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Genesis-Plus-GX/source/loadrom.c
ekeeke31 e47ffcad81 fixed PICO ROM loading and region detection
2012-02-28 22:22:07 +00:00

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19 KiB
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/***************************************************************************************
* Genesis Plus
* ROM Loading Support
*
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Charles Mac Donald (original code)
* Copyright (C) 2007-2011 Eke-Eke (Genesis Plus GX)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:
*
* - Redistributions may not be sold, nor may they be used in a commercial
* product or activity.
*
* - Redistributions that are modified from the original source must include the
* complete source code, including the source code for all components used by a
* binary built from the modified sources. However, as a special exception, the
* source code distributed need not include anything that is normally distributed
* (in either source or binary form) with the major components (compiler, kernel,
* and so on) of the operating system on which the executable runs, unless that
* component itself accompanies the executable.
*
* - Redistributions must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************************/
#include <ctype.h>
#include "shared.h"
/*** ROM Information ***/
#define ROMCONSOLE 256
#define ROMCOPYRIGHT 272
#define ROMDOMESTIC 288
#define ROMWORLD 336
#define ROMTYPE 384
#define ROMPRODUCT 386
#define ROMCHECKSUM 398
#define ROMIOSUPPORT 400
#define ROMROMSTART 416
#define ROMROMEND 420
#define ROMRAMINFO 424
#define ROMRAMSTART 436
#define ROMRAMEND 440
#define ROMMODEMINFO 444
#define ROMMEMO 456
#define ROMCOUNTRY 496
#define P3BUTTONS 1
#define P6BUTTONS 2
#define PKEYBOARD 4
#define PPRINTER 8
#define PBALL 16
#define PFLOPPY 32
#define PACTIVATOR 64
#define PTEAMPLAYER 128
#define PMSYSTEMPAD 256
#define PSERIAL 512
#define PTABLET 1024
#define PPADDLE 2048
#define PCDROM 4096
#define PMOUSE 8192
#define MAXCOMPANY 64
#define MAXPERIPHERALS 14
typedef struct
{
char companyid[6];
char company[26];
} COMPANYINFO;
typedef struct
{
char pID[2];
char pName[14];
} PERIPHERALINFO;
ROMINFO rominfo;
char rom_filename[256];
uint8 romtype;
/***************************************************************************
* Genesis ROM Manufacturers
*
* Based on the document provided at
* http://www.zophar.net/tech/files/Genesis_ROM_Format.txt
**************************************************************************/
static const COMPANYINFO companyinfo[MAXCOMPANY] =
{
{"ACLD", "Ballistic"},
{"RSI", "Razorsoft"},
{"SEGA", "SEGA"},
{"TREC", "Treco"},
{"VRGN", "Virgin Games"},
{"WSTN", "Westone"},
{"10", "Takara"},
{"11", "Taito or Accolade"},
{"12", "Capcom"},
{"13", "Data East"},
{"14", "Namco or Tengen"},
{"15", "Sunsoft"},
{"16", "Bandai"},
{"17", "Dempa"},
{"18", "Technosoft"},
{"19", "Technosoft"},
{"20", "Asmik"},
{"22", "Micronet"},
