+struct retro_perf_callback
+{
+   retro_perf_get_time_usec_t    get_time_usec;
+   retro_get_cpu_features_t      get_cpu_features;
+
+   retro_perf_get_counter_t      get_perf_counter;
+   retro_perf_register_t         perf_register;
+   retro_perf_start_t            perf_start;
+   retro_perf_stop_t             perf_stop;
+   retro_perf_log_t              perf_log;
+};
+
+/* FIXME: Document the sensor API and work out behavior.
+ * It will be marked as experimental until then.
+ */
+enum retro_sensor_action
+{
+   RETRO_SENSOR_ACCELEROMETER_ENABLE = 0,
+   RETRO_SENSOR_ACCELEROMETER_DISABLE,
+   RETRO_SENSOR_GYROSCOPE_ENABLE,
+   RETRO_SENSOR_GYROSCOPE_DISABLE,
+   RETRO_SENSOR_ILLUMINANCE_ENABLE,
+   RETRO_SENSOR_ILLUMINANCE_DISABLE,
+
+   RETRO_SENSOR_DUMMY = INT_MAX
+};
+
+/* Id values for SENSOR types. */
+#define RETRO_SENSOR_ACCELEROMETER_X 0
+#define RETRO_SENSOR_ACCELEROMETER_Y 1
+#define RETRO_SENSOR_ACCELEROMETER_Z 2
+#define RETRO_SENSOR_GYROSCOPE_X 3
+#define RETRO_SENSOR_GYROSCOPE_Y 4
+#define RETRO_SENSOR_GYROSCOPE_Z 5
+#define RETRO_SENSOR_ILLUMINANCE 6
+
+typedef bool (RETRO_CALLCONV *retro_set_sensor_state_t)(unsigned port,
+      enum retro_sensor_action action, unsigned rate);
+
+typedef float (RETRO_CALLCONV *retro_sensor_get_input_t)(unsigned port, unsigned id);
+
+struct retro_sensor_interface
+{
+   retro_set_sensor_state_t set_sensor_state;
+   retro_sensor_get_input_t get_sensor_input;
+};
+
+enum retro_camera_buffer
+{
+   RETRO_CAMERA_BUFFER_OPENGL_TEXTURE = 0,
+   RETRO_CAMERA_BUFFER_RAW_FRAMEBUFFER,
+
+   RETRO_CAMERA_BUFFER_DUMMY = INT_MAX
+};
+
+/* Starts the camera driver. Can only be called in retro_run(). */
+typedef bool (RETRO_CALLCONV *retro_camera_start_t)(void);
+
+/* Stops the camera driver. Can only be called in retro_run(). */
+typedef void (RETRO_CALLCONV *retro_camera_stop_t)(void);
+
+/* Callback which signals when the camera driver is initialized
+ * and/or deinitialized.
+ * retro_camera_start_t can be called in initialized callback.
+ */
+typedef void (RETRO_CALLCONV *retro_camera_lifetime_status_t)(void);
+
+/* A callback for raw framebuffer data. buffer points to an XRGB8888 buffer.
+ * Width, height and pitch are similar to retro_video_refresh_t.
+ * First pixel is top-left origin.
+ */
+typedef void (RETRO_CALLCONV *retro_camera_frame_raw_framebuffer_t)(const uint32_t *buffer,
+      unsigned width, unsigned height, size_t pitch);
+
+/* A callback for when OpenGL textures are used.
+ *
+ * texture_id is a texture owned by camera driver.
+ * Its state or content should be considered immutable, except for things like
+ * texture filtering and clamping.
+ *
+ * texture_target is the texture target for the GL texture.
+ * These can include e.g. GL_TEXTURE_2D, GL_TEXTURE_RECTANGLE, and possibly
+ * more depending on extensions.
+ *
+ * affine points to a packed 3x3 column-major matrix used to apply an affine
+ * transform to texture coordinates. (affine_matrix * vec3(coord_x, coord_y, 1.0))
+ * After transform, normalized texture coord (0, 0) should be bottom-left
+ * and (1, 1) should be top-right (or (width, height) for RECTANGLE).
+ *
+ * GL-specific typedefs are avoided here to avoid relying on gl.h in
+ * the API definition.
+ */
+typedef void (RETRO_CALLCONV *retro_camera_frame_opengl_texture_t)(unsigned texture_id,
+      unsigned texture_target, const float *affine);
+
+struct retro_camera_callback
+{
+   /* Set by libretro core.
+    * Example bitmask: caps = (1 << RETRO_CAMERA_BUFFER_OPENGL_TEXTURE) | (1 << RETRO_CAMERA_BUFFER_RAW_FRAMEBUFFER).
+    */
+   uint64_t caps;
+
+   /* Desired resolution for camera. Is only used as a hint. */
+   unsigned width;
+   unsigned height;
+
+   /* Set by frontend. */
+   retro_camera_start_t start;
+   retro_camera_stop_t stop;
+
+   /* Set by libretro core if raw framebuffer callbacks will be used. */
+   retro_camera_frame_raw_framebuffer_t frame_raw_framebuffer;
+
+   /* Set by libretro core if OpenGL texture callbacks will be used. */
+   retro_camera_frame_opengl_texture_t frame_opengl_texture;
+
+   /* Set by libretro core. Called after camera driver is initialized and
+    * ready to be started.
+    * Can be NULL, in which this callback is not called.
+    */
+   retro_camera_lifetime_status_t initialized;
+
+   /* Set by libretro core. Called right before camera driver is
+    * deinitialized.
+    * Can be NULL, in which this callback is not called.
+    */
+   retro_camera_lifetime_status_t deinitialized;
+};
+
+/* Sets the interval of time and/or distance at which to update/poll
+ * location-based data.
+ *
+ * To ensure compatibility with all location-based implementations,
+ * values for both interval_ms and interval_distance should be provided.
+ *
+ * interval_ms is the interval expressed in milliseconds.
+ * interval_distance is the distance interval expressed in meters.
+ */
+typedef void (RETRO_CALLCONV *retro_location_set_interval_t)(unsigned interval_ms,
+      unsigned interval_distance);
+
+/* Start location services. The device will start listening for changes to the
+ * current location at regular intervals (which are defined with
+ * retro_location_set_interval_t). */
+typedef bool (RETRO_CALLCONV *retro_location_start_t)(void);
+
+/* Stop location services. The device will stop listening for changes
+ * to the current location. */
+typedef void (RETRO_CALLCONV *retro_location_stop_t)(void);
+
+/* Get the position of the current location. Will set parameters to
+ * 0 if no new  location update has happened since the last time. */
+typedef bool (RETRO_CALLCONV *retro_location_get_position_t)(double *lat, double *lon,
+      double *horiz_accuracy, double *vert_accuracy);
+
+/* Callback which signals when the location driver is initialized
+ * and/or deinitialized.
+ * retro_location_start_t can be called in initialized callback.
+ */
+typedef void (RETRO_CALLCONV *retro_location_lifetime_status_t)(void);
+
+struct retro_location_callback
+{
+   retro_location_start_t         start;
+   retro_location_stop_t          stop;
+   retro_location_get_position_t  get_position;
+   retro_location_set_interval_t  set_interval;
+
+   retro_location_lifetime_status_t initialized;
+   retro_location_lifetime_status_t deinitialized;
+};
+
+enum retro_rumble_effect
+{
+   RETRO_RUMBLE_STRONG = 0,
+   RETRO_RUMBLE_WEAK = 1,
+
+   RETRO_RUMBLE_DUMMY = INT_MAX
+};
+
+/* Sets rumble state for joypad plugged in port 'port'.
+ * Rumble effects are controlled independently,
+ * and setting e.g. strong rumble does not override weak rumble.
+ * Strength has a range of [0, 0xffff].
+ *
+ * Returns true if rumble state request was honored.
+ * Calling this before first retro_run() is likely to return false. */
+typedef bool (RETRO_CALLCONV *retro_set_rumble_state_t)(unsigned port,
+      enum retro_rumble_effect effect, uint16_t strength);
+
+struct retro_rumble_interface
+{
+   retro_set_rumble_state_t set_rumble_state;
+};
+
+/* Notifies libretro that audio data should be written. */
+typedef void (RETRO_CALLCONV *retro_audio_callback_t)(void);
+
+/* True: Audio driver in frontend is active, and callback is
+ * expected to be called regularily.
+ * False: Audio driver in frontend is paused or inactive.
+ * Audio callback will not be called until set_state has been
+ * called with true.
+ * Initial state is false (inactive).
+ */
+typedef void (RETRO_CALLCONV *retro_audio_set_state_callback_t)(bool enabled);
+
+struct retro_audio_callback
+{
+   retro_audio_callback_t callback;
+   retro_audio_set_state_callback_t set_state;
+};
+
+/* Notifies a libretro core of time spent since last invocation
+ * of retro_run() in microseconds.
+ *
+ * It will be called right before retro_run() every frame.
+ * The frontend can tamper with timing to support cases like
+ * fast-forward, slow-motion and framestepping.
+ *
+ * In those scenarios the reference frame time value will be used. */
+typedef int64_t retro_usec_t;
+typedef void (RETRO_CALLCONV *retro_frame_time_callback_t)(retro_usec_t usec);
+struct retro_frame_time_callback
+{
+   retro_frame_time_callback_t callback;
+   /* Represents the time of one frame. It is computed as
+    * 1000000 / fps, but the implementation will resolve the
+    * rounding to ensure that framestepping, etc is exact. */
+   retro_usec_t reference;
+};
+
+/* Notifies a libretro core of the current occupancy
+ * level of the frontend audio buffer.
+ *
+ * - active: 'true' if audio buffer is currently
+ *           in use. Will be 'false' if audio is
+ *           disabled in the frontend
+ *
+ * - occupancy: Given as a value in the range [0,100],
+ *              corresponding to the occupancy percentage
+ *              of the audio buffer
+ *
+ * - underrun_likely: 'true' if the frontend expects an
+ *                    audio buffer underrun during the
+ *                    next frame (indicates that a core
+ *                    should attempt frame skipping)
+ *
+ * It will be called right before retro_run() every frame. */
+typedef void (RETRO_CALLCONV *retro_audio_buffer_status_callback_t)(
+      bool active, unsigned occupancy, bool underrun_likely);
+struct retro_audio_buffer_status_callback
+{
+   retro_audio_buffer_status_callback_t callback;
+};
+
+/* Pass this to retro_video_refresh_t if rendering to hardware.
+ * Passing NULL to retro_video_refresh_t is still a frame dupe as normal.
+ * */
+#define RETRO_HW_FRAME_BUFFER_VALID ((void*)-1)
+
+/* Invalidates the current HW context.
+ * Any GL state is lost, and must not be deinitialized explicitly.
+ * If explicit deinitialization is desired by the libretro core,
+ * it should implement context_destroy callback.
+ * If called, all GPU resources must be reinitialized.
+ * Usually called when frontend reinits video driver.
+ * Also called first time video driver is initialized,
+ * allowing libretro core to initialize resources.
+ */
+typedef void (RETRO_CALLCONV *retro_hw_context_reset_t)(void);
+
+/* Gets current framebuffer which is to be rendered to.
+ * Could change every frame potentially.
