/***************************************************************************

    Neo-Geo hardware protection devices

    unknown devices
        ssideki, fatfury2, fatfury3, kof98, mslugx

    SMA chip
        kof99, garou, garouo, mslug3, kof2002

        custom banking, random number generator
        encryption (see machine/neocrypt.c)
        internal rom data

    PVC chip
        mslug5, kof2003, svcchaos

***************************************************************************/

#include "driver.h"
#include "neogeo.h"



static UINT32 fatfury2_prot_data;
static UINT16 neogeo_rng;

static UINT16 *pvc_cartridge_ram;


/************************ Fatal Fury 2 *************************/

static READ16_HANDLER( fatfury2_protection_16_r )
{
	UINT16 res = fatfury2_prot_data >> 24;

	switch (offset)
	{
		case 0x55550/2:
		case 0xffff0/2:
		case 0x00000/2:
		case 0xff000/2:
		case 0x36000/2:
		case 0x36008/2:
			return res;

		case 0x36004/2:
		case 0x3600c/2:
			return ((res & 0xf0) >> 4) | ((res & 0x0f) << 4);

		default:
logerror("unknown protection read at pc %06x, offset %08x\n",activecpu_get_pc(),offset<<1);
			return 0;
	}
}


static WRITE16_HANDLER( fatfury2_protection_16_w )
{
	switch (offset)
	{
		case 0x11112/2: /* data == 0x1111; expects 0xff000000 back */
			fatfury2_prot_data = 0xff000000;
			break;

		case 0x33332/2: /* data == 0x3333; expects 0x0000ffff back */
			fatfury2_prot_data = 0x0000ffff;
			break;

		case 0x44442/2: /* data == 0x4444; expects 0x00ff0000 back */
			fatfury2_prot_data = 0x00ff0000;
			break;

		case 0x55552/2: /* data == 0x5555; read back from 55550, ffff0, 00000, ff000 */
			fatfury2_prot_data = 0xff00ff00;
			break;

		case 0x56782/2: /* data == 0x1234; read back from 36000 *or* 36004 */
			fatfury2_prot_data = 0xf05a3601;
			break;

		case 0x42812/2: /* data == 0x1824; read back from 36008 *or* 3600c */
			fatfury2_prot_data = 0x81422418;
			break;

		case 0x55550/2:
		case 0xffff0/2:
		case 0xff000/2:
		case 0x36000/2:
		case 0x36004/2:
		case 0x36008/2:
		case 0x3600c/2:
			fatfury2_prot_data <<= 8;
			break;

		default:
			logerror("unknown protection write at pc %06x, offset %08x, data %02x\n",activecpu_get_pc(),offset,data);
			break;
	}
}


void fatfury2_install_protection(void)
{
	/* the protection involves reading and writing addresses in the */
	/* 0x2xxxxx range. There are several checks all around the code. */
	memory_install_readwrite16_handler(0, ADDRESS_SPACE_PROGRAM, 0x200000, 0x2fffff, 0, 0, fatfury2_protection_16_r, fatfury2_protection_16_w);

	state_save_register_global(fatfury2_prot_data);
}



/************************ King of Fighters 98*******************
  The encrypted set has a rom overlay feature, checked at
  various points in the game
***************************************************************/

static WRITE16_HANDLER ( kof98_prot_w )
{
	/* info from razoola */
	UINT16* mem16 = (UINT16*)memory_region(NEOGEO_REGION_MAIN_CPU_CARTRIDGE);

	switch (data)
	{
		case 0x0090:
		logerror ("%06x kof98 - protection 0x0090 old %04x %04x\n",activecpu_get_pc(), mem16[0x100/2], mem16[0x102/2]);
		mem16[0x100/2] = 0x00c2; mem16[0x102/2] = 0x00fd;
		break;

		case 0x00f0:
		logerror ("%06x kof98 - protection 0x00f0 old %04x %04x\n",activecpu_get_pc(), mem16[0x100/2], mem16[0x102/2]);
		mem16[0x100/2] = 0x4e45; mem16[0x102/2] = 0x4f2d;
		break;

		default: // 00aa is written, but not needed?
		logerror ("%06x kof98 - unknown protection write %04x\n",activecpu_get_pc(), data);
		break;
	}
}


void install_kof98_protection(void)
{
	/* when 0x20aaaa contains 0x0090 (word) then 0x100 (normally the neogeo header) should return 0x00c200fd
   worked out using real hw */

	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x20aaaa, 0x20aaab, 0, 0, kof98_prot_w);
}