{"23", "Vic Tokai"},
{"24", "American Sammy"},
{"29", "Kyugo"},
{"32", "Wolfteam"},
{"33", "Kaneko"},
{"35", "Toaplan"},
{"36", "Tecmo"},
{"40", "Toaplan"},
{"42", "UFL Company Limited"},
{"43", "Human"},
{"45", "Game Arts"},
{"47", "Sage's Creation"},
{"48", "Tengen"},
{"49", "Renovation or Telenet"},
{"50", "Electronic Arts"},
{"56", "Razorsoft"},
{"58", "Mentrix"},
{"60", "Victor Musical Ind."},
{"69", "Arena"},
{"70", "Virgin"},
{"73", "Soft Vision"},
{"74", "Palsoft"},
{"76", "Koei"},
{"79", "U.S. Gold"},
{"81", "Acclaim/Flying Edge"},
{"83", "Gametek"},
{"86", "Absolute"},
{"87", "Mindscape"},
{"93", "Sony"},
{"95", "Konami"},
{"97", "Tradewest"},
{"100", "T*HQ Software"},
{"101", "Tecmagik"},
{"112", "Designer Software"},
{"113", "Psygnosis"},
{"119", "Accolade"},
{"120", "Code Masters"},
{"125", "Interplay"},
{"130", "Activision"},
{"132", "Shiny & Playmates"},
{"144", "Atlus"},
{"151", "Infogrames"},
{"161", "Fox Interactive"},
{"177", "Ubisoft"},
{"239", "Disney Interactive"},
{"---", "Unknown"}
};
/***************************************************************************
* Genesis Peripheral Information
*
* Based on the document provided at
* http://www.zophar.net/tech/files/Genesis_ROM_Format.txt
***************************************************************************/
static const PERIPHERALINFO peripheralinfo[MAXPERIPHERALS] =
{
{"J", "3B Joypad"},
{"6", "6B Joypad"},
{"K", "Keyboard"},
{"P", "Printer"},
{"B", "Control Ball"},
{"F", "Floppy Drive"},
{"L", "Activator"},
{"4", "Team Player"},
{"0", "MS Joypad"},
{"R", "RS232C Serial"},
{"T", "Tablet"},
{"V", "Paddle"},
{"C", "CD-ROM"},
{"M", "Mega Mouse"},
};
/***************************************************************************
*
* Compute ROM real checksum.
***************************************************************************/
static uint16 getchecksum(uint8 *rom, int length)
{
int i;
uint16 checksum = 0;
for (i = 0; i < length; i += 2)
{
checksum += ((rom[i] << 8) + rom[i + 1]);
}
return checksum;
}
/***************************************************************************
*
* Pass a pointer to the ROM base address.
***************************************************************************/
static void getrominfo(char *romheader)
{
uint16 offset = 0;
/* Clear ROM info structure */
memset (&rominfo, 0, sizeof (ROMINFO));
/* Look for Master System ROM header */
if (!memcmp (&cart.rom[0x1ff0], "TMR SEGA", 8))
{
offset = 0x1ff0;
}
else if (!memcmp (&cart.rom[0x3ff0], "TMR SEGA", 8))
{
offset = 0x3ff0;
}
else if (!memcmp (&cart.rom[0x7ff0], "TMR SEGA", 8))
{
offset = 0x7ff0;
}
/* If found, assume this is a SMS game */
if (offset)
{
/* checksum */
rominfo.checksum = cart.rom[offset + 0x0a] | (cart.rom[offset + 0x0b] << 8);
/* product code & version */
sprintf(&rominfo.product[0], "%02d", cart.rom[offset + 0x0e] >> 4);
sprintf(&rominfo.product[2], "%02x", cart.rom[offset + 0x0d]);
sprintf(&rominfo.product[4], "%02x", cart.rom[offset + 0x0c]);