+ */
+typedef uintptr_t (RETRO_CALLCONV *retro_hw_get_current_framebuffer_t)(void);
+
+/* Get a symbol from HW context. */
+typedef retro_proc_address_t (RETRO_CALLCONV *retro_hw_get_proc_address_t)(const char *sym);
+
+enum retro_hw_context_type
+{
+   RETRO_HW_CONTEXT_NONE             = 0,
+   /* OpenGL 2.x. Driver can choose to use latest compatibility context. */
+   RETRO_HW_CONTEXT_OPENGL           = 1,
+   /* OpenGL ES 2.0. */
+   RETRO_HW_CONTEXT_OPENGLES2        = 2,
+   /* Modern desktop core GL context. Use version_major/
+    * version_minor fields to set GL version. */
+   RETRO_HW_CONTEXT_OPENGL_CORE      = 3,
+   /* OpenGL ES 3.0 */
+   RETRO_HW_CONTEXT_OPENGLES3        = 4,
+   /* OpenGL ES 3.1+. Set version_major/version_minor. For GLES2 and GLES3,
+    * use the corresponding enums directly. */
+   RETRO_HW_CONTEXT_OPENGLES_VERSION = 5,
+
+   /* Vulkan, see RETRO_ENVIRONMENT_GET_HW_RENDER_INTERFACE. */
+   RETRO_HW_CONTEXT_VULKAN           = 6,
+
+   /* Direct3D, set version_major to select the type of interface
+    * returned by RETRO_ENVIRONMENT_GET_HW_RENDER_INTERFACE */
+   RETRO_HW_CONTEXT_DIRECT3D         = 7,
+
+   RETRO_HW_CONTEXT_DUMMY = INT_MAX
+};
+
+struct retro_hw_render_callback
+{
+   /* Which API to use. Set by libretro core. */
+   enum retro_hw_context_type context_type;
+
+   /* Called when a context has been created or when it has been reset.
+    * An OpenGL context is only valid after context_reset() has been called.
+    *
+    * When context_reset is called, OpenGL resources in the libretro
+    * implementation are guaranteed to be invalid.
+    *
+    * It is possible that context_reset is called multiple times during an
+    * application lifecycle.
+    * If context_reset is called without any notification (context_destroy),
+    * the OpenGL context was lost and resources should just be recreated
+    * without any attempt to "free" old resources.
+    */
+   retro_hw_context_reset_t context_reset;
+
+   /* Set by frontend.
+    * TODO: This is rather obsolete. The frontend should not
+    * be providing preallocated framebuffers. */
+   retro_hw_get_current_framebuffer_t get_current_framebuffer;
+
+   /* Set by frontend.
+    * Can return all relevant functions, including glClear on Windows. */
+   retro_hw_get_proc_address_t get_proc_address;
+
+   /* Set if render buffers should have depth component attached.
+    * TODO: Obsolete. */
+   bool depth;
+
+   /* Set if stencil buffers should be attached.
+    * TODO: Obsolete. */
+   bool stencil;
+
+   /* If depth and stencil are true, a packed 24/8 buffer will be added.
+    * Only attaching stencil is invalid and will be ignored. */
+
+   /* Use conventional bottom-left origin convention. If false,
+    * standard libretro top-left origin semantics are used.
+    * TODO: Move to GL specific interface. */
+   bool bottom_left_origin;
+
+   /* Major version number for core GL context or GLES 3.1+. */
+   unsigned version_major;
+
+   /* Minor version number for core GL context or GLES 3.1+. */
+   unsigned version_minor;
+
+   /* If this is true, the frontend will go very far to avoid
+    * resetting context in scenarios like toggling fullscreen, etc.
+    * TODO: Obsolete? Maybe frontend should just always assume this ...
+    */
+   bool cache_context;
+
+   /* The reset callback might still be called in extreme situations
+    * such as if the context is lost beyond recovery.
+    *
+    * For optimal stability, set this to false, and allow context to be
+    * reset at any time.
+    */
+
+   /* A callback to be called before the context is destroyed in a
+    * controlled way by the frontend. */
+   retro_hw_context_reset_t context_destroy;
+
+   /* OpenGL resources can be deinitialized cleanly at this step.
+    * context_destroy can be set to NULL, in which resources will
+    * just be destroyed without any notification.
+    *
+    * Even when context_destroy is non-NULL, it is possible that
+    * context_reset is called without any destroy notification.
+    * This happens if context is lost by external factors (such as
+    * notified by GL_ARB_robustness).
+    *
+    * In this case, the context is assumed to be already dead,
+    * and the libretro implementation must not try to free any OpenGL
+    * resources in the subsequent context_reset.
+    */
+
+   /* Creates a debug context. */
+   bool debug_context;
+};
+
+/* Callback type passed in RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK.
+ * Called by the frontend in response to keyboard events.
+ * down is set if the key is being pressed, or false if it is being released.
+ * keycode is the RETROK value of the char.
+ * character is the text character of the pressed key. (UTF-32).
+ * key_modifiers is a set of RETROKMOD values or'ed together.
+ *
+ * The pressed/keycode state can be indepedent of the character.
+ * It is also possible that multiple characters are generated from a
+ * single keypress.
+ * Keycode events should be treated separately from character events.
+ * However, when possible, the frontend should try to synchronize these.
+ * If only a character is posted, keycode should be RETROK_UNKNOWN.
+ *
+ * Similarily if only a keycode event is generated with no corresponding
+ * character, character should be 0.
+ */
+typedef void (RETRO_CALLCONV *retro_keyboard_event_t)(bool down, unsigned keycode,
+      uint32_t character, uint16_t key_modifiers);
+
+struct retro_keyboard_callback
+{
+   retro_keyboard_event_t callback;
+};
+
+/* Callbacks for RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE &
+ * RETRO_ENVIRONMENT_SET_DISK_CONTROL_EXT_INTERFACE.
+ * Should be set for implementations which can swap out multiple disk
+ * images in runtime.
+ *
+ * If the implementation can do this automatically, it should strive to do so.
+ * However, there are cases where the user must manually do so.
+ *
+ * Overview: To swap a disk image, eject the disk image with
+ * set_eject_state(true).
+ * Set the disk index with set_image_index(index). Insert the disk again
+ * with set_eject_state(false).
+ */
+
+/* If ejected is true, "ejects" the virtual disk tray.
+ * When ejected, the disk image index can be set.
+ */
+typedef bool (RETRO_CALLCONV *retro_set_eject_state_t)(bool ejected);
+
+/* Gets current eject state. The initial state is 'not ejected'. */
+typedef bool (RETRO_CALLCONV *retro_get_eject_state_t)(void);
+
+/* Gets current disk index. First disk is index 0.
+ * If return value is >= get_num_images(), no disk is currently inserted.
+ */
+typedef unsigned (RETRO_CALLCONV *retro_get_image_index_t)(void);
+
+/* Sets image index. Can only be called when disk is ejected.
+ * The implementation supports setting "no disk" by using an
+ * index >= get_num_images().
+ */
+typedef bool (RETRO_CALLCONV *retro_set_image_index_t)(unsigned index);
+
+/* Gets total number of images which are available to use. */
+typedef unsigned (RETRO_CALLCONV *retro_get_num_images_t)(void);
+
+struct retro_game_info;
+
+/* Replaces the disk image associated with index.
+ * Arguments to pass in info have same requirements as retro_load_game().
+ * Virtual disk tray must be ejected when calling this.
+ *
+ * Replacing a disk image with info = NULL will remove the disk image
+ * from the internal list.
+ * As a result, calls to get_image_index() can change.
+ *
+ * E.g. replace_image_index(1, NULL), and previous get_image_index()
+ * returned 4 before.
+ * Index 1 will be removed, and the new index is 3.
+ */
+typedef bool (RETRO_CALLCONV *retro_replace_image_index_t)(unsigned index,
+      const struct retro_game_info *info);
+
+/* Adds a new valid index (get_num_images()) to the internal disk list.
+ * This will increment subsequent return values from get_num_images() by 1.
+ * This image index cannot be used until a disk image has been set
+ * with replace_image_index. */
+typedef bool (RETRO_CALLCONV *retro_add_image_index_t)(void);
+
+/* Sets initial image to insert in drive when calling
+ * core_load_game().
+ * Since we cannot pass the initial index when loading
+ * content (this would require a major API change), this
+ * is set by the frontend *before* calling the core's
+ * retro_load_game()/retro_load_game_special() implementation.
+ * A core should therefore cache the index/path values and handle
+ * them inside retro_load_game()/retro_load_game_special().
+ * - If 'index' is invalid (index >= get_num_images()), the
+ *   core should ignore the set value and instead use 0
+ * - 'path' is used purely for error checking - i.e. when
+ *   content is loaded, the core should verify that the
+ *   disk specified by 'index' has the specified file path.
+ *   This is to guard against auto selecting the wrong image
+ *   if (for example) the user should modify an existing M3U
+ *   playlist. We have to let the core handle this because
+ *   set_initial_image() must be called before loading content,
+ *   i.e. the frontend cannot access image paths in advance
+ *   and thus cannot perform the error check itself.
+ *   If set path and content path do not match, the core should
+ *   ignore the set 'index' value and instead use 0
+ * Returns 'false' if index or 'path' are invalid, or core
+ * does not support this functionality
+ */
+typedef bool (RETRO_CALLCONV *retro_set_initial_image_t)(unsigned index, const char *path);
+
+/* Fetches the path of the specified disk image file.
+ * Returns 'false' if index is invalid (index >= get_num_images())
+ * or path is otherwise unavailable.
+ */
+typedef bool (RETRO_CALLCONV *retro_get_image_path_t)(unsigned index, char *path, size_t len);
+
+/* Fetches a core-provided 'label' for the specified disk
+ * image file. In the simplest case this may be a file name
+ * (without extension), but for cores with more complex
+ * content requirements information may be provided to
+ * facilitate user disk swapping - for example, a core
+ * running floppy-disk-based content may uniquely label
+ * save disks, data disks, level disks, etc. with names
+ * corresponding to in-game disk change prompts (so the
+ * frontend can provide better user guidance than a 'dumb'
+ * disk index value).
+ * Returns 'false' if index is invalid (index >= get_num_images())
+ * or label is otherwise unavailable.
+ */
+typedef bool (RETRO_CALLCONV *retro_get_image_label_t)(unsigned index, char *label, size_t len);
+
+struct retro_disk_control_callback
+{
+   retro_set_eject_state_t set_eject_state;
+   retro_get_eject_state_t get_eject_state;
+
+   retro_get_image_index_t get_image_index;
+   retro_set_image_index_t set_image_index;
+   retro_get_num_images_t  get_num_images;
+
+   retro_replace_image_index_t replace_image_index;
+   retro_add_image_index_t add_image_index;
+};
+
+struct retro_disk_control_ext_callback
+{
+   retro_set_eject_state_t set_eject_state;
+   retro_get_eject_state_t get_eject_state;
+
+   retro_get_image_index_t get_image_index;
+   retro_set_image_index_t set_image_index;
+   retro_get_num_images_t  get_num_images;
+
+   retro_replace_image_index_t replace_image_index;
+   retro_add_image_index_t add_image_index;
+
+   /* NOTE: Frontend will only attempt to record/restore
+    * last used disk index if both set_initial_image()
+    * and get_image_path() are implemented */
+   retro_set_initial_image_t set_initial_image; /* Optional - may be NULL */
+
+   retro_get_image_path_t get_image_path;       /* Optional - may be NULL */
+   retro_get_image_label_t get_image_label;     /* Optional - may be NULL */
+};
+
+enum retro_pixel_format
+{
+   /* 0RGB1555, native endian.
+    * 0 bit must be set to 0.
+    * This pixel format is default for compatibility concerns only.
+    * If a 15/16-bit pixel format is desired, consider using RGB565. */
+   RETRO_PIXEL_FORMAT_0RGB1555 = 0,
+
+   /* XRGB8888, native endian.
+    * X bits are ignored. */
+   RETRO_PIXEL_FORMAT_XRGB8888 = 1,
+
+   /* RGB565, native endian.