/************************ Metal Slug X *************************
  todo: emulate, not patch!
***************************************************************/

void mslugx_install_protection(void)
{
	int i;
	UINT16 *mem16 = (UINT16 *)memory_region(NEOGEO_REGION_MAIN_CPU_CARTRIDGE);

	for (i = 0;i < (0x100000/2) - 4;i++)
	{
		if (mem16[i+0] == 0x0243 &&
			mem16[i+1] == 0x0001 && 	/* andi.w  #$1, D3 */
			mem16[i+2] == 0x6600)		/* bne xxxx */
		{
			mem16[i+2] = 0x4e71;
			mem16[i+3] = 0x4e71;
		}
	}
	mem16[0x3bdc/2] = 0x4e71;
	mem16[0x3bde/2] = 0x4e71;
	mem16[0x3be0/2] = 0x4e71;
	mem16[0x3c0c/2] = 0x4e71;
	mem16[0x3c0e/2] = 0x4e71;
	mem16[0x3c10/2] = 0x4e71;

	mem16[0x3c36/2] = 0x4e71;
	mem16[0x3c38/2] = 0x4e71;
}



/************************ SMA Protection************************
  thanks to Razoola
***************************************************************/

static WRITE16_HANDLER( kof99_bankswitch_w )
{
	int bankaddress;
	static const int bankoffset[64] =
	{
		0x000000, 0x100000, 0x200000, 0x300000,
		0x3cc000, 0x4cc000, 0x3f2000, 0x4f2000,
		0x407800, 0x507800, 0x40d000, 0x50d000,
		0x417800, 0x517800, 0x420800, 0x520800,
		0x424800, 0x524800, 0x429000, 0x529000,
		0x42e800, 0x52e800, 0x431800, 0x531800,
		0x54d000, 0x551000, 0x567000, 0x592800,
		0x588800, 0x581800, 0x599800, 0x594800,
		0x598000,	/* rest not used? */
	};

	/* unscramble bank number */
	data =
		(((data>>14)&1)<<0)+
		(((data>> 6)&1)<<1)+
		(((data>> 8)&1)<<2)+
		(((data>>10)&1)<<3)+
		(((data>>12)&1)<<4)+
		(((data>> 5)&1)<<5);

	bankaddress = 0x100000 + bankoffset[data];

	neogeo_set_main_cpu_bank_address(bankaddress);
}


static WRITE16_HANDLER( garou_bankswitch_w )
{
	/* thanks to Razoola and Mr K for the info */
	int bankaddress;
	static const int bankoffset[64] =
	{
		0x000000, 0x100000, 0x200000, 0x300000, // 00
		0x280000, 0x380000, 0x2d0000, 0x3d0000, // 04
		0x2f0000, 0x3f0000, 0x400000, 0x500000, // 08
		0x420000, 0x520000, 0x440000, 0x540000, // 12
		0x498000, 0x598000, 0x4a0000, 0x5a0000, // 16
		0x4a8000, 0x5a8000, 0x4b0000, 0x5b0000, // 20
		0x4b8000, 0x5b8000, 0x4c0000, 0x5c0000, // 24
		0x4c8000, 0x5c8000, 0x4d0000, 0x5d0000, // 28
		0x458000, 0x558000, 0x460000, 0x560000, // 32
		0x468000, 0x568000, 0x470000, 0x570000, // 36
		0x478000, 0x578000, 0x480000, 0x580000, // 40
		0x488000, 0x588000, 0x490000, 0x590000, // 44
		0x5d0000, 0x5d8000, 0x5e0000, 0x5e8000, // 48
		0x5f0000, 0x5f8000, 0x600000, /* rest not used? */
	};

	/* unscramble bank number */
	data =
		(((data>> 5)&1)<<0)+
		(((data>> 9)&1)<<1)+
		(((data>> 7)&1)<<2)+
		(((data>> 6)&1)<<3)+
		(((data>>14)&1)<<4)+
		(((data>>12)&1)<<5);

	bankaddress = 0x100000 + bankoffset[data];

	neogeo_set_main_cpu_bank_address(bankaddress);
}


static WRITE16_HANDLER( garouo_bankswitch_w )
{
	/* thanks to Razoola and Mr K for the info */
	int bankaddress;
	static const int bankoffset[64] =
	{
		0x000000, 0x100000, 0x200000, 0x300000, // 00
		0x280000, 0x380000, 0x2d0000, 0x3d0000, // 04
		0x2c8000, 0x3c8000, 0x400000, 0x500000, // 08
		0x420000, 0x520000, 0x440000, 0x540000, // 12
		0x598000, 0x698000, 0x5a0000, 0x6a0000, // 16
		0x5a8000, 0x6a8000, 0x5b0000, 0x6b0000, // 20
		0x5b8000, 0x6b8000, 0x5c0000, 0x6c0000, // 24
		0x5c8000, 0x6c8000, 0x5d0000, 0x6d0000, // 28
		0x458000, 0x558000, 0x460000, 0x560000, // 32
		0x468000, 0x568000, 0x470000, 0x570000, // 36
		0x478000, 0x578000, 0x480000, 0x580000, // 40
		0x488000, 0x588000, 0x490000, 0x590000, // 44
		0x5d8000, 0x6d8000, 0x5e0000, 0x6e0000, // 48
		0x5e8000, 0x6e8000, 0x6e8000, 0x000000, // 52
		0x000000, 0x000000, 0x000000, 0x000000, // 56
		0x000000, 0x000000, 0x000000, 0x000000, // 60
	};

