snes9x/fxinst.h

/***********************************************************************************
  Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.

  (c) Copyright 1996 - 2002  Gary Henderson (gary.henderson@ntlworld.com),
                             Jerremy Koot (jkoot@snes9x.com)

  (c) Copyright 2002 - 2004  Matthew Kendora

  (c) Copyright 2002 - 2005  Peter Bortas (peter@bortas.org)

  (c) Copyright 2004 - 2005  Joel Yliluoma (http://iki.fi/bisqwit/)

  (c) Copyright 2001 - 2006  John Weidman (jweidman@slip.net)

  (c) Copyright 2002 - 2006  funkyass (funkyass@spam.shaw.ca),
                             Kris Bleakley (codeviolation@hotmail.com)

  (c) Copyright 2002 - 2010  Brad Jorsch (anomie@users.sourceforge.net),
                             Nach (n-a-c-h@users.sourceforge.net),

  (c) Copyright 2002 - 2011  zones (kasumitokoduck@yahoo.com)

  (c) Copyright 2006 - 2007  nitsuja

  (c) Copyright 2009 - 2018  BearOso,
                             OV2

  (c) Copyright 2017         qwertymodo

  (c) Copyright 2011 - 2017  Hans-Kristian Arntzen,
                             Daniel De Matteis
                             (Under no circumstances will commercial rights be given)


  BS-X C emulator code
  (c) Copyright 2005 - 2006  Dreamer Nom,
                             zones

  C4 x86 assembler and some C emulation code
  (c) Copyright 2000 - 2003  _Demo_ (_demo_@zsnes.com),
                             Nach,
                             zsKnight (zsknight@zsnes.com)

  C4 C++ code
  (c) Copyright 2003 - 2006  Brad Jorsch,
                             Nach

  DSP-1 emulator code
  (c) Copyright 1998 - 2006  _Demo_,
                             Andreas Naive (andreasnaive@gmail.com),
                             Gary Henderson,
                             Ivar (ivar@snes9x.com),
                             John Weidman,
                             Kris Bleakley,
                             Matthew Kendora,
                             Nach,
                             neviksti (neviksti@hotmail.com)

  DSP-2 emulator code
  (c) Copyright 2003         John Weidman,
                             Kris Bleakley,
                             Lord Nightmare (lord_nightmare@users.sourceforge.net),
                             Matthew Kendora,
                             neviksti

  DSP-3 emulator code
  (c) Copyright 2003 - 2006  John Weidman,
                             Kris Bleakley,
                             Lancer,
                             z80 gaiden

  DSP-4 emulator code
  (c) Copyright 2004 - 2006  Dreamer Nom,
                             John Weidman,
                             Kris Bleakley,
                             Nach,
                             z80 gaiden

  OBC1 emulator code
  (c) Copyright 2001 - 2004  zsKnight,
                             pagefault (pagefault@zsnes.com),
                             Kris Bleakley
                             Ported from x86 assembler to C by sanmaiwashi

  SPC7110 and RTC C++ emulator code used in 1.39-1.51
  (c) Copyright 2002         Matthew Kendora with research by
                             zsKnight,
                             John Weidman,
                             Dark Force

  SPC7110 and RTC C++ emulator code used in 1.52+
  (c) Copyright 2009         byuu,
                             neviksti

  S-DD1 C emulator code
  (c) Copyright 2003         Brad Jorsch with research by
                             Andreas Naive,
                             John Weidman

  S-RTC C emulator code
  (c) Copyright 2001 - 2006  byuu,
                             John Weidman

  ST010 C++ emulator code
  (c) Copyright 2003         Feather,
                             John Weidman,
                             Kris Bleakley,
                             Matthew Kendora

  Super FX x86 assembler emulator code
  (c) Copyright 1998 - 2003  _Demo_,
                             pagefault,
                             zsKnight

  Super FX C emulator code
  (c) Copyright 1997 - 1999  Ivar,
                             Gary Henderson,
                             John Weidman

  Sound emulator code used in 1.5-1.51
  (c) Copyright 1998 - 2003  Brad Martin
  (c) Copyright 1998 - 2006  Charles Bilyue'