+    * This pixel format is the recommended format to use if a 15/16-bit
+    * format is desired as it is the pixel format that is typically
+    * available on a wide range of low-power devices.
+    *
+    * It is also natively supported in APIs like OpenGL ES. */
+   RETRO_PIXEL_FORMAT_RGB565   = 2,
+
+   /* Ensure sizeof() == sizeof(int). */
+   RETRO_PIXEL_FORMAT_UNKNOWN  = INT_MAX
+};
+
+struct retro_message
+{
+   const char *msg;        /* Message to be displayed. */
+   unsigned    frames;     /* Duration in frames of message. */
+};
+
+enum retro_message_target
+{
+   RETRO_MESSAGE_TARGET_ALL = 0,
+   RETRO_MESSAGE_TARGET_OSD,
+   RETRO_MESSAGE_TARGET_LOG
+};
+
+enum retro_message_type
+{
+   RETRO_MESSAGE_TYPE_NOTIFICATION = 0,
+   RETRO_MESSAGE_TYPE_NOTIFICATION_ALT,
+   RETRO_MESSAGE_TYPE_STATUS,
+   RETRO_MESSAGE_TYPE_PROGRESS
+};
+
+struct retro_message_ext
+{
+   /* Message string to be displayed/logged */
+   const char *msg;
+   /* Duration (in ms) of message when targeting the OSD */
+   unsigned duration;
+   /* Message priority when targeting the OSD
+    * > When multiple concurrent messages are sent to
+    *   the frontend and the frontend does not have the
+    *   capacity to display them all, messages with the
+    *   *highest* priority value should be shown
+    * > There is no upper limit to a message priority
+    *   value (within the bounds of the unsigned data type)
+    * > In the reference frontend (RetroArch), the same
+    *   priority values are used for frontend-generated
+    *   notifications, which are typically assigned values
+    *   between 0 and 3 depending upon importance */
+   unsigned priority;
+   /* Message logging level (info, warn, error, etc.) */
+   enum retro_log_level level;
+   /* Message destination: OSD, logging interface or both */
+   enum retro_message_target target;
+   /* Message 'type' when targeting the OSD
+    * > RETRO_MESSAGE_TYPE_NOTIFICATION: Specifies that a
+    *   message should be handled in identical fashion to
+    *   a standard frontend-generated notification
+    * > RETRO_MESSAGE_TYPE_NOTIFICATION_ALT: Specifies that
+    *   message is a notification that requires user attention
+    *   or action, but that it should be displayed in a manner
+    *   that differs from standard frontend-generated notifications.
+    *   This would typically correspond to messages that should be
+    *   displayed immediately (independently from any internal
+    *   frontend message queue), and/or which should be visually
+    *   distinguishable from frontend-generated notifications.
+    *   For example, a core may wish to inform the user of
+    *   information related to a disk-change event. It is
+    *   expected that the frontend itself may provide a
+    *   notification in this case; if the core sends a
+    *   message of type RETRO_MESSAGE_TYPE_NOTIFICATION, an
+    *   uncomfortable 'double-notification' may occur. A message
+    *   of RETRO_MESSAGE_TYPE_NOTIFICATION_ALT should therefore
+    *   be presented such that visual conflict with regular
+    *   notifications does not occur
+    * > RETRO_MESSAGE_TYPE_STATUS: Indicates that message
+    *   is not a standard notification. This typically
+    *   corresponds to 'status' indicators, such as a core's
+    *   internal FPS, which are intended to be displayed
+    *   either permanently while a core is running, or in
+    *   a manner that does not suggest user attention or action
+    *   is required. 'Status' type messages should therefore be
+    *   displayed in a different on-screen location and in a manner
+    *   easily distinguishable from both standard frontend-generated
+    *   notifications and messages of type RETRO_MESSAGE_TYPE_NOTIFICATION_ALT
+    * > RETRO_MESSAGE_TYPE_PROGRESS: Indicates that message reports
+    *   the progress of an internal core task. For example, in cases
+    *   where a core itself handles the loading of content from a file,
+    *   this may correspond to the percentage of the file that has been
+    *   read. Alternatively, an audio/video playback core may use a
+    *   message of type RETRO_MESSAGE_TYPE_PROGRESS to display the current
+    *   playback position as a percentage of the runtime. 'Progress' type
+    *   messages should therefore be displayed as a literal progress bar,
+    *   where:
+    *   - 'retro_message_ext.msg' is the progress bar title/label
+    *   - 'retro_message_ext.progress' determines the length of
+    *     the progress bar
+    * NOTE: Message type is a *hint*, and may be ignored
+    * by the frontend. If a frontend lacks support for
+    * displaying messages via alternate means than standard
+    * frontend-generated notifications, it will treat *all*
+    * messages as having the type RETRO_MESSAGE_TYPE_NOTIFICATION */
+   enum retro_message_type type;
+   /* Task progress when targeting the OSD and message is
+    * of type RETRO_MESSAGE_TYPE_PROGRESS
+    * > -1:    Unmetered/indeterminate
+    * > 0-100: Current progress percentage
+    * NOTE: Since message type is a hint, a frontend may ignore
+    * progress values. Where relevant, a core should therefore
+    * include progress percentage within the message string,
+    * such that the message intent remains clear when displayed
+    * as a standard frontend-generated notification */
+   int8_t progress;
+};
+
+/* Describes how the libretro implementation maps a libretro input bind
+ * to its internal input system through a human readable string.
+ * This string can be used to better let a user configure input. */
+struct retro_input_descriptor
+{
+   /* Associates given parameters with a description. */
+   unsigned port;
+   unsigned device;
+   unsigned index;
+   unsigned id;
+
+   /* Human readable description for parameters.
+    * The pointer must remain valid until
+    * retro_unload_game() is called. */
+   const char *description;
+};
+
+struct retro_system_info
+{
+   /* All pointers are owned by libretro implementation, and pointers must
+    * remain valid until it is unloaded. */
+
+   const char *library_name;      /* Descriptive name of library. Should not
+                                   * contain any version numbers, etc. */
+   const char *library_version;   /* Descriptive version of core. */
+
+   const char *valid_extensions;  /* A string listing probably content
+                                   * extensions the core will be able to
+                                   * load, separated with pipe.
+                                   * I.e. "bin|rom|iso".
+                                   * Typically used for a GUI to filter
+                                   * out extensions. */
+
+   /* Libretro cores that need to have direct access to their content
+    * files, including cores which use the path of the content files to
+    * determine the paths of other files, should set need_fullpath to true.
+    *
+    * Cores should strive for setting need_fullpath to false,
+    * as it allows the frontend to perform patching, etc.
+    *
+    * If need_fullpath is true and retro_load_game() is called:
+    *    - retro_game_info::path is guaranteed to have a valid path
+    *    - retro_game_info::data and retro_game_info::size are invalid
+    *
+    * If need_fullpath is false and retro_load_game() is called:
+    *    - retro_game_info::path may be NULL
+    *    - retro_game_info::data and retro_game_info::size are guaranteed
+    *      to be valid
+    *
+    * See also:
+    *    - RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY
+    *    - RETRO_ENVIRONMENT_GET_SAVE_DIRECTORY
+    */
+   bool        need_fullpath;
+
+   /* If true, the frontend is not allowed to extract any archives before
+    * loading the real content.
+    * Necessary for certain libretro implementations that load games
+    * from zipped archives. */
+   bool        block_extract;
+};
+
+struct retro_game_geometry
+{
+   unsigned base_width;    /* Nominal video width of game. */
+   unsigned base_height;   /* Nominal video height of game. */
+   unsigned max_width;     /* Maximum possible width of game. */
+   unsigned max_height;    /* Maximum possible height of game. */
+
+   float    aspect_ratio;  /* Nominal aspect ratio of game. If
+                            * aspect_ratio is <= 0.0, an aspect ratio
+                            * of base_width / base_height is assumed.
+                            * A frontend could override this setting,
+                            * if desired. */
+};
+
+struct retro_system_timing
+{
+   double fps;             /* FPS of video content. */
+   double sample_rate;     /* Sampling rate of audio. */
+};
+
+struct retro_system_av_info
+{
+   struct retro_game_geometry geometry;
+   struct retro_system_timing timing;
+};
+
+struct retro_variable
+{
+   /* Variable to query in RETRO_ENVIRONMENT_GET_VARIABLE.
+    * If NULL, obtains the complete environment string if more
+    * complex parsing is necessary.
+    * The environment string is formatted as key-value pairs
+    * delimited by semicolons as so:
+    * "key1=value1;key2=value2;..."
+    */
+   const char *key;
+
+   /* Value to be obtained. If key does not exist, it is set to NULL. */
+   const char *value;
+};
+
+struct retro_core_option_display
+{
+   /* Variable to configure in RETRO_ENVIRONMENT_SET_CORE_OPTIONS_DISPLAY */
+   const char *key;
+
+   /* Specifies whether variable should be displayed
+    * when presenting core options to the user */
+   bool visible;
+};
+
+/* Maximum number of values permitted for a core option
+ * > Note: We have to set a maximum value due the limitations
+ *   of the C language - i.e. it is not possible to create an
+ *   array of structs each containing a variable sized array,
+ *   so the retro_core_option_definition values array must
+ *   have a fixed size. The size limit of 128 is a balancing
+ *   act - it needs to be large enough to support all 'sane'
+ *   core options, but setting it too large may impact low memory
+ *   platforms. In practise, if a core option has more than
+ *   128 values then the implementation is likely flawed.
+ *   To quote the above API reference:
+ *      "The number of possible options should be very limited
+ *       i.e. it should be feasible to cycle through options
+ *       without a keyboard."
+ */
+#define RETRO_NUM_CORE_OPTION_VALUES_MAX 128
+
+struct retro_core_option_value
+{
+   /* Expected option value */
+   const char *value;
+
+   /* Human-readable value label. If NULL, value itself
+    * will be displayed by the frontend */
+   const char *label;
+};
+
+struct retro_core_option_definition
+{
+   /* Variable to query in RETRO_ENVIRONMENT_GET_VARIABLE. */
+   const char *key;
+
+   /* Human-readable core option description (used as menu label) */
+   const char *desc;
+
+   /* Human-readable core option information (used as menu sublabel) */
+   const char *info;
+
+   /* Array of retro_core_option_value structs, terminated by NULL */
+   struct retro_core_option_value values[RETRO_NUM_CORE_OPTION_VALUES_MAX];
+
+   /* Default core option value. Must match one of the values
+    * in the retro_core_option_value array, otherwise will be
+    * ignored */
+   const char *default_value;
+};
+
+struct retro_core_options_intl
+{
+   /* Pointer to an array of retro_core_option_definition structs
+    * - US English implementation
+    * - Must point to a valid array */
+   struct retro_core_option_definition *us;
+
+   /* Pointer to an array of retro_core_option_definition structs
+    * - Implementation for current frontend language
+    * - May be NULL */
+   struct retro_core_option_definition *local;
+};
+
+struct retro_game_info
+{
+   const char *path;       /* Path to game, UTF-8 encoded.
+                            * Sometimes used as a reference for building other paths.
+                            * May be NULL if game was loaded from stdin or similar,
+                            * but in this case some cores will be unable to load `data`.
+                            * So, it is preferable to fabricate something here instead
+                            * of passing NULL, which will help more cores to succeed.