	/* unscramble bank number */
	data =
		(((data>> 4)&1)<<0)+
		(((data>> 8)&1)<<1)+
		(((data>>14)&1)<<2)+
		(((data>> 2)&1)<<3)+
		(((data>>11)&1)<<4)+
		(((data>>13)&1)<<5);

	bankaddress = 0x100000 + bankoffset[data];

	neogeo_set_main_cpu_bank_address(bankaddress);
}


static WRITE16_HANDLER( mslug3_bankswitch_w )
{
	/* thanks to Razoola and Mr K for the info */
	int bankaddress;
	static const int bankoffset[64] =
	{
	  0x000000, 0x020000, 0x040000, 0x060000, // 00
	  0x070000, 0x090000, 0x0b0000, 0x0d0000, // 04
	  0x0e0000, 0x0f0000, 0x120000, 0x130000, // 08
	  0x140000, 0x150000, 0x180000, 0x190000, // 12
	  0x1a0000, 0x1b0000, 0x1e0000, 0x1f0000, // 16
	  0x200000, 0x210000, 0x240000, 0x250000, // 20
	  0x260000, 0x270000, 0x2a0000, 0x2b0000, // 24
	  0x2c0000, 0x2d0000, 0x300000, 0x310000, // 28
	  0x320000, 0x330000, 0x360000, 0x370000, // 32
	  0x380000, 0x390000, 0x3c0000, 0x3d0000, // 36
	  0x400000, 0x410000, 0x440000, 0x450000, // 40
	  0x460000, 0x470000, 0x4a0000, 0x4b0000, // 44
	  0x4c0000, /* rest not used? */
	};

	/* unscramble bank number */
	data =
		(((data>>14)&1)<<0)+
		(((data>>12)&1)<<1)+
		(((data>>15)&1)<<2)+
		(((data>> 6)&1)<<3)+
		(((data>> 3)&1)<<4)+
		(((data>> 9)&1)<<5);

	bankaddress = 0x100000 + bankoffset[data];

	neogeo_set_main_cpu_bank_address(bankaddress);
}


static WRITE16_HANDLER( kof2000_bankswitch_w )
{
	/* thanks to Razoola and Mr K for the info */
	int bankaddress;
	static const int bankoffset[64] =
	{
		0x000000, 0x100000, 0x200000, 0x300000, // 00
		0x3f7800, 0x4f7800, 0x3ff800, 0x4ff800, // 04
		0x407800, 0x507800, 0x40f800, 0x50f800, // 08
		0x416800, 0x516800, 0x41d800, 0x51d800, // 12
		0x424000, 0x524000, 0x523800, 0x623800, // 16
		0x526000, 0x626000, 0x528000, 0x628000, // 20
		0x52a000, 0x62a000, 0x52b800, 0x62b800, // 24
		0x52d000, 0x62d000, 0x52e800, 0x62e800, // 28
		0x618000, 0x619000, 0x61a000, 0x61a800, // 32
	};

	/* unscramble bank number */
	data =
		(((data>>15)&1)<<0)+
		(((data>>14)&1)<<1)+
		(((data>> 7)&1)<<2)+
		(((data>> 3)&1)<<3)+
		(((data>>10)&1)<<4)+
		(((data>> 5)&1)<<5);

	bankaddress = 0x100000 + bankoffset[data];

	neogeo_set_main_cpu_bank_address(bankaddress);
}


static READ16_HANDLER( prot_9a37_r )
{
	return 0x9a37;
}


/* information about the sma random number generator provided by razoola */
/* this RNG is correct for KOF99, other games might be different */

static READ16_HANDLER( sma_random_r )
{
	UINT16 old = neogeo_rng;

	UINT16 newbit = ((neogeo_rng >> 2) ^
					 (neogeo_rng >> 3) ^
					 (neogeo_rng >> 5) ^
					 (neogeo_rng >> 6) ^
					 (neogeo_rng >> 7) ^
					 (neogeo_rng >>11) ^
					 (neogeo_rng >>12) ^
					 (neogeo_rng >>15)) & 1;

	neogeo_rng = (neogeo_rng << 1) | newbit;

	return old;
}


void neogeo_reset_rng(void)
{
	neogeo_rng = 0x2345;
}


static void sma_install_random_read_handler(int addr1, int addr2)
{
	state_save_register_global(neogeo_rng);