  Sound emulator code used in 1.52+
  (c) Copyright 2004 - 2007  Shay Green (gblargg@gmail.com)

  S-SMP emulator code used in 1.54+
  (c) Copyright 2016         byuu

  SH assembler code partly based on x86 assembler code
  (c) Copyright 2002 - 2004  Marcus Comstedt (marcus@mc.pp.se)

  2xSaI filter
  (c) Copyright 1999 - 2001  Derek Liauw Kie Fa

  HQ2x, HQ3x, HQ4x filters
  (c) Copyright 2003         Maxim Stepin (maxim@hiend3d.com)

  NTSC filter
  (c) Copyright 2006 - 2007  Shay Green

  GTK+ GUI code
  (c) Copyright 2004 - 2018  BearOso

  Win32 GUI code
  (c) Copyright 2003 - 2006  blip,
                             funkyass,
                             Matthew Kendora,
                             Nach,
                             nitsuja
  (c) Copyright 2009 - 2018  OV2

  Mac OS GUI code
  (c) Copyright 1998 - 2001  John Stiles
  (c) Copyright 2001 - 2011  zones

  Libretro port
  (c) Copyright 2011 - 2017  Hans-Kristian Arntzen,
                             Daniel De Matteis
                             (Under no circumstances will commercial rights be given)


  Specific ports contains the works of other authors. See headers in
  individual files.


  Snes9x homepage: http://www.snes9x.com/

  Permission to use, copy, modify and/or distribute Snes9x in both binary
  and source form, for non-commercial purposes, is hereby granted without
  fee, providing that this license information and copyright notice appear
  with all copies and any derived work.

  This software is provided 'as-is', without any express or implied
  warranty. In no event shall the authors be held liable for any damages
  arising from the use of this software or it's derivatives.

  Snes9x is freeware for PERSONAL USE only. Commercial users should
  seek permission of the copyright holders first. Commercial use includes,
  but is not limited to, charging money for Snes9x or software derived from
  Snes9x, including Snes9x or derivatives in commercial game bundles, and/or
  using Snes9x as a promotion for your commercial product.

  The copyright holders request that bug fixes and improvements to the code
  should be forwarded to them so everyone can benefit from the modifications
  in future versions.

  Super NES and Super Nintendo Entertainment System are trademarks of
  Nintendo Co., Limited and its subsidiary companies.
 ***********************************************************************************/