+                            * retro_system_info::need_fullpath requires
+                            * that this path is valid. */
+   const void *data;       /* Memory buffer of loaded game. Will be NULL
+                            * if need_fullpath was set. */
+   size_t      size;       /* Size of memory buffer. */
+   const char *meta;       /* String of implementation specific meta-data. */
+};
+
+#define RETRO_MEMORY_ACCESS_WRITE (1 << 0)
+   /* The core will write to the buffer provided by retro_framebuffer::data. */
+#define RETRO_MEMORY_ACCESS_READ (1 << 1)
+   /* The core will read from retro_framebuffer::data. */
+#define RETRO_MEMORY_TYPE_CACHED (1 << 0)
+   /* The memory in data is cached.
+    * If not cached, random writes and/or reading from the buffer is expected to be very slow. */
+struct retro_framebuffer
+{
+   void *data;                      /* The framebuffer which the core can render into.
+                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER.
+                                       The initial contents of data are unspecified. */
+   unsigned width;                  /* The framebuffer width used by the core. Set by core. */
+   unsigned height;                 /* The framebuffer height used by the core. Set by core. */
+   size_t pitch;                    /* The number of bytes between the beginning of a scanline,
+                                       and beginning of the next scanline.
+                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER. */
+   enum retro_pixel_format format;  /* The pixel format the core must use to render into data.
+                                       This format could differ from the format used in
+                                       SET_PIXEL_FORMAT.
+                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER. */
+
+   unsigned access_flags;           /* How the core will access the memory in the framebuffer.
+                                       RETRO_MEMORY_ACCESS_* flags.
+                                       Set by core. */
+   unsigned memory_flags;           /* Flags telling core how the memory has been mapped.
+                                       RETRO_MEMORY_TYPE_* flags.
+                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER. */
+};
+
+/* Used by a libretro core to override the current
+ * fastforwarding mode of the frontend */
+struct retro_fastforwarding_override
+{
+   /* Specifies the runtime speed multiplier that
+    * will be applied when 'fastforward' is true.
+    * For example, a value of 5.0 when running 60 FPS
+    * content will cap the fast-forward rate at 300 FPS.
+    * Note that the target multiplier may not be achieved
+    * if the host hardware has insufficient processing
+    * power.
+    * Setting a value of 0.0 (or greater than 0.0 but
+    * less than 1.0) will result in an uncapped
+    * fast-forward rate (limited only by hardware
+    * capacity).
+    * If the value is negative, it will be ignored
+    * (i.e. the frontend will use a runtime speed
+    * multiplier of its own choosing) */
+   float ratio;
+
+   /* If true, fastforwarding mode will be enabled.
+    * If false, fastforwarding mode will be disabled. */
+   bool fastforward;
+
+   /* If true, and if supported by the frontend, an
+    * on-screen notification will be displayed while
+    * 'fastforward' is true.
+    * If false, and if supported by the frontend, any
+    * on-screen fast-forward notifications will be
+    * suppressed */
+   bool notification;
+
+   /* If true, the core will have sole control over
+    * when fastforwarding mode is enabled/disabled;
+    * the frontend will not be able to change the
+    * state set by 'fastforward' until either
+    * 'inhibit_toggle' is set to false, or the core
+    * is unloaded */
+   bool inhibit_toggle;
+};
+
+/* Callbacks */
+
+/* Environment callback. Gives implementations a way of performing
+ * uncommon tasks. Extensible. */
+typedef bool (RETRO_CALLCONV *retro_environment_t)(unsigned cmd, void *data);
+
+/* Render a frame. Pixel format is 15-bit 0RGB1555 native endian
+ * unless changed (see RETRO_ENVIRONMENT_SET_PIXEL_FORMAT).
+ *
+ * Width and height specify dimensions of buffer.
+ * Pitch specifices length in bytes between two lines in buffer.
+ *
+ * For performance reasons, it is highly recommended to have a frame
+ * that is packed in memory, i.e. pitch == width * byte_per_pixel.
+ * Certain graphic APIs, such as OpenGL ES, do not like textures
+ * that are not packed in memory.
+ */
+typedef void (RETRO_CALLCONV *retro_video_refresh_t)(const void *data, unsigned width,
+      unsigned height, size_t pitch);
+
+/* Renders a single audio frame. Should only be used if implementation
+ * generates a single sample at a time.
+ * Format is signed 16-bit native endian.
+ */
+typedef void (RETRO_CALLCONV *retro_audio_sample_t)(int16_t left, int16_t right);
+
+/* Renders multiple audio frames in one go.
+ *
+ * One frame is defined as a sample of left and right channels, interleaved.
+ * I.e. int16_t buf[4] = { l, r, l, r }; would be 2 frames.
+ * Only one of the audio callbacks must ever be used.
+ */
+typedef size_t (RETRO_CALLCONV *retro_audio_sample_batch_t)(const int16_t *data,
+      size_t frames);
+
+/* Polls input. */
+typedef void (RETRO_CALLCONV *retro_input_poll_t)(void);
+
+/* Queries for input for player 'port'. device will be masked with
+ * RETRO_DEVICE_MASK.
+ *
+ * Specialization of devices such as RETRO_DEVICE_JOYPAD_MULTITAP that
+ * have been set with retro_set_controller_port_device()
+ * will still use the higher level RETRO_DEVICE_JOYPAD to request input.
+ */
+typedef int16_t (RETRO_CALLCONV *retro_input_state_t)(unsigned port, unsigned device,
+      unsigned index, unsigned id);
+
+/* Sets callbacks. retro_set_environment() is guaranteed to be called
+ * before retro_init().
+ *
+ * The rest of the set_* functions are guaranteed to have been called
+ * before the first call to retro_run() is made. */
+RETRO_API void retro_set_environment(retro_environment_t);
+RETRO_API void retro_set_video_refresh(retro_video_refresh_t);
+RETRO_API void retro_set_audio_sample(retro_audio_sample_t);
+RETRO_API void retro_set_audio_sample_batch(retro_audio_sample_batch_t);
+RETRO_API void retro_set_input_poll(retro_input_poll_t);
+RETRO_API void retro_set_input_state(retro_input_state_t);
+
+/* Library global initialization/deinitialization. */
+RETRO_API void retro_init(void);
+RETRO_API void retro_deinit(void);
+
+/* Must return RETRO_API_VERSION. Used to validate ABI compatibility
+ * when the API is revised. */
+RETRO_API unsigned retro_api_version(void);
+
+/* Gets statically known system info. Pointers provided in *info
+ * must be statically allocated.
+ * Can be called at any time, even before retro_init(). */
+RETRO_API void retro_get_system_info(struct retro_system_info *info);
+
+/* Gets information about system audio/video timings and geometry.
+ * Can be called only after retro_load_game() has successfully completed.
+ * NOTE: The implementation of this function might not initialize every
+ * variable if needed.
+ * E.g. geom.aspect_ratio might not be initialized if core doesn't
+ * desire a particular aspect ratio. */
+RETRO_API void retro_get_system_av_info(struct retro_system_av_info *info);
+
+/* Sets device to be used for player 'port'.
+ * By default, RETRO_DEVICE_JOYPAD is assumed to be plugged into all
+ * available ports.
+ * Setting a particular device type is not a guarantee that libretro cores
+ * will only poll input based on that particular device type. It is only a
+ * hint to the libretro core when a core cannot automatically detect the
+ * appropriate input device type on its own. It is also relevant when a
+ * core can change its behavior depending on device type.
+ *
+ * As part of the core's implementation of retro_set_controller_port_device,
+ * the core should call RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS to notify the
+ * frontend if the descriptions for any controls have changed as a
+ * result of changing the device type.
+ */
+RETRO_API void retro_set_controller_port_device(unsigned port, unsigned device);
+
+/* Resets the current game. */
+RETRO_API void retro_reset(void);
+
+/* Runs the game for one video frame.
+ * During retro_run(), input_poll callback must be called at least once.
+ *
+ * If a frame is not rendered for reasons where a game "dropped" a frame,
+ * this still counts as a frame, and retro_run() should explicitly dupe
+ * a frame if GET_CAN_DUPE returns true.
+ * In this case, the video callback can take a NULL argument for data.
+ */
+RETRO_API void retro_run(void);
+
+/* Returns the amount of data the implementation requires to serialize
+ * internal state (save states).
+ * Between calls to retro_load_game() and retro_unload_game(), the
+ * returned size is never allowed to be larger than a previous returned
+ * value, to ensure that the frontend can allocate a save state buffer once.
+ */
+RETRO_API size_t retro_serialize_size(void);
+
+/* Serializes internal state. If failed, or size is lower than
+ * retro_serialize_size(), it should return false, true otherwise. */
+RETRO_API bool retro_serialize(void *data, size_t size);
+RETRO_API bool retro_unserialize(const void *data, size_t size);
+
+RETRO_API void retro_cheat_reset(void);
+RETRO_API void retro_cheat_set(unsigned index, bool enabled, const char *code);
+
+/* Loads a game.
+ * Return true to indicate successful loading and false to indicate load failure.