sprintf(&rominfo.product[6], "-%d", cart.rom[offset + 0x0e] & 0x0F);
/* region code */
switch (cart.rom[offset + 0x0f] >> 4)
{
case 3:
strcpy(rominfo.country,"SMS Japan");
break;
case 4:
strcpy(rominfo.country,"SMS Export");
break;
case 5:
strcpy(rominfo.country,"GG Japan");
break;
case 6:
strcpy(rominfo.country,"GG Export");
break;
case 7:
strcpy(rominfo.country,"GG International");
break;
default:
sprintf(rominfo.country,"Unknown (%d)", cart.rom[offset + 0x0f] >> 4);
break;
}
/* ROM size */
rominfo.romstart = 0;
switch (cart.rom[offset + 0x0f] & 0x0F)
{
case 0x00:
rominfo.romend = 0x3FFFF;
break;
case 0x01:
rominfo.romend = 0x7FFFF;
break;
case 0x02:
rominfo.romend = 0xFFFFF;
break;
case 0x0a:
rominfo.romend = 0x1FFF;
break;
case 0x0b:
rominfo.romend = 0x3FFF;
break;
case 0x0c:
rominfo.romend = 0x7FFF;
break;
case 0x0d:
rominfo.romend = 0xBFFF;
break;
case 0x0e:
rominfo.romend = 0xFFFF;
break;
case 0x0f:
rominfo.romend = 0x1FFFF;
break;
}
}
else
{
int i,j;
/* Some SMS games don't have any header */
if (system_hw != SYSTEM_MD) return;
/* Genesis ROM header support */
memcpy (&rominfo.consoletype, romheader + ROMCONSOLE, 16);
memcpy (&rominfo.copyright, romheader + ROMCOPYRIGHT, 16);
/* Domestic (japanese) name */
rominfo.domestic[0] = romheader[ROMDOMESTIC];
j = 1;
for (i=1; i<48; i++)
{
if ((rominfo.domestic[j-1] != 32) || (romheader[ROMDOMESTIC + i] != 32))
{
rominfo.domestic[j] = romheader[ROMDOMESTIC + i];
j++;
}
}
rominfo.domestic[j] = 0;
/* International name */
rominfo.international[0] = romheader[ROMWORLD];
j=1;
for (i=1; i<48; i++)
{
if ((rominfo.international[j-1] != 32) || (romheader[ROMWORLD + i] != 32))
{
rominfo.international[j] = romheader[ROMWORLD + i];
j++;
}
}
rominfo.international[j] = 0;
/* ROM informations */
memcpy (&rominfo.ROMType, romheader + ROMTYPE, 2);
memcpy (&rominfo.product, romheader + ROMPRODUCT, 12);
memcpy (&rominfo.checksum, romheader + ROMCHECKSUM, 2);
memcpy (&rominfo.romstart, romheader + ROMROMSTART, 4);
memcpy (&rominfo.romend, romheader + ROMROMEND, 4);
memcpy (&rominfo.country, romheader + ROMCOUNTRY, 16);
/* Checksums */
#ifdef LSB_FIRST
rominfo.checksum = (rominfo.checksum >> 8) | ((rominfo.checksum & 0xff) << 8);
#endif
rominfo.realchecksum = getchecksum(((uint8 *) cart.rom) + 0x200, cart.romsize - 0x200);
/* Supported peripherals */
rominfo.peripherals = 0;
for (i = 0; i < 14; i++)
for (j=0; j < 14; j++)
if (romheader[ROMIOSUPPORT+i] == peripheralinfo[j].pID[0])
rominfo.peripherals |= (1 << j);
}
}
/***************************************************************************
* deinterleave_block
*
* Convert interleaved (.smd) ROM files.
***************************************************************************/
static void deinterleave_block(uint8 * src)
{
int i;
uint8 block[0x4000];
memcpy (block, src, 0x4000);
for (i = 0; i < 0x2000; i += 1)
{
src[i * 2 + 0] = block[0x2000 + (i)];
src[i * 2 + 1] = block[0x0000 + (i)];
}
}
/***************************************************************************
* load_rom
*
* Load a new ROM file.