#ifndef _FXINST_H_
#define _FXINST_H_

/*
 * FxChip(GSU) register space specification
 * (Register address space 3000-32ff)
 *
 * The 16 generic 16 bit registers:
 * (Some have a special function in special circumstances)
 * 3000 - R0    default source/destination register
 * 3002 - R1    pixel plot X position register
 * 3004 - R2    pixel plot Y position register
 * 3006 - R3
 * 3008 - R4    lower 16 bit result of lmult
 * 300a - R5
 * 300c - R6    multiplier for fmult and lmult
 * 300e - R7    fixed point texel X position for merge
 * 3010 - R8    fixed point texel Y position for merge
 * 3012 - R9
 * 3014 - R10
 * 3016 - R11   return address set by link
 * 3018 - R12   loop counter
 * 301a - R13   loop point address
 * 301c - R14   rom address for getb, getbh, getbl, getbs
 * 301e - R15   program counter
 *
 * 3020-302f -  unused
 *
 * Other internal registers
 * 3030 - SFR   status flag register  (16bit)
 * 3032 - unused
 * 3033 - BRAMR Backup RAM register    (8bit)
 * 3034 - PBR   program bank register  (8bit)
 * 3035 - unused
 * 3036 - ROMBR rom bank register      (8bit)
 * 3037 - CFGR  control flags register (8bit)
 * 3038 - SCBR  screen base register   (8bit)
 * 3039 - CLSR  clock speed register   (8bit)
 * 303a - SCMR  screen mode register   (8bit)
 * 303b - VCR   version code register  (8bit) (read only)
 * 303c - RAMBR ram bank register      (8bit)
 * 303d - unused
 * 303e - CBR   cache base register   (16bit)
 *
 * 3040-30ff -  unused
 *
 * 3100-32ff -  CACHERAM 512 bytes of GSU cache memory
 *
 * SFR status flag register bits:
 *  0   -
 *  1   Z     Zero flag
 *  2   CY    Carry flag
 *  3   S     Sign flag
 *  4   OV    Overflow flag
 *  5   G     Go flag (set to 1 when the GSU is running)
 *  6   R     Set to 1 when reading ROM using R14 address
 *  7   -
 *  8   ALT1  Mode set-up flag for the next instruction
 *  9   ALT2  Mode set-up flag for the next instruction
 * 10   IL    Immediate lower 8-bit flag
 * 11   IH    Immediate higher 8-bit flag
 * 12   B     Set to 1 when the WITH instruction is executed
 * 13   -
 * 14   -
 * 15   IRQ   Set to 1 when GSU caused an interrupt
 *            Set to 0 when read by 658c16
 *
 * BRAMR = 0, BackupRAM is disabled
 * BRAMR = 1, BackupRAM is enabled
 *
 * CFGR control flags register bits:
 *  0   -
 *  1   -
 *  2   -
 *  3   -
 *  4   -
 *  5   MS0   Multiplier speed, 0=standard, 1=high speed
 *  6   -
 *  7   IRQ   Set to 1 when GSU interrupt request is masked
 *
 * CLSR clock speed register bits:
 *  0   CLSR  clock speed, 0 = 10.7Mhz, 1 = 21.4Mhz
 *
 * SCMR screen mode register bits:
 *  0	MD0   color depth mode bit 0
 *  1	MD1   color depth mode bit 1
 *  2	HT0   screen height bit 1
 *  3	RAN   RAM access control
 *  4	RON   ROM access control
 *  5	HT1   screen height bit 2
 *  6	-
 *  7	-
 *
 * RON = 0    SNES CPU has ROM access
 * RON = 1    GSU has ROM access
 *
 * RAN = 0    SNES has game pak RAM access
 * RAN = 1    GSU has game pak RAM access
 *
 * HT1  HT0   Screen height mode
 *  0    0    128 pixels high
 *  0    1    160 pixels high
 *  1    0    192 pixels high
 *  1    1    OBJ mode
 *
 * MD1  MD0   Color depth mode
 *  0    0    4   color mode
 *  0    1    16  color mode
 *  1    0    not used
 *  1    1    256 color mode
 *
 * CBR cache base register bits:
 * 15-4       Specify base address for data to cache from ROM or RAM
 *  3-0       Are 0 when address is read
 *
 * Write access to the program counter (301e) from
 * the SNES-CPU will start the GSU, and it will not
 * stop until it reaches a stop instruction.
 *
 */

// Number of banks in GSU RAM
#define FX_RAM_BANKS	4

// Emulate proper R14 ROM access (slower, but safer)
#define FX_DO_ROMBUFFER

// Address checking (definately slow)
//#define FX_ADDRESS_CHECK

struct FxRegs_s
{
	// FxChip registers
	uint32	avReg[16];					// 16 Generic registers
	uint32	vColorReg;					// Internal color register
	uint32	vPlotOptionReg;				// Plot option register
	uint32	vStatusReg;					// Status register
	uint32	vPrgBankReg;				// Program bank index register
	uint32	vRomBankReg;				// Rom bank index register
	uint32	vRamBankReg;				// Ram bank index register
	uint32	vCacheBaseReg;				// Cache base address register
	uint32	vCacheFlags;				// Saying what parts of the cache was written to
	uint32	vLastRamAdr;				// Last RAM address accessed
	uint32	*pvDreg;					// Pointer to current destination register
	uint32	*pvSreg;					// Pointer to current source register
	uint8	vRomBuffer;					// Current byte read by R14
	uint8	vPipe;						// Instructionset pipe
	uint32	vPipeAdr;					// The address of where the pipe was read from

	// Status register optimization stuff
	uint32	vSign;						// v & 0x8000
	uint32	vZero;						// v == 0
	uint32	vCarry;						// a value of 1 or 0
	int32	vOverflow;					// (v >= 0x8000 || v < -0x8000)