+ */
+RETRO_API bool retro_load_game(const struct retro_game_info *game);
+
+/* Loads a "special" kind of game. Should not be used,
+ * except in extreme cases. */
+RETRO_API bool retro_load_game_special(
+  unsigned game_type,
+  const struct retro_game_info *info, size_t num_info
+);
+
+/* Unloads the currently loaded game. Called before retro_deinit(void). */
+RETRO_API void retro_unload_game(void);
+
+/* Gets region of game. */
+RETRO_API unsigned retro_get_region(void);
+
+/* Gets region of memory. */
+RETRO_API void *retro_get_memory_data(unsigned id);
+RETRO_API size_t retro_get_memory_size(unsigned id);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
--- /dev/null
+++ b/mem.c
@@ -1,0 +1,346 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "fns.h"
+#include "dat.h"
+
+#define sysfatal(fmt, ...){printf(fmt"\n", ##__VA_ARGS__); exit(EXIT_FAILURE);}
+
+uint16_t ram[32768], vram[32768];
+uint16_t cram[64], vsram[40];
+uint32_t cramc[64];
+uint8_t zram[8192];
+uint8_t reg[32];
+uint8_t ctl[15];
+
+uint8_t dma;
+uint8_t vdplatch;
+uint16_t vdpaddr, vdpdata;
+
+uint8_t yma1, yma2;
+
+uint8_t z80bus = 0;
+uint16_t z80bank;
+
+//#define vramdebug(a, s, a1, a2, a3) if((a & ~1) == 0xe7a0) printf(s, a1, a2, a3);
+#define vramdebug(a, s, a1, a2, a3)
+
+uint8_t
+regread(uint16_t a)
+{
+	uint16_t v;
+
+	switch(a | 1){
+	case 0x0001: return 0xa0;
+	case 0x0003: case 0x0005:
+		//v = ~(keys[a-3>>1]);
+		if((ctl[a-3>>1] & 0x40) == 0)
+			v >>= 8;
+		return ctl[a-3>>1] & 0xc0 | v & 0x3f;
+	case 0x0007:
+		return ctl[a-3>>1] & 0xc0 | 0x3f;
+	case 0x0009: case 0x000b: case 0x000d:
+		return ctl[a-3>>1];
+	case 0x1101:
+		return (~z80bus & BUSACK) >> 1;
+	}
+	sysfatal("read from 0xa1%.4ux (pc=%#.6ux)", a, curpc);
+	return 0;
+}
+
+void
+regwrite(uint16_t a, uint16_t v)
+{
+	switch(a | 1){
+	case 0x0003: case 0x0005: case 0x0007:
+	case 0x0009: case 0x000b: case 0x000d:
+		ctl[a-3>>1] = v;
+		return;
+	case 0x1101:
+		z80bus = z80bus & ~BUSREQ | v & BUSREQ;
+		return;
+	case 0x1201:
+		if((v & 1) == 0){
+			z80bus |= RESET;
+			z80bus &= ~BUSACK;
+		}else
+			z80bus &= ~RESET;
+		return;
+	case 0x30f1:
+		if((v & 1) != 0)
+			sramctl |= SRAMEN;
+		else
+			sramctl &= ~SRAMEN;
+		return;
+	case 0x30f3: case 0x30f5: case 0x30f7: case 0x30f9: case 0x30fb:
+		return;
+	}
+	sysfatal("write to 0xa1%.4x (pc=%#.6ux)", a, curpc);
+}
+
+void
+cramwrite(uint16_t a, uint16_t v)
+{
+	uint32_t w;
+
+	cram[a/2] = v;
+	w = v << 12 & 0xe00000 | v << 8 & 0xe000 | v << 4 & 0xe0;
+	cramc[a/2] = w;
+}
+
+uint16_t
+memread(uint32_t a)
+{
+	printf("memread %x\n", a);
+	uint16_t v;
+
+	switch(a >> 21 & 7){
+	case 0: case 1:
+		if((sramctl & SRAMEN) != 0 && a >= sram0 && a <= sram1)
+			switch(sramctl & ADDRMASK){
+			case ADDREVEN: return sram[(a - sram0) >> 1] << 8;
+			case ADDRODD: return sram[(a - sram0) >> 1];
+			case ADDRBOTH: return sram[a - sram0] << 8 | sram[a - sram0 + 1];
+			}
+		return prg[(a % nprg) / 2];
+	case 5:
+		switch(a >> 16 & 0xff){
+		case 0xa0:
+			if((z80bus & BUSACK) != 0)
+				v = z80read(a & 0x7fff);
+			else
+				v = 0;
+			return v << 8 | v;
+		case 0xa1:
+			v = regread(a);
+			return v << 8 | v;
+		}
+		goto invalid;
+	case 6:
+		if((a & 0xe700e0) != 0xc00000)
+			goto invalid;
+		switch(a & 30){
+		case 0: case 2:
+			// vdplatch &= 0x7f;
+			// switch(vdplatch & 0xf){
+			// case 0:
+			// 	v = vram[vdpaddr/2];
+			// 	vdpaddr += reg[AUTOINC];
+			// 	break;
+			// case 4:
+			// 	v = vdpaddr & 0x7f;
+			// 	if(v < 80)
+			// 		v = vsram[v / 2];
+			// 	else
+			// 		v = 0;
+			// 	vdpaddr = (vdpaddr + reg[AUTOINC]) & 0x7f;
+			// 	break;
+			// case 8:
+			// 	v = cram[(vdpaddr & 0x7f) / 2];
+			// 	vdpaddr = (vdpaddr + reg[AUTOINC]) & 0x7f;
+			// 	break;
+			// default: v = 0;
+			// }
+			// return v;
+			return 0;
+		case 4: case 6:
+			// vdplatch &= 0x7f;
+			// v = vdpstat;
+			// if(dma != 0 && dma != 2)
+			// 	v |= STATDMA;
+			// if(vdpx >= 0xe4 || vdpx < 0x08)
+			// 	v |= STATHBL;
+			// return v;
+			return 0;
+		case 8: case 10: case 12: case 14:
+			// if((reg[MODE4] & WIDE) != 0)
+			// 	v = vdpx - (vdpx >= 360 ? 406 : 0);
+			// else
+			// 	v = vdpx - (vdpx >= 296 ? 342 : 0);
+			// if(intla)
+			// 	return vdpy - (vdpy >= 234 ? 5 : 0) << 8 & 0xfe00 | frame << 8 | v >> 1 & 0xff;
+			// return vdpy - (vdpy >= 234 ? 5 : 0) << 8 | v >> 1 & 0xff;
+			return 0;
+		default:
+			goto invalid;
+		}
+	case 7: return ram[((uint16_t)a) / 2];
+	default:
+	invalid:
+		sysfatal("read from %#.6ux (pc=%#.6ux)", a, curpc);
+		return 0;
+	}
+}
+
+void
+memwrite(uint32_t a, uint16_t v, uint16_t m)
+{
+	uint16_t *p;
+	uint16_t w;
+
+	if(0 && (a & 0xe0fffe) == 0xe0df46)
+		printf("%x %x %x\n", curpc, v, m);
+	switch((a >> 21) & 7){
+	case 0: case 1:
+		if((sramctl & SRAMEN) != 0 && a >= sram0 && a <= sram1){
+			switch(sramctl & ADDRMASK){
+			case ADDREVEN: sram[(a - sram0) >> 1] = v >> 8; break;
+			case ADDRODD: sram[(a - sram0) >> 1] = v; break;
+			case ADDRBOTH:
+				if((m & 0xff00) == 0xff00)
+					sram[a - sram0] = v >> 8;
+				if((m & 0xff) == 0xff)
+					sram[a + 1 - sram0] = v;
+				break;
+			}
+			// if(saveclock == 0)
+			// 	saveclock = SAVEFREQ;
+			return;
+		}
+		goto invalid;
+	case 5:
+		switch(a >> 16 & 0xff){
+		case 0xa0:
+			if((z80bus & BUSACK) != 0)
+				z80write(a & 0xffff, v >> 8);
+			return;
+		case 0xa1:
+			regwrite(a, v >> 8);
+			return;
+		default:
+			goto invalid;
+		}
+	case 6:
+		if((a & 0xe700e0) != 0xc00000)
+			goto invalid;
+		switch(a & 30){
+		case 0: case 2:
+			if(dma == 2){
+				dma = 4;
+				vdpdata = v >> 8;
+				vramdebug(vdpaddr, "vdp fill write val %x (pc = %x) %d\n", v & 0xff, curpc, 0);
+				p = &vram[vdpaddr / 2];
+				if((vdpaddr & 1) == 0)
+					*p = *p & 0xff | v << 8;
+				else
+					*p = *p & 0xff00 | v & 0xff;
+				return;
+			}
+			vdplatch &= 0x7f;
+			switch(vdplatch & 0xf){
+			case 1:
+				if((vdpaddr & 1) != 0)
+					v = v << 8 | v >> 8;
+				p = &vram[vdpaddr / 2];
+				vramdebug(vdpaddr, "vdp write val %x mask %x (pc = %x)\n", v, m, curpc);
+				*p = *p & ~m | v & m;
+				vdpaddr += reg[AUTOINC];
+				return;
+			case 3:
+				cramwrite(vdpaddr & 0x7f, v);
+				vdpaddr = (vdpaddr + reg[AUTOINC]) & 0x7f;
+				return;
+			case 5:
+				w = vdpaddr & 0x7f;
+				if(w < 80)
+					vsram[w / 2] = v;
+				vdpaddr = (vdpaddr + reg[AUTOINC]) & 0x7f;
+				return;
+			default:
+				return;
+			}
+		case 4: case 6:
+			//vdpwrite(v);
+			return;
+		case 16: case 18: case 20: case 22:
+			return;
+		default:
+			goto invalid;
+		}
+	case 7:
+		p = &ram[((uint16_t)a) / 2];
+		*p = *p & ~m | v & m;
+		break;
+	default:
+	invalid:
+		sysfatal("write to %#.6x (pc=%#.6x)", a, curpc);
+	}
+}
+
+extern uint8_t header[0x7fff];
+
+uint8_t
+z80read(uint16_t a)
+{
+	printf("z80read %x\n", a);
+	uint16_t v;
+
+	/*switch(a >> 13){
+	case 0:
+	case 1:
+		return zram[a & 0x1fff];
+		return 0;
+	case 2:
+		//return ymstat;
+		return 0;
+	case 3:
+		if(a >= 0x7f00){
+			v = memread(0xc00000 | a & 0x7e);
+			if((a & 1) == 0)
+				v >>= 8;
+			return v;
+		}
+		sysfatal("z80 read from %#.4x (pc=%#.4x)", a, scurpc);
+	default:
+		v = memread(z80bank << 15 | a & 0x7ffe);
+		if((a & 1) == 0)
+			v >>= 8;
+		return v;
+	}*/
+
+	if (a < 0x400)
+		return header[a];
+	else
+		printf("z80read > 0x400 %x\n", a);
+}
+
+void
+z80write(uint16_t a, uint8_t v)
+{
+	switch(a >> 13){
+	case 0:
+	case 1:
+		zram[a & 0x1fff] = v;
+		return;
+	case 2:
+		switch(a & 3){
+		case 0: yma1 = v; return;
+		case 1: ymwrite(yma1, v, 0); return;
+		case 2: yma2 = v; return;
+		case 3: ymwrite(yma2, v, 3); return;
+		}
+	case 3:
+		if(a < 0x6100){
+			z80bank = z80bank >> 1 | v << 8 & 0x100;
+			return;
+		}
+		if(a >= 0x7f00){
+			memwrite(0xc00000 | a & 0x7e, v | v << 8, (a & 1) != 0 ? 0xff : 0xff00);
+			return;
+		}
+		sysfatal("z80 write to %#.4x (pc=%#.4x)", a, scurpc);
+	default:
+		memwrite(z80bank << 15 | a & 0x7ffe, v << 8 | v, (a & 1) != 0 ? 0xff : 0xff00);
+	}
+}
+
+uint8_t
+z80in(uint8_t a)