*
* Return 0 on error, 1 on success
*
***************************************************************************/
int load_rom(char *filename)
{
int i;
/* Load file into ROM buffer */
int size = load_archive(filename);
if (!size) return(0);
/* Auto-detect system mode from ROM file extension */
if (!strncmp(".sms", &filename[strlen(filename) - 4], 4))
{
/* Master System II hardware */
system_hw = SYSTEM_SMS2;
}
else if (!strncmp(".gg", &filename[strlen(filename) - 3], 3))
{
/* Game Gear hardware (GG mode) */
system_hw = SYSTEM_GG;
}
else if (!strncmp(".sg", &filename[strlen(filename) - 3], 3))
{
/* SG-1000 hardware */
system_hw = SYSTEM_SG;
}
else
{
/* Mega Drive hardware (Genesis mode) */
system_hw = SYSTEM_MD;
/* Decode .MDX format */
if (!strncmp(".mdx", &filename[strlen(filename) - 4], 4))
{
for (i = 4; i < size - 1; i++)
{
cart.rom[i-4] = cart.rom[i] ^ 0x40;
}
size = size - 5;
}
}
/* Take care of 512 byte header, if present */
if (strncmp((char *)(cart.rom + 0x100),"SEGA", 4) && ((size / 512) & 1))
{
size -= 512;
memcpy (cart.rom, cart.rom + 512, size);
/* interleaved ROM format (.smd) */
if (system_hw == SYSTEM_MD)
{
for (i = 0; i < (size / 0x4000); i++)
{
deinterleave_block (cart.rom + (i * 0x4000));
}
}
}
/* max. 10 MBytes supported */
if (size > MAXROMSIZE) size = MAXROMSIZE;
cart.romsize = size;
/* get infos from ROM header */
getrominfo((char *)cart.rom);
/* PICO hardware */
if (strstr(rominfo.consoletype, "SEGA PICO") != NULL)
{
system_hw = SYSTEM_PICO;
}
/* Save ROM type for later use */
romtype = system_hw;
/* Force system if requested */
if (config.system == SYSTEM_MD)
{
if (!(system_hw & SYSTEM_MD))
{
/* Mega Drive in MS compatibility mode */
system_hw = SYSTEM_PBC;
}
}
else if (config.system == SYSTEM_GG)
{
if (system_hw != SYSTEM_GG)
{
/* Game Gear in MS compatibility mode */
system_hw = SYSTEM_GGMS;
}
}
else if (config.system)
{
system_hw = config.system;
}
/* set console region */
region_autodetect();
/* Genesis mode specific */
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
#ifdef LSB_FIRST
/* Byteswap ROM to optimize 16-bit access */
uint8 temp;
for (i = 0; i < size; i += 2)
{
temp = cart.rom[i];
cart.rom[i] = cart.rom[i+1];
cart.rom[i+1] = temp;
}
#endif
/* byteswapped RADICA dumps (from Haze) */
if (((strstr(rominfo.product,"-K0101") != NULL) && (rominfo.checksum == 0xf424)) ||
((strstr(rominfo.product,"-K0109") != NULL) && (rominfo.checksum == 0x4f10)))
{
uint8 temp;
for(i = 0; i < size; i += 2)
{
temp = cart.rom[i];
cart.rom[i] = cart.rom[i+1];
cart.rom[i+1] = temp;
}
}
}
/* Master System or Game Gear BIOS ROM are loaded within $400000-$4FFFFF area */
if (size > 0x400000)
{
/* Mark both BIOS as unloaded if loaded ROM is overwriting them */
config.bios &= ~(SYSTEM_SMS | SYSTEM_GG);
}
return(1);
}
/****************************************************************************
* region_autodetect
*
* Set console region upon ROM header
*
****************************************************************************/
void region_autodetect(void)
{
if ((system_hw & SYSTEM_PBC) != SYSTEM_MD)
{
region_code = sms_cart_region_detect();
}
else
{
/* country codes used to differentiate region */
/* 0001 = japan ntsc (1) */
/* 0010 = japan pal (2) -> does not exist ? */
/* 0100 = usa (4) */
/* 1000 = europe (8) */
int country = 0;
/* from Gens */
if (!strncmp(rominfo.country, "eur", 3)) country |= 8;
else if (!strncmp(rominfo.country, "EUR", 3)) country |= 8;
else if (!strncmp(rominfo.country, "jap", 3)) country |= 1;
else if (!strncmp(rominfo.country, "JAP", 3)) country |= 1;
else if (!strncmp(rominfo.country, "usa", 3)) country |= 4;
else if (!strncmp(rominfo.country, "USA", 3)) country |= 4;