	// Other emulator variables
	int32	vErrorCode;
	uint32	vIllegalAddress;

	uint8	bBreakPoint;
	uint32	vBreakPoint;
	uint32	vStepPoint;

	uint8	*pvRegisters;				// 768 bytes located in the memory at address 0x3000
	uint32	nRamBanks;					// Number of 64kb-banks in FxRam (Don't confuse it with SNES-Ram!!!)
	uint8	*pvRam;						// Pointer to FxRam
	uint32	nRomBanks;					// Number of 32kb-banks in Cart-ROM
	uint8	*pvRom;						// Pointer to Cart-ROM

	uint32	vMode;						// Color depth/mode
	uint32	vPrevMode;					// Previous depth
	uint8	*pvScreenBase;
	uint8	*apvScreen[32];				// Pointer to each of the 32 screen colums
	int32	x[32];
	uint32	vScreenHeight;				// 128, 160, 192 or 256 (could be overriden by cmode)
	uint32	vScreenRealHeight;			// 128, 160, 192 or 256
	uint32	vPrevScreenHeight;
	uint32	vScreenSize;
	void	(*pfPlot) (void);
	void	(*pfRpix) (void);

	uint8	*pvRamBank;					// Pointer to current RAM-bank
	uint8	*pvRomBank;					// Pointer to current ROM-bank
	uint8	*pvPrgBank;					// Pointer to current program ROM-bank

	uint8	*apvRamBank[FX_RAM_BANKS];	// Ram bank table (max 256kb)
	uint8	*apvRomBank[256];			// Rom bank table

	uint8	bCacheActive;
	uint8	*pvCache;					// Pointer to the GSU cache
	uint8	avCacheBackup[512];			// Backup of ROM when the cache has replaced it
	uint32	vCounter;
	uint32	vInstCount;
	uint32	vSCBRDirty;					// If SCBR is written, our cached screen pointers need updating
	
	uint8	*avRegAddr;					// To reference avReg in snapshot.cpp
};

extern struct FxRegs_s	GSU;

// GSU registers
#define GSU_R0			0x000
#define GSU_R1			0x002
#define GSU_R2			0x004
#define GSU_R3			0x006
#define GSU_R4			0x008
#define GSU_R5			0x00a
#define GSU_R6			0x00c
#define GSU_R7			0x00e
#define GSU_R8			0x010
#define GSU_R9			0x012
#define GSU_R10			0x014
#define GSU_R11			0x016
#define GSU_R12			0x018
#define GSU_R13			0x01a
#define GSU_R14			0x01c
#define GSU_R15			0x01e
#define GSU_SFR			0x030
#define GSU_BRAMR		0x033
#define GSU_PBR			0x034
#define GSU_ROMBR		0x036
#define GSU_CFGR		0x037
#define GSU_SCBR		0x038
#define GSU_CLSR		0x039
#define GSU_SCMR		0x03a
#define GSU_VCR			0x03b
#define GSU_RAMBR		0x03c
#define GSU_CBR			0x03e
#define GSU_CACHERAM	0x100

// SFR flags
#define FLG_Z			(1 <<  1)
#define FLG_CY			(1 <<  2)
#define FLG_S			(1 <<  3)
#define FLG_OV			(1 <<  4)
#define FLG_G			(1 <<  5)
#define FLG_R			(1 <<  6)
#define FLG_ALT1		(1 <<  8)
#define FLG_ALT2		(1 <<  9)
#define FLG_IL			(1 << 10)
#define FLG_IH			(1 << 11)
#define FLG_B			(1 << 12)
#define FLG_IRQ			(1 << 15)

// Test flag
#define TF(a)			(GSU.vStatusReg &   FLG_##a)
#define CF(a)			(GSU.vStatusReg &= ~FLG_##a)
#define SF(a)			(GSU.vStatusReg |=  FLG_##a)

// Test and set flag if condition, clear if not
#define TS(a, b)		GSU.vStatusReg = ((GSU.vStatusReg & (~FLG_##a)) | ((!!(##b)) * FLG_##a))

// Testing ALT1 & ALT2 bits
#define ALT0			(!TF(ALT1) && !TF(ALT2))
#define ALT1			( TF(ALT1) && !TF(ALT2))
#define ALT2			(!TF(ALT1) &&  TF(ALT2))
#define ALT3			( TF(ALT1) &&  TF(ALT2))