+{
+	return 0xff;
+}
+
+void
+z80out(uint8_t a, uint8_t b)
+{
+}
--- /dev/null
+++ b/sms.c
@@ -1,0 +1,170 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "libretro.h"
+#include "dat.h"
+#include "fns.h"
+
+static retro_input_state_t input_state_cb;
+static retro_input_poll_t input_poll_cb;
+static retro_video_refresh_t video_cb;
+static retro_environment_t environ_cb;
+retro_audio_sample_batch_t audio_cb;
+
+uint32_t r[16], pc, curpc;
+extern uint16_t spc, scurpc, sp;
+uint32_t asp, irq, stop;
+int nprg;
+uint8_t *sram;
+uint32_t sramctl, nsram, sram0, sram1;
+int doflush = 0;
+uint8_t header[0x7fff];
+uint8_t *prg = NULL;
+uint32_t pic[256*224] = {0};
+
+void
+loadrom(const uint8_t *data)
+{
+	memcpy(header, data, sizeof(header));
+	prg = malloc(49152);
+	memcpy(prg, data+sizeof(header), 49152);
+	spc = 0;
+}
+
+void
+retro_init(void)
+{
+}
+
+void
+retro_get_system_info(struct retro_system_info *info)
+{
+	memset(info, 0, sizeof(*info));
+	info->library_name = "sms";
+	info->library_version = "1.0";
+	info->need_fullpath = false;
+	info->valid_extensions = "sms";
+}
+
+void
+retro_get_system_av_info(struct retro_system_av_info *info)
+{
+	info->timing.fps = 60.0;
+	info->timing.sample_rate = 48000;
+
+	info->geometry.base_width = 256;
+	info->geometry.base_height = 224;
+	info->geometry.max_width = 256;
+	info->geometry.max_height = 224;
+	info->geometry.aspect_ratio = 4.0 / 3.0;
+}
+
+unsigned
+retro_api_version(void)
+{
+	return RETRO_API_VERSION;
+}
+
+bool
+retro_load_game(const struct retro_game_info *game)
+{
+	printf("Loading game\n");
+	enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_XRGB8888;
+	if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt))
+		return false;
+
+	loadrom(game->data);
+	return true;
+}
+
+void
+process_inputs()
+{
+}
+
+void
+retro_run(void)
+{
+	input_poll_cb();
+	process_inputs();
+
+	while(!doflush){
+		z80step();
+	}
+	video_cb(pic, 256, 224, 256*4);
+	//audioout();
+	doflush = 0;
+}
+
+void
+flush(void)
+{
+	doflush = 1;
+}
+
+void
+retro_set_input_poll(retro_input_poll_t cb)
+{
+	input_poll_cb = cb;
+}
+
+void
+retro_set_input_state(retro_input_state_t cb)
+{
+	input_state_cb = cb;
+}
+
+void
+retro_set_video_refresh(retro_video_refresh_t cb)
+{
+	video_cb = cb;
+}
+
+void
+retro_set_environment(retro_environment_t cb)
+{
+	environ_cb = cb;
+}
+
+void
+retro_set_audio_sample_batch(retro_audio_sample_batch_t cb)
+{
+    audio_cb = cb;
+}
+
+void
+retro_reset(void)
+{
+	doflush = 0;
+}
+
+size_t
+retro_serialize_size(void)
+{
+	return 0;
+}
+
+bool
+retro_serialize(void *data, size_t size)
+{
+	return false;
+}
+
+bool
+retro_unserialize(const void *data, size_t size)
+{
+	return false;
+}
+
+void retro_set_controller_port_device(unsigned port, unsigned device) {}
+size_t retro_get_memory_size(unsigned id) { return 0; }
+void * retro_get_memory_data(unsigned id) { return NULL; }
+void retro_unload_game(void) {}
+void retro_deinit(void) {}
+void retro_set_audio_sample(retro_audio_sample_t cb) {}
+void retro_cheat_reset(void) {}
+void retro_cheat_set(unsigned index, bool enabled, const char *code) {}
+bool retro_load_game_special(unsigned game_type, const struct retro_game_info *info, size_t num_info) { return false; }
+unsigned retro_get_region(void) { return 0; }
+
--- /dev/null
+++ b/z80.c
@@ -1,0 +1,835 @@
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "fns.h"
+#include "dat.h"
+
+#define sysfatal(fmt, ...){printf(fmt"\n", ##__VA_ARGS__); exit(EXIT_FAILURE);}
+
+uint8_t s[16], ipage, intm, z80irq;
+uint16_t ix[2];
+uint16_t spc, scurpc, sp;
+int halt;
+
+enum {
+	FLAGC = 0x01,
+	FLAGN = 0x02,
+	FLAGV = 0x04,
+	FLAGH = 0x10,
+	FLAGZ = 0x40,
+	FLAGS = 0x80
+};
+enum { rB, rC, rD, rE, rH, rL, rHL, rA, rF = rHL };
+#define BC() (s[rB] << 8 | s[rC])
+#define DE() (s[rD] << 8 | s[rE])
+#define HL() (s[rH] << 8 | s[rL])
+
+static uint8_t
+fetch8(void)
+{
+	return z80read(spc++);
+}
+
+static uint16_t
+fetch16(void)
+{
+	uint16_t u;
+	
+	u = z80read(spc++);
+	return u | z80read(spc++) << 8;
+}
+
+static void
+push8(uint8_t u)
+{
+	z80write(--sp, u);
+}
+
+static void
+push16(uint16_t u)
+{
+	z80write(--sp, u >> 8);
+	z80write(--sp, u);
+}
+
+static uint8_t
+pop8(void)
+{
+	return z80read(sp++);
+}
+
+static uint16_t
+pop16(void)
+{
+	uint16_t v;
+	
+	v = z80read(sp++);
+	return v | z80read(sp++) << 8;
+}
+
+static uint16_t
+read16(uint16_t n)
+{
+	return z80read(n) | z80read(n+1) << 8;
+}
+
+static void
+write16(uint16_t n, uint16_t v)
+{
+	z80write(n++, v);
+	z80write(n, v >> 8);
+}
+
+static int
+parity(uint8_t v)
+{
+	return (((v * 0x0101010101010101ULL) & 0x8040201008040201ULL) % 0x1FF) & 1;
+}
+
+static int
+move(uint8_t dst, uint8_t src)
+{
+	if(dst == rHL){
+		if(src == rHL){
+			halt = 1;
+			return 4;
+		}
+		z80write(HL(), s[src]);
+		return 7;
+	}
+	if(src == rHL){
+		s[dst] = z80read(HL());
+		return 7;
+	}
+	s[dst] = s[src];
+	return 4;
+}
+
+static int
+alu(uint8_t op, uint8_t n)
+{
+	uint8_t v4;
+	uint8_t u;
+	uint16_t v;
+	int t;
+
+	switch(n){
+	case 8: u = fetch8(); t = 3; break;
+	case 10: u = ix[0]; t = 4; break;
+	case 11: u = ix[1]; t = 4; break;
+	case 12: u = ix[0] >> 8; t = 4; break;
+	case 13: u = ix[1] >> 8; t = 4; break;
+	case 14: u = z80read(ix[0] + fetch8()); t = 15; break;
+	case 15: u = z80read(ix[1] + fetch8()); t = 15; break;
+	case rHL:
+		u = z80read(HL());
+		t = 3;
+		break;
+	default:
+		u = s[n];
+		t = 0;
+	}
+	v4 = 0;
+	switch(op){
+	default:
+		v4 = (s[rA] & 0x0f) + (u & 0x0f);
+		v = s[rA] + u;
+		break;
+	case 1:
+		v4 = (s[rA] & 0x0f) + (u & 0x0f) + (s[rF] & 1);
+		v = s[rA] + u + (s[rF] & 1);
+		break;
+	case 2:
+	case 7:
+		v4 = (s[rA] & 0x0f) + (~u & 0x0f) + 1;
+		v = s[rA] + (u ^ 0xff) + 1;
+		break;
+	case 3:
+		v4 = (s[rA] & 0x0f) + (~u & 0x0f) + (~s[rF] & 1);
+		v = s[rA] + (u ^ 0xff) + (~s[rF] & 1);
+		break;
+	case 4: v = s[rA] & u; break;
+	case 5: v = s[rA] ^ u; break;
+	case 6: v = s[rA] | u; break;
+	}
+	s[rF] = 0;
+	if((uint8_t)v == 0)
+		s[rF] |= FLAGZ;
+	if((v & 0x80) != 0)
+		s[rF] |= FLAGS;
+	if(op < 2){
+		if((v & 0x100) != 0)
+			s[rF] |= FLAGC;
+		if((v4 & 0x10) != 0)
+			s[rF] |= FLAGH;
+		if((~(s[rA] ^ u) & (s[rA] ^ v) & 0x80) != 0)
+			s[rF] |= FLAGV;
+	}else if(op < 4 || op == 7){
+		s[rF] |= FLAGN;
+		if((v & 0x100) == 0)
+			s[rF] |= FLAGC;
+		if((v4 & 0x10) == 0)
+			s[rF] |= FLAGH;
+		if(((s[rA] ^ u) & (s[rA] ^ v) & 0x80) != 0)
+			s[rF] |= FLAGV;
+	}else{
+		if(!parity(v))
+			s[rF] |= FLAGV;
+		if(op == 4)
+			s[rF] |= FLAGH;
+	}
+	if(op != 7)
+		s[rA] = v;
+	return 4+t;
+}
+
+static int
+branch(int cc, int t)
+{
+	uint16_t v;
+	
+	v = (int8_t)fetch8();
+	if(!cc)
+		return t + 7;
+	spc += v;
+	return t + 12;
+}
+
+static uint8_t
+inc(uint8_t v)
+{
+	s[rF] &= FLAGC;
+	++v;
+	if(v == 0)
+		s[rF] |= FLAGZ;
+	if((v & 0x80) != 0)
+		s[rF] |= FLAGS;
+	if(v == 0x80)
+		s[rF] |= FLAGV;
+	if((v & 0xf) == 0)
+		s[rF] |= FLAGH;
+	return v;
+}
+
+static uint8_t
+dec(uint8_t v)
+{
+	--v;
+	s[rF] = s[rF] & FLAGC | FLAGN;
+	if(v == 0)
+		s[rF] |= FLAGZ;
+	if((v & 0x80) != 0)
+		s[rF] |= FLAGS;
+	if(v == 0x7f)
+		s[rF] |= FLAGV;
+	if((v & 0xf) == 0xf)
+		s[rF] |= FLAGH;
+	return v;
+}
+
+static int
+addhl(uint16_t u)
+{
+	uint32_t v;
+	
+	s[rF] &= ~(FLAGN|FLAGC|FLAGH);
+	v = HL() + u;
+	if((v & 0x10000) != 0)
+		s[rF] |= FLAGC;
+	if((HL() & 0xfff) + (u & 0xfff) >= 0x1000)
+		s[rF] |= FLAGH;
+	s[rL] = v;
+	s[rH] = v >> 8;
+	return 11;
+}
+
+static void
+adchl(uint16_t u)
+{
+	uint32_t v, v4;
+	
+	v = HL() + u + (s[rF] & FLAGC);
+	v4 = (HL() & 0xfff) + (u & 0xfff) + (s[rF] & FLAGC);
+	s[rF] = 0;
+	if((v & 0x10000) != 0)
+		s[rF] |= FLAGC;
+	if((v4 & 0x1000) != 0)
+		s[rF] |= FLAGH;
+	if((uint16_t)v == 0)
+		s[rF] |= FLAGZ;
+	if((v & 0x8000) != 0)
+		s[rF] |= FLAGS;
+	if((~(HL() ^ u) & (HL() ^ v) & 0x8000) != 0)
+		s[rF] |= FLAGV;
+	s[rL] = v;
+	s[rH] = v >> 8;
+}
+
+static void
+sbchl(uint16_t u)
+{
+	uint32_t v, v4;
+	
+	v = HL() + (uint16_t)~u + (~s[rF] & FLAGC);