	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, addr1, addr1 + 1, 0, 0, sma_random_r);
	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, addr2, addr2 + 2, 0, 0, sma_random_r);
}


void kof99_install_protection(void)
{
	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2ffff0, 0x2ffff1, 0, 0, kof99_bankswitch_w);
	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fe446, 0x2fe447, 0, 0, prot_9a37_r);

	sma_install_random_read_handler(0x2ffff8, 0x2ffffa);
}


void garou_install_protection(void)
{
	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fffc0, 0x2fffc1, 0, 0, garou_bankswitch_w);
	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fe446, 0x2fe447, 0, 0, prot_9a37_r);

	sma_install_random_read_handler(0x2fffcc, 0x2ffff0);
}


void garouo_install_protection(void)
{
	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fffc0, 0x2fffc1, 0, 0, garouo_bankswitch_w);
	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fe446, 0x2fe447, 0, 0, prot_9a37_r);

	sma_install_random_read_handler(0x2fffcc, 0x2ffff0);
}


void mslug3_install_protection(void)
{
	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fffe4, 0x2fffe5, 0, 0, mslug3_bankswitch_w);
	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fe446, 0x2fe447, 0, 0, prot_9a37_r);

//  sma_install_random_read_handler(0x2ffff8, 0x2ffffa);
}


void kof2000_install_protection(void)
{
	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fffec, 0x2fffed, 0, 0, kof2000_bankswitch_w);
	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fe446, 0x2fe447, 0, 0, prot_9a37_r);

	sma_install_random_read_handler(0x2fffd8, 0x2fffda);
}



/************************ PVC Protection ***********************
  mslug5, svcchaos, kof2003
***************************************************************/

static void pvc_w8(offs_t offset, UINT8 data)
{
	*(((UINT8*)pvc_cartridge_ram)+BYTE_XOR_LE(offset))=data;
}


static UINT8 pvc_r8(offs_t offset)
{
	return *(((UINT8*)pvc_cartridge_ram)+BYTE_XOR_LE(offset));
}


static void pvc_prot1( void )
{
	UINT8 b1, b2;
	b1 = pvc_r8(0x1fe1);
	b2 = pvc_r8(0x1fe0);
	pvc_w8(0x1fe2,(((b2>>0)&0xf)<<1)|((b1>>4)&1));
	pvc_w8(0x1fe3,(((b2>>4)&0xf)<<1)|((b1>>5)&1));
	pvc_w8(0x1fe4,(((b1>>0)&0xf)<<1)|((b1>>6)&1));
	pvc_w8(0x1fe5, (b1>>7));
}


static void pvc_prot2( void ) // on writes to e8/e9/ea/eb
{
	UINT8 b1, b2, b3, b4;
	b1 = pvc_r8(0x1fe9);
	b2 = pvc_r8(0x1fe8);
	b3 = pvc_r8(0x1feb);
	b4 = pvc_r8(0x1fea);
	pvc_w8(0x1fec,(b2>>1)|((b1>>1)<<4));
	pvc_w8(0x1fed,(b4>>1)|((b2&1)<<4)|((b1&1)<<5)|((b4&1)<<6)|((b3&1)<<7));
}


static void pvc_write_bankswitch( void )
{
	UINT32 bankaddress;
	bankaddress = ((pvc_cartridge_ram[0xff8]>>8)|(pvc_cartridge_ram[0xff9]<<8));
	*(((UINT8 *)pvc_cartridge_ram) + BYTE_XOR_LE(0x1ff0)) = 0xa0;
	*(((UINT8 *)pvc_cartridge_ram) + BYTE_XOR_LE(0x1ff1)) &= 0xfe;
	*(((UINT8 *)pvc_cartridge_ram) + BYTE_XOR_LE(0x1ff3)) &= 0x7f;
	neogeo_set_main_cpu_bank_address(bankaddress+0x100000);
}


static READ16_HANDLER( pvc_prot_r )
{
	return pvc_cartridge_ram[ offset ];
}


static WRITE16_HANDLER( pvc_prot_w )
{
	COMBINE_DATA( &pvc_cartridge_ram[ offset ] );
	if (offset == 0xff0)pvc_prot1();
	else if(offset >= 0xff4 && offset <= 0xff5)pvc_prot2();
	else if(offset >= 0xff8)pvc_write_bankswitch();
}


void install_pvc_protection( void )
{
	pvc_cartridge_ram = auto_malloc(0x2000);
	state_save_register_global_pointer(pvc_cartridge_ram, 0x2000 / 2);

	memory_install_readwrite16_handler(0, ADDRESS_SPACE_PROGRAM, 0x2fe000, 0x2fffff, 0, 0, pvc_prot_r, pvc_prot_w);
}