// Sign extend from 8/16 bit to 32 bit
#define SEX8(a)			((int32)  ((int8)   (a)))
#define SEX16(a)		((int32)  ((int16)  (a)))

// Unsign extend from 8/16 bit to 32 bit
#define USEX8(a)		((uint32) ((uint8)  (a)))
#define USEX16(a)		((uint32) ((uint16) (a)))
#define SUSEX16(a)		((int32)  ((uint16) (a)))

// Set/Clr Sign and Zero flag
#define TSZ(num)		TS(S, ((num) & 0x8000)); TS(Z, (!USEX16(num)))

// Clear flags
#define CLRFLAGS		GSU.vStatusReg &= ~(FLG_ALT1 | FLG_ALT2 | FLG_B); GSU.pvDreg = GSU.pvSreg = &R0

// Read current RAM-Bank
#define RAM(adr)		GSU.pvRamBank[USEX16(adr)]

// Read current ROM-Bank
#define ROM(idx)		GSU.pvRomBank[USEX16(idx)]

// Access the current value in the pipe
#define PIPE			GSU.vPipe

// Access data in the current program bank
#define PRGBANK(idx)	GSU.pvPrgBank[USEX16(idx)]

// Update pipe from ROM
#if 0
#define FETCHPIPE		{ PIPE = PRGBANK(R15); GSU.vPipeAdr = (GSU.vPrgBankReg << 16) + R15; }
#else
#define FETCHPIPE		{ PIPE = PRGBANK(R15); }
#endif

// ABS
#define ABS(x)			((x) < 0 ? -(x) : (x))

// Access source register
#define SREG			(*GSU.pvSreg)

// Access destination register
#define DREG			(*GSU.pvDreg)

#ifndef FX_DO_ROMBUFFER

// Don't read R14
#define READR14

// Don't test and/or read R14
#define TESTR14

#else

// Read R14
#define READR14			GSU.vRomBuffer = ROM(R14)

// Test and/or read R14
#define TESTR14			if (GSU.pvDreg == &R14) READR14

#endif

// Access to registers
#define R0				GSU.avReg[0]
#define R1				GSU.avReg[1]
#define R2				GSU.avReg[2]
#define R3				GSU.avReg[3]
#define R4				GSU.avReg[4]
#define R5				GSU.avReg[5]
#define R6				GSU.avReg[6]
#define R7				GSU.avReg[7]
#define R8				GSU.avReg[8]
#define R9				GSU.avReg[9]
#define R10				GSU.avReg[10]
#define R11				GSU.avReg[11]
#define R12				GSU.avReg[12]
#define R13				GSU.avReg[13]
#define R14				GSU.avReg[14]
#define R15				GSU.avReg[15]
#define SFR				GSU.vStatusReg
#define PBR				GSU.vPrgBankReg
#define ROMBR			GSU.vRomBankReg
#define RAMBR			GSU.vRamBankReg
#define CBR				GSU.vCacheBaseReg
#define SCBR			USEX8(GSU.pvRegisters[GSU_SCBR])
#define SCMR			USEX8(GSU.pvRegisters[GSU_SCMR])
#define COLR			GSU.vColorReg
#define POR				GSU.vPlotOptionReg
#define BRAMR			USEX8(GSU.pvRegisters[GSU_BRAMR])
#define VCR				USEX8(GSU.pvRegisters[GSU_VCR])
#define CFGR			USEX8(GSU.pvRegisters[GSU_CFGR])
#define CLSR			USEX8(GSU.pvRegisters[GSU_CLSR])

// Execute instruction from the pipe, and fetch next byte to the pipe
#define FX_STEP \
{ \
	uint32	vOpcode = (uint32) PIPE; \
	FETCHPIPE; \
	(*fx_OpcodeTable[(GSU.vStatusReg & 0x300) | vOpcode])(); \
}

extern void (*fx_PlotTable[]) (void);
extern void (*fx_OpcodeTable[]) (void);

// Set this define if branches are relative to the instruction in the delay slot (I think they are)
#define BRANCH_DELAY_RELATIVE

#endif