+	v4 = (HL() & 0xfff) + (~u & 0xfff) + (~s[rF] & FLAGC);
+	s[rF] = FLAGN;
+	if((v & 0x10000) == 0)
+		s[rF] |= FLAGC;
+	if((v4 & 0x1000) == 0)
+		s[rF] |= FLAGH;
+	if((uint16_t)v == 0)
+		s[rF] |= FLAGZ;
+	if((v & 0x8000) != 0)
+		s[rF] |= FLAGS;
+	if(((HL() ^ u) & (HL() ^ v) & 0x8000) != 0)
+		s[rF] |= FLAGV;
+	s[rL] = v;
+	s[rH] = v >> 8;
+}
+
+static int
+addindex(int n, uint16_t u)
+{
+	uint32_t v;
+	
+	s[rF] &= ~(FLAGN|FLAGC|FLAGH);
+	v = ix[n] + u;
+	if((v & 0x10000) != 0)
+		s[rF] |= FLAGC;
+	if((ix[n] & 0xfff) + (u & 0xfff) >= 0x1000)
+		s[rF] |= FLAGH;
+	ix[n] = v;
+	return 15;
+}
+
+static int
+jump(int cc)
+{
+	uint16_t v;
+	
+	v = fetch16();
+	if(cc)
+		spc = v;
+	return 10;
+}
+
+static int
+call(uint16_t a, int cc)
+{
+	if(!cc)
+		return 10;
+	push16(spc);
+	spc = a;
+	return 17;
+}
+
+static void
+swap(uint8_t a)
+{
+	uint8_t v;
+	
+	v = s[a];
+	s[a] = s[a + 8];
+	s[a + 8] = v;
+}
+
+static int
+bits(int i)
+{
+	uint8_t op, v, n, m, c;
+	uint16_t a;
+	int t;
+	
+	//SET(a, v, t);
+	a = 0;
+	v = 0;
+	t = 0;
+	if(i >= 0){
+		a = ix[i] + fetch8();
+		v = z80read(a);
+		t = 23;
+	}
+	op = fetch8();
+	n = op & 7;
+	m = op >> 3 & 7;
+	if(i < 0){
+		a = HL();
+		if(n == 6){
+			v = z80read(a);
+			t = 15;
+		}else{
+			v = s[n];
+			t = 8;
+		}
+	}
+	switch(op >> 6){
+	case 0:
+		c = s[rF] & FLAGC;
+		switch(m){
+		default: s[rF] = v >> 7; v = v << 1 | v >> 7; break;
+		case 1:  s[rF] = v & 1; v = v >> 1 | v << 7; break;
+		case 2:  s[rF] = v >> 7; v = v << 1 | c; break;
+		case 3:  s[rF] = v & 1; v = v >> 1 | c << 7; break;
+		case 4:  s[rF] = v >> 7; v = v << 1; break;
+		case 5:  s[rF] = v & 1; v = v & 0x80 | v >> 1; break;
+		case 6:  s[rF] = v >> 7; v = v << 1 | 1; break;
+		case 7:  s[rF] = v & 1; v >>= 1; break;
+		}
+		if(v == 0)
+			s[rF] |= FLAGZ;
+		if((v & 0x80) != 0)
+			s[rF] |= FLAGS;
+		if(!parity(v))
+			s[rF] |= FLAGV;
+		break;
+	case 1:
+		s[rF] = s[rF] & ~(FLAGN|FLAGZ) | FLAGH;
+		if((v & 1<<m) == 0)
+			s[rF] |= FLAGZ;
+		return t;
+	case 2:
+		v &= ~(1<<m);
+		break;
+	case 3:
+		v |= (1<<m);
+	}
+	if(n == 6)
+		z80write(a, v);
+	else
+		s[n] = v;
+	return t;
+}
+
+static int
+ed(void)
+{
+	uint8_t op, v, u, l;
+	uint16_t a;
+	
+	op = fetch8();
+	switch(op){
+	case 0xa0: case 0xa1: case 0xa8: case 0xa9:
+	case 0xb0: case 0xb1: case 0xb8: case 0xb9:
+		switch(op & 3){
+		default:
+			z80write(DE(), z80read(HL()));
+			s[rF] &= ~(FLAGN|FLAGH);
+			l = 1;
+			break;
+		case 1:
+			u = z80read(HL());
+			v = s[rA] - u;
+			s[rF] = s[rF] & ~(FLAGS|FLAGZ|FLAGH) | FLAGN;
+			l = v != 0;
+			if((v & 0x80) != 0)
+				s[rF] |= FLAGS;
+			if(v == 0)
+				s[rF] |= FLAGZ;
+			if((s[rA] & 0xf) < (u & 0xf))
+				s[rF] |= FLAGH;
+			break;
+		}
+		if((op & 8) != 0){
+			if((op & 3) == 0 && s[rE]-- == 0)
+				s[rD]--;
+			if(s[rL]-- == 0)
+				s[rH]--;
+		}else{
+			if((op & 3) == 0 && ++s[rE] == 0)
+				s[rD]++;
+			if(++s[rL] == 0)
+				s[rH]++;
+		}
+		if(s[rC]-- == 0)
+			s[rB]--;
+		if((s[rC] | s[rB]) != 0){
+			s[rF] |= FLAGV;
+			if((op & 0x10) != 0 && l){
+				spc -= 2;
+				return 21;
+			}
+		}else
+			s[rF] &= ~FLAGV;
+		return 16;
+	case 0x42: sbchl(BC()); return 15;
+	case 0x52: sbchl(DE()); return 15;
+	case 0x62: sbchl(HL()); return 15;
+	case 0x72: sbchl(sp); return 15;
+	case 0x43: write16(fetch16(), BC()); return 20;
+	case 0x53: write16(fetch16(), DE()); return 20;
+	case 0x63: write16(fetch16(), HL()); return 20;
+	case 0x73: write16(fetch16(), sp); return 20;
+	case 0x44:
+		s[rA] = -s[rA];
+		s[rF] = FLAGN;
+		if(s[rA] == 0)
+			s[rF] |= FLAGZ;
+		else
+			s[rF] |= FLAGC;
+		if((s[rA] & 0x80) != 0)
+			s[rF] |= FLAGS;
+		if(s[rA] == 0x80)
+			s[rF] |= FLAGV;
+		if((s[rA] & 0xf) != 0)
+			s[rF] |= FLAGH;
+		return 8;
+	case 0x46: intm &= 0xc0; return 8;
+	case 0x56: intm = intm & 0xc0 | 1; return 8;
+	case 0x47: ipage = s[rA]; return 9;
+	case 0x57: s[rA] = ipage; return 9;
+	case 0x67:
+		v = z80read(HL());
+		z80write(HL(), v >> 4 | s[rA] << 4);
+		s[rA] = s[rA] & 0xf0 | v & 0x0f;
+		if(0){
+	case 0x6f:
+			v = z80read(HL());
+			z80write(HL(), v << 4 | s[rA] & 0xf);
+			s[rA] = s[rA] & 0xf0 | v >> 4;
+		}
+		s[rF] &= FLAGC;
+		if(s[rA] == 0)
+			s[rF] |= FLAGZ;
+		if((s[rA] & 0x80) != 0)
+			s[rF] |= FLAGS;
+		if(!parity(s[rA]))
+			s[rF] |= FLAGV;
+		return 18;
+	case 0x4a: adchl(BC()); return 15;
+	case 0x5a: adchl(DE()); return 15;
+	case 0x6a: adchl(HL()); return 15;
+	case 0x7a: adchl(sp); return 15;
+	case 0x4b: a = fetch16(); s[rC] = z80read(a++); s[rB] = z80read(a); return 20;
+	case 0x5b: a = fetch16(); s[rE] = z80read(a++); s[rD] = z80read(a); return 20;
+	case 0x6b: a = fetch16(); s[rL] = z80read(a++); s[rH] = z80read(a); return 20;
+	case 0x7b: sp = read16(fetch16()); return 20;
+	case 0x4d: spc = pop16(); return 14;
+	case 0x5e: intm = intm & 0xc0 | 2; return 8;
+	case 0x4f: return 9;
+	case 0x78: printf("- ed78\n"); return 0;
+	case 0x61: printf("- ed61\n"); return 0;
+	case 0x69: printf("- ed69\n"); return 0;
+	}
+	sysfatal("undefined z80 opcode ed%.2x at pc=%#.4x", op, scurpc);
+	return 0;
+}
+
+static int
+index_(int n)
+{
+	uint8_t op;
+	uint16_t v;
+	
+	op = fetch8();
+	switch(op){
+	case 0x40: case 0x41: case 0x42: case 0x43: case 0x47:
+	case 0x48: case 0x49: case 0x4a: case 0x4b: case 0x4f:
+	case 0x50: case 0x51: case 0x52: case 0x53: case 0x57:
+	case 0x58: case 0x59: case 0x5a: case 0x5b: case 0x5f:
+	case 0x78: case 0x79: case 0x7a: case 0x7b: case 0x7f:
+		s[op >> 3 & 7] = s[op & 7];
+		return 8;
+	case 0x60: case 0x61: case 0x62: case 0x63: case 0x67:
+		ix[n] = ix[n] & 0xff | s[op & 7] << 8;
+		return 8;
+	case 0x68: case 0x69: case 0x6a: case 0x6b: case 0x6f:
+		ix[n] = ix[n] & 0xff00 | s[op & 7];
+		return 8;
+	case 0x65: ix[n] = ix[n] << 8 | ix[n] & 0xff; return 8;
+	case 0x6c: ix[n] = ix[n] >> 8 | ix[n] & 0xff00; return 8;
+	case 0x64: case 0x6d: return 8;
+	case 0x70: case 0x71: case 0x72: case 0x73:
+	case 0x74: case 0x75: case 0x77:
+		z80write(ix[n] + fetch8(), s[op & 7]);
+		return 19;
+	case 0x44: case 0x4c: case 0x54: case 0x5c: case 0x7c:
+		s[op >> 3 & 7] = ix[n] >> 8;
+		return 8;
+	case 0x45: case 0x4d: case 0x55: case 0x5d: case 0x7d:
+		s[op >> 3 & 7] = ix[n];
+		return 8;
+	case 0x46: case 0x4e: case 0x56: case 0x5e: case 0x66: case 0x6e: case 0x7e:
+		s[op >> 3 & 7] = z80read(ix[n] + fetch8());
+		return 19;
+	case 0x84: case 0x8c: case 0x94: case 0x9c:
+	case 0xa4: case 0xac: case 0xb4: case 0xbc:
+		return alu(op >> 3 & 7, 12 + n);
+	case 0x85: case 0x8d: case 0x95: case 0x9d:
+	case 0xa5: case 0xad: case 0xb5: case 0xbd:
+		return alu(op >> 3 & 7, 10 + n);
+	case 0x86: case 0x8e: case 0x96: case 0x9e:
+	case 0xa6: case 0xae: case 0xb6: case 0xbe:
+		return alu(op >> 3 & 7, 14 + n);	
+	
+	case 0x21: ix[n] = fetch16(); return 14;
+	case 0xe1: ix[n] = pop16(); return 14;
+	case 0x22: write16(fetch16(), ix[n]); return 20;
+	case 0x23: ix[n]++; return 10;
+	case 0xe3: v = ix[n]; ix[n] = read16(sp); write16(sp, v); return 23;
+	case 0x24: inc(ix[n] >> 8); ix[n] += 0x100; return 8;
+	case 0x34: v = ix[n] + fetch8(); z80write(v, inc(z80read(v))); return 23;
+	case 0x25: dec(ix[n] >> 8); ix[n] -= 0x100; return 8;
+	case 0x35: v = ix[n] + fetch8(); z80write(v, dec(z80read(v))); return 23;
+	case 0xe5: push16(ix[n]); return 15;
+	case 0x26: ix[n] = ix[n] & 0xff | fetch8() << 8; return 11;
+	case 0x36: v = ix[n] + fetch8(); z80write(v, fetch8()); return 19;
+	case 0x09: return addindex(n, BC());
+	case 0x19: return addindex(n, DE());
+	case 0x29: return addindex(n, ix[n]);
+	case 0x39: return addindex(n, sp);
+	case 0xe9: spc = ix[n]; return 8;
+	case 0xf9: sp = ix[n]; return 10;
+	case 0x2a: ix[n] = read16(fetch16()); return 20;
+	case 0x2b: ix[n]--; return 10;
+	case 0xcb: return bits(n);
+	case 0x2c: inc(ix[n]++); return 8;
+	case 0x2d: dec(ix[n]--); return 8;
+	case 0x2e: ix[n] = ix[n] & 0xff00 | fetch8(); return 11;
+	}
+	sysfatal("undefined z80 opcode %.2x%.2x at pc=%#.4x", n ? 0xfd : 0xdd, op, scurpc);
+	return 0;
+}
+
+int
+z80step(void)
+{