else
{
int i;
char c;
/* look for each characters */
for(i = 0; i < 4; i++)
{
c = toupper((int)rominfo.country[i]);
if (c == 'U') country |= 4;
else if (c == 'J') country |= 1;
else if (c == 'E') country |= 8;
else if (c == 'K') country |= 1;
else if (c < 16) country |= c;
else if ((c >= '0') && (c <= '9')) country |= c - '0';
else if ((c >= 'A') && (c <= 'F')) country |= c - 'A' + 10;
}
}
/* set default console region (USA > JAPAN > EUROPE) */
if (country & 4) region_code = REGION_USA;
else if (country & 1) region_code = REGION_JAPAN_NTSC;
else if (country & 8) region_code = REGION_EUROPE;
else if (country & 2) region_code = REGION_JAPAN_PAL;
else region_code = REGION_USA;
/* some games need specific REGION setting */
if (((strstr(rominfo.product,"T-45033") != NULL) && (rominfo.checksum == 0x0F81)) || /* Alisia Dragon (Europe) */
(strstr(rominfo.product,"T-69046-50") != NULL) || /* Back to the Future III (Europe) */
(strstr(rominfo.product,"T-120106-00") != NULL) || /* Brian Lara Cricket (Europe) */
(strstr(rominfo.product,"T-70096 -00") != NULL)) /* Muhammad Ali Heavyweight Boxing (Europe) */
{
/* need PAL settings */
region_code = REGION_EUROPE;
}
if ((rominfo.realchecksum == 0x532e) && (strstr(rominfo.product,"1011-00") != NULL))
{
/* On Dal Jang Goon (Korea) needs JAPAN region code */
region_code = REGION_JAPAN_NTSC;
}
}
/* force console region if requested */
if (config.region_detect == 1) region_code = REGION_USA;
else if (config.region_detect == 2) region_code = REGION_EUROPE;
else if (config.region_detect == 3) region_code = REGION_JAPAN_NTSC;
else if (config.region_detect == 4) region_code = REGION_JAPAN_PAL;
/* autodetect PAL/NTSC timings */
vdp_pal = (region_code >> 6) & 0x01;
/* autodetect PAL/NTSC master clock */
system_clock = vdp_pal ? MCLOCK_PAL : MCLOCK_NTSC;
/* force PAL/NTSC timings if requested */
if (config.vdp_mode == 1) vdp_pal = 0;
else if (config.vdp_mode == 2) vdp_pal = 1;
/* force PAL/NTSC master clock if requested */
if (config.master_clock == 1) system_clock = MCLOCK_NTSC;
else if (config.master_clock == 2) system_clock = MCLOCK_PAL;
}
/****************************************************************************
* get_company (Softdev - 2006)
*
* Try to determine which company made this rom
*
* Ok, for some reason there's no standard for this.
* It seems that there can be pretty much anything you like following the
* copyright (C) symbol!
****************************************************************************/
char *get_company(void)
{
char *s;
int i;
char company[10];
for (i = 3; i < 8; i++)
{
company[i - 3] = rominfo.copyright[i];
}
company[5] = 0;
/** OK, first look for a hyphen
* Capcom use T-12 for example
*/
s = strstr (company, "-");
if (s != NULL)
{
s++;
strcpy (company, s);
}
/** Strip any trailing spaces **/
for (i = strlen (company) - 1; i >= 0; i--)
if (company[i] == 32)
company[i] = 0;
if (strlen (company) == 0)
return (char *)companyinfo[MAXCOMPANY - 1].company;
for (i = 0; i < MAXCOMPANY - 1; i++)
{
if (!(strncmp (company, companyinfo[i].companyid, strlen (company))))
return (char *)companyinfo[i].company;
}
return (char *)companyinfo[MAXCOMPANY - 1].company;
}
/****************************************************************************
* get_peripheral (Softdev - 2006)
*
* Return peripheral name based on header code
*
****************************************************************************/
char *get_peripheral(int index)
{
if (index < MAXPERIPHERALS)
return (char *)peripheralinfo[index].pName;
return (char *)companyinfo[MAXCOMPANY - 1].company;
}
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