picodrive/pico/media.c

398 lines
10 KiB
C

/*
* PicoDrive
* (C) notaz, 2006-2010,2013
*
* This work is licensed under the terms of MAME license.
* See COPYING file in the top-level directory.
*/
#include <string.h>
#include "pico_int.h"
#include "cd/cd_parse.h"
unsigned char media_id_header[0x100];
static void strlwr_(char *string)
{
char *p;
for (p = string; *p; p++)
if ('A' <= *p && *p <= 'Z')
*p += 'a' - 'A';
}
static void get_ext(const char *file, char *ext)
{
const char *p;
p = file + strlen(file) - 4;
if (p < file) p = file;
strncpy(ext, p, 4);
ext[4] = 0;
strlwr_(ext);
}
static int detect_media(const char *fname, const unsigned char *rom, unsigned int romsize)
{
static const short sms_offsets[] = { 0x7ff0, 0x3ff0, 0x1ff0 };
static const char *sms_exts[] = { "sms", "gg", "sg" };
static const char *md_exts[] = { "gen", "smd", "md" };
static const char *pico_exts[] = { "pco" };
char buff0[512], buff[32];
unsigned short *d16 = NULL;
pm_file *pmf = NULL;
const char *ext_ptr = NULL;
char ext[8];
int i;
ext[0] = '\0';
if ((ext_ptr = strrchr(fname, '.'))) {
strncpy(ext, ext_ptr + 1, sizeof(ext));
ext[sizeof(ext) - 1] = '\0';
}
// detect wrong extensions
if (!strcmp(ext, "srm") || !strcmp(ext, "gz")) // s.gz ~ .mds.gz
return PM_BAD_DETECT;
/* don't believe in extensions, except .cue and .chd */
if (strcasecmp(ext, "cue") == 0 || strcasecmp(ext, "chd") == 0)
return PM_CD;
/* Open rom file, if required */
if (!rom) {
pmf = pm_open(fname);
if (pmf == NULL)
return PM_BAD_DETECT;
romsize = pmf->size;
}
if (!rom) {
if (pm_read(buff0, 512, pmf) != 512) {
pm_close(pmf);
return PM_BAD_DETECT;
}
} else {
if (romsize < 512)
return PM_BAD_DETECT;
memcpy(buff0, rom, 512);
}
if (strncasecmp("SEGADISCSYSTEM", buff0 + 0x00, 14) == 0 ||
strncasecmp("SEGADISCSYSTEM", buff0 + 0x10, 14) == 0) {
pm_close(pmf);
return PM_CD;
}
/* check for SMD evil */
if (romsize >= 0x4200 && (romsize & 0x3fff) == 0x200) {
buff[0] = '\0';
if (!rom) {
if (pm_seek(pmf, sms_offsets[0] + 0x200, SEEK_SET) == sms_offsets[0] + 0x200)
pm_read(buff, 16, pmf);
} else {
if (romsize >= sms_offsets[0] + 0x200 + 16)
memcpy(buff, rom + sms_offsets[0] + 0x200, 16);
}
if (strncmp("TMR SEGA", buff, 8) == 0)
goto looks_like_sms;
/* could parse further but don't bother */
goto extension_check;
}
/* fetch header info */
memset(buff, '\0', 17);
if (!rom) {
if (pm_seek(pmf, 0x100, SEEK_SET) == 0x100)
pm_read(buff, 16, pmf);
} else {
if (romsize >= 0x100 + 16)
memcpy(buff, rom + 0x100, 16);
}
/* PICO header? Almost always appropriately marked */
if (strstr(buff, " PICO "))
goto looks_like_pico;
/* MD header? Act as TMSS BIOS here */
if (strncmp(buff, "SEGA", 4) == 0 || strncmp(buff, " SEG", 4) == 0)
goto looks_like_md;
for (i = 0; i < ARRAY_SIZE(sms_offsets); i++) {
if (!rom) {
if (pm_seek(pmf, sms_offsets[i], SEEK_SET) != sms_offsets[i])
continue;
if (pm_read(buff, 16, pmf) != 16)
continue;
} else {
if (romsize < sms_offsets[i] + 16)
continue;
memcpy(buff, rom + sms_offsets[i], 16);
}
if (strncmp("TMR SEGA", buff, 8) == 0)
goto looks_like_sms;
}
extension_check:
/* probably some headerless thing. Maybe check the extension after all. */
for (i = 0; i < ARRAY_SIZE(md_exts); i++)
if (strcasecmp(ext, md_exts[i]) == 0)
goto looks_like_md;
for (i = 0; i < ARRAY_SIZE(sms_exts); i++)
if (strcasecmp(ext, sms_exts[i]) == 0)
goto looks_like_sms;
for (i = 0; i < ARRAY_SIZE(pico_exts); i++)
if (strcasecmp(ext, pico_exts[i]) == 0)
goto looks_like_pico;
/* If everything else fails, make a guess on the reset vector */
d16 = (unsigned short *)(buff0 + 4);
if ((((d16[0] << 16) | d16[1]) & 0xffffff) >= romsize) {