+	uint8_t op;
+	uint16_t v, w;
+
+	if((z80bus & RESET) != 0){
+		printf("reset\n");
+		scurpc = spc = 0;
+		intm = 0;
+		ipage = 0;
+		return 1;
+	}
+	if((z80bus & BUSACK) != 0){
+		printf("busack\n");
+		if((z80bus & BUSREQ) == 0)
+			z80bus &= ~BUSACK;
+		return 1;
+	}
+	if((z80bus & BUSREQ) != 0){
+		printf("busreq\n");
+		z80bus |= BUSACK;
+		return 1;
+	}
+	if(z80irq != 0 && (intm & 0x80) != 0){
+		printf("irq\n");
+		push16(spc);
+		intm &= 0x3f;
+		switch(intm & 3){
+		case 1:
+			spc = 0x38;
+			return 2;
+		default:
+			sysfatal("z80 interrupt in mode %d", intm & 3);
+		}
+	}
+	scurpc = spc;
+	if(1)
+		printf("%x AF %.2x%.2x BC %.2x%.2x DE %.2x%.2x HL %.2x%.2x IX %.4x IY %.4x\n", scurpc, s[rA], s[rF], s[rB], s[rC], s[rD], s[rE], s[rH], s[rL], ix[0], ix[1]);
+	op = fetch8();
+	printf("op: %x\n", op);
+	switch(op >> 6){
+	case 1: return move(op >> 3 & 7, op & 7);
+	case 2: return alu(op >> 3 & 7, op & 7);
+	}
+	switch(op){
+	case 0x00: return 4;
+	case 0x10: return branch(--s[rB] != 0, 1);
+	case 0x20: return branch((s[rF] & FLAGZ) == 0, 0);
+	case 0x30: return branch((s[rF] & FLAGC) == 0, 0);
+	case 0x01: s[rC] = fetch8(); s[rB] = fetch8(); return 10;
+	case 0x11: s[rE] = fetch8(); s[rD] = fetch8(); return 10;
+	case 0x21: s[rL] = fetch8(); s[rH] = fetch8(); return 10;
+	case 0x31: sp = fetch16(); return 10;
+	case 0x02: z80write(BC(), s[rA]); return 7;
+	case 0x12: z80write(DE(), s[rA]); return 7;
+	case 0x22: v = fetch16(); z80write(v++, s[rL]); z80write(v, s[rH]); return 16;
+	case 0x32: z80write(fetch16(), s[rA]); return 13;
+	case 0x03: if(++s[rC] == 0) s[rB]++; return 6;
+	case 0x13: if(++s[rE] == 0) s[rD]++; return 6;
+	case 0x23: if(++s[rL] == 0) s[rH]++; return 6;
+	case 0x33: sp++; return 6;
+	case 0x04: inc(s[rB]++); return 4;
+	case 0x14: inc(s[rD]++); return 4;
+	case 0x24: inc(s[rH]++); return 4;
+	case 0x34: z80write(HL(), inc(z80read(HL()))); return 11;
+	case 0x05: dec(s[rB]--); return 4;
+	case 0x15: dec(s[rD]--); return 4;
+	case 0x25: dec(s[rH]--); return 4;
+	case 0x35: z80write(HL(), dec(z80read(HL()))); return 11;
+	case 0x06: s[rB] = fetch8(); return 7;
+	case 0x16: s[rD] = fetch8(); return 7;
+	case 0x26: s[rH] = fetch8(); return 7;
+	case 0x36: z80write(HL(), fetch8()); return 10;
+	case 0x07:
+		s[rF] = s[rF] & ~(FLAGC|FLAGN|FLAGH) | s[rA] >> 7;
+		s[rA] = s[rA] << 1 | s[rA] >> 7;
+		return 4;
+	case 0x17:
+		v = s[rF] & FLAGC;
+		s[rF] = s[rF] & ~(FLAGC|FLAGN|FLAGH) | s[rA] >> 7;
+		s[rA] = s[rA] << 1 | v;
+		return 4;
+	case 0x27:
+		if(s[rA] > 0x99 || (s[rF] & FLAGC) != 0){
+			s[rF] |= FLAGC;
+			v = 0x60;
+		}else{
+			s[rF] &= ~FLAGC;
+			v = 0;
+		}
+		if((s[rA] & 0xf) > 9 || (s[rF] & FLAGH) != 0)
+			v |= 6;
+		w = s[rA];
+		if((s[rF] & FLAGN) != 0)
+			s[rA] -= v;
+		else
+			s[rA] += v;
+		s[rF] &= ~(FLAGV|FLAGS|FLAGZ|FLAGH);
+		if(((s[rA] ^ w) & 0x10) != 0)
+			s[rF] |= FLAGH;
+		if(!parity(s[rA]))
+			s[rF] |= FLAGV;
+		if(s[rA] == 0)
+			s[rF] |= FLAGZ;
+		if((s[rA] & 0x80) != 0)
+			s[rF] |= FLAGS;
+		return 4;
+	case 0x37: s[rF] = s[rF] & ~(FLAGN | FLAGH) | FLAGC; return 4;
+	case 0x08:
+		swap(rA);
+		swap(rF);
+		return 4;
+	case 0x18: return branch(1, 0);
+	case 0x28: return branch((s[rF] & FLAGZ) != 0, 0);
+	case 0x38: return branch((s[rF] & FLAGC) != 0, 0);
+	case 0x09: return addhl(BC());
+	case 0x19: return addhl(DE());
+	case 0x29: return addhl(HL());
+	case 0x39: return addhl(sp);
+	case 0x0a: s[rA] = z80read(BC()); return 7;
+	case 0x1a: s[rA] = z80read(DE()); return 7;
+	case 0x2a: v = fetch16(); s[rL] = z80read(v++); s[rH] = z80read(v); return 16;
+	case 0x3a: s[rA] = z80read(fetch16()); return 13;
+	case 0x0b: if(s[rC]-- == 0) s[rB]--; return 6;
+	case 0x1b: if(s[rE]-- == 0) s[rD]--; return 6;
+	case 0x2b: if(s[rL]-- == 0) s[rH]--; return 6;
+	case 0x3b: sp--; return 6;
+	case 0x0c: inc(s[rC]++); return 4;
+	case 0x1c: inc(s[rE]++); return 4;
+	case 0x2c: inc(s[rL]++); return 4;
+	case 0x3c: inc(s[rA]++); return 4;
+	case 0x0d: dec(s[rC]--); return 4;
+	case 0x1d: dec(s[rE]--); return 4;
+	case 0x2d: dec(s[rL]--); return 4;
+	case 0x3d: dec(s[rA]--); return 4;
+	case 0x0e: s[rC] = fetch8(); return 7;
+	case 0x1e: s[rE] = fetch8(); return 7;
+	case 0x2e: s[rL] = fetch8(); return 7;
+	case 0x3e: s[rA] = fetch8(); return 7;
+	case 0x0f:
+		s[rF] = s[rF] & ~(FLAGC|FLAGN|FLAGH) | s[rA] & 1;
+		s[rA] = s[rA] >> 1 | s[rA] << 7;
+		return 4;
+	case 0x1f:
+		v = s[rF] << 7;
+		s[rF] = s[rF] & ~(FLAGC|FLAGN|FLAGH) | s[rA] & 1;
+		s[rA] = s[rA] >> 1 | v;
+		return 4;
+	case 0x2f:
+		s[rF] |= FLAGN|FLAGH;
+		s[rA] ^= 0xff;
+		return 4;
+	case 0x3f:
+		s[rF] = s[rF] & ~(FLAGN|FLAGH) ^ FLAGC | s[rF] << 4 & FLAGH;
+		return 4;
+	case 0xc0: if((s[rF] & FLAGZ) == 0) {spc = pop16(); return 11;} return 5;
+	case 0xd0: if((s[rF] & FLAGC) == 0) {spc = pop16(); return 11;} return 5;
+	case 0xe0: if((s[rF] & FLAGV) == 0) {spc = pop16(); return 11;} return 5;
+	case 0xf0: if((s[rF] & FLAGS) == 0) {spc = pop16(); return 11;} return 5;
+	case 0xc1: s[rC] = pop8(); s[rB] = pop8(); return 10;
+	case 0xd1: s[rE] = pop8(); s[rD] = pop8(); return 10;
+	case 0xe1: s[rL] = pop8(); s[rH] = pop8(); return 10;
+	case 0xf1: s[rF] = pop8(); s[rA] = pop8(); return 10;
+	case 0xc2: return jump((s[rF] & FLAGZ) == 0);
+	case 0xd2: return jump((s[rF] & FLAGC) == 0);
+	case 0xe2: return jump((s[rF] & FLAGV) == 0);
+	case 0xf2: return jump((s[rF] & FLAGS) == 0);
+	case 0xc3: return jump(1);
+	case 0xd3: z80out(fetch8(), s[rA]); return 11;
+	case 0xe3:
+		v = HL();
+		s[rL] = z80read(sp);
+		s[rH] = z80read(sp + 1);
+		write16(sp, v);
+		return 19;
+	case 0xf3: intm &= 0x3f; return 4;
+	case 0xc4: return call(fetch16(), (s[rF] & FLAGZ) == 0);
+	case 0xd4: return call(fetch16(), (s[rF] & FLAGC) == 0);
+	case 0xe4: return call(fetch16(), (s[rF] & FLAGV) == 0);
+	case 0xf4: return call(fetch16(), (s[rF] & FLAGS) == 0);
+	case 0xc5: push8(s[rB]); push8(s[rC]); return 11;
+	case 0xd5: push8(s[rD]); push8(s[rE]); return 11;
+	case 0xe5: push8(s[rH]); push8(s[rL]); return 11;
+	case 0xf5: push8(s[rA]); push8(s[rF]); return 11;
+	case 0xc6: return alu(0, 8);
+	case 0xd6: return alu(2, 8);
+	case 0xe6: return alu(4, 8);
+	case 0xf6: return alu(6, 8);
+	case 0xc7: return call(0x00, 1);
+	case 0xd7: return call(0x10, 1);
+	case 0xe7: return call(0x20, 1);
+	case 0xf7: return call(0x30, 1);
+	case 0xc8: if((s[rF] & FLAGZ) != 0) {spc = pop16(); return 11;} return 5;
+	case 0xd8: if((s[rF] & FLAGC) != 0) {spc = pop16(); return 11;} return 5;
+	case 0xe8: if((s[rF] & FLAGV) != 0) {spc = pop16(); return 11;} return 5;
+	case 0xf8: if((s[rF] & FLAGS) != 0) {spc = pop16(); return 11;} return 5;
+	case 0xc9: spc = pop16(); return 10;
+	case 0xd9:
+		swap(rB);
+		swap(rC);
+		swap(rD);
+		swap(rE);
+		swap(rH);
+		swap(rL);
+		return 4;
+	case 0xe9: spc = HL(); return 4;
+	case 0xf9: sp = HL(); return 6;
+	case 0xca: return jump((s[rF] & FLAGZ) != 0);
+	case 0xda: return jump((s[rF] & FLAGC) != 0);
+	case 0xea: return jump((s[rF] & FLAGV) != 0);
+	case 0xfa: return jump((s[rF] & FLAGS) != 0);
+	case 0xcb: return bits(-1);
+	case 0xdb: s[rA] = z80in(fetch8()); return 11;
+	case 0xeb:
+		v = DE();
+		s[rD] = s[rH];
+		s[rE] = s[rL];
+		s[rH] = v >> 8;
+		s[rL] = v;
+		return 4;
+	case 0xfb: intm |= 0xc0; return 4;
+	case 0xcc: return call(fetch16(), (s[rF] & FLAGZ) != 0);
+	case 0xdc: return call(fetch16(), (s[rF] & FLAGC) != 0);
+	case 0xec: return call(fetch16(), (s[rF] & FLAGV) != 0);
+	case 0xfc: return call(fetch16(), (s[rF] & FLAGS) != 0);
+	case 0xcd: return call(fetch16(), 1);
+	case 0xdd: return index_(0);
+	case 0xed: return ed();
+	case 0xfd: return index_(1);
+	case 0xce: return alu(1, 8);
+	case 0xde: return alu(3, 8);
+	case 0xee: return alu(5, 8);
+	case 0xfe: return alu(7, 8);
+	case 0xcf: return call(0x08, 1);
+	case 0xdf: return call(0x18, 1);
+	case 0xef: return call(0x28, 1);
+	case 0xff: return call(0x38, 1);
+	}
+	sysfatal("undefined z80 opcode %#.2x at pc=%#.4x", op, scurpc);
+	return 0;
+}
--