lprintf("bad MD reset vector, assuming SMS\n");
goto looks_like_sms;
}
d16 = (unsigned short *)(buff0 + 0x1a0);
if ((((d16[0] << 16) | d16[1]) & 0xffffff) != 0) {
lprintf("bad MD rom start, assuming SMS\n");
goto looks_like_sms;
}
looks_like_md:
pm_close(pmf);
return PM_MD_CART;
looks_like_sms:
pm_close(pmf);
return PM_MARK3;
looks_like_pico:
pm_close(pmf);
return PM_PICO;
}
/* checks if fname points to valid MegaCD image */
int PicoCdCheck(const char *fname_in, int *pregion)
{
const char *fname = fname_in;
unsigned char buf[32];
pm_file *cd_f;
int region = 4; // 1: Japan, 4: US, 8: Europe
char ext[5];
enum cd_track_type type = CT_UNKNOWN;
cd_data_t *cd_data = NULL;
// opens a cue, or searches for one
if (!cd_data && (cd_data = cue_parse(fname_in)) == NULL) {
get_ext(fname_in, ext);
if (strcasecmp(ext, ".cue") == 0)
return -1;
}
// opens a chd
if (!cd_data && (cd_data = chd_parse(fname_in)) == NULL) {
get_ext(fname_in, ext);
if (strcasecmp(ext, ".chd") == 0)
return -1;
}
if (cd_data != NULL) {
// 1st track contains the code
fname = cd_data->tracks[1].fname;
type = cd_data->tracks[1].type;
}
cd_f = pm_open(fname);
cdparse_destroy(cd_data);
if (cd_f == NULL) return CT_UNKNOWN; // let the upper level handle this
if (pm_read(buf, 32, cd_f) != 32) {
pm_close(cd_f);
return -1;
}
if (!strncasecmp("SEGADISCSYSTEM", (char *)buf+0x00, 14)) {
if (type && type != CT_ISO)
elprintf(EL_STATUS, ".cue has wrong type: %i", type);
type = CT_ISO; // Sega CD (ISO)
}
if (!strncasecmp("SEGADISCSYSTEM", (char *)buf+0x10, 14)) {
if (type && type != CT_BIN)
elprintf(EL_STATUS, ".cue has wrong type: %i", type);
type = CT_BIN; // Sega CD (BIN)
}
if (type == CT_UNKNOWN) {
pm_close(cd_f);
return 0;
}
pm_seek(cd_f, (type == CT_ISO) ? 0x100 : 0x110, SEEK_SET);
pm_read(media_id_header, sizeof(media_id_header), cd_f);
/* it seems we have a CD image here. Try to detect region now.. */
pm_seek(cd_f, (type == CT_ISO) ? 0x100+0x10B : 0x110+0x10B, SEEK_SET);
pm_read(buf, 1, cd_f);
pm_close(cd_f);
if (buf[0] == 0x64) region = 8; // EU
if (buf[0] == 0xa1) region = 1; // JAP
lprintf("detected %s Sega/Mega CD image with %s region\n",
type == CT_BIN ? "BIN" : "ISO", region != 4 ? (region == 8 ? "EU" : "JAP") : "USA");
if (pregion != NULL)
*pregion = region;
return type;
}
enum media_type_e PicoLoadMedia(const char *filename,
const unsigned char *rom, unsigned int romsize,
const char *carthw_cfg_fname,
const char *(*get_bios_filename)(int *region, const char *cd_fname),
void (*do_region_override)(const char *media_filename))
{
const char *rom_fname = filename;
enum media_type_e media_type;
enum cd_track_type cd_img_type = CT_UNKNOWN;
pm_file *rom_file = NULL;
unsigned char *rom_data = NULL;
unsigned int rom_size = 0;
int cd_region = 0;
int ret;
media_type = detect_media(filename, rom, romsize);
if (media_type == PM_BAD_DETECT)
goto out;
if ((PicoIn.AHW & PAHW_MCD) && Pico_mcd != NULL)
cdd_unload();
PicoCartUnload();
PicoIn.AHW = 0;
PicoIn.quirks = 0;
if (media_type == PM_CD)
{
// check for MegaCD image
cd_img_type = PicoCdCheck(filename, &cd_region);
if ((int)cd_img_type >= 0 && cd_img_type != CT_UNKNOWN)
{
// valid CD image, ask frontend for BIOS..
rom_fname = NULL;
if (get_bios_filename != NULL)
rom_fname = get_bios_filename(&cd_region, filename);
if (rom_fname == NULL) {
media_type = PM_BAD_CD_NO_BIOS;
goto out;
}
PicoIn.AHW |= PAHW_MCD;
}
else {
media_type = PM_BAD_CD;
goto out;
}
}
else if (media_type == PM_MARK3) {
PicoIn.AHW = PAHW_SMS;
}
else if (media_type == PM_PICO) {
PicoIn.AHW = PAHW_PICO;
}
if (!rom) {
rom_file = pm_open(rom_fname);
if (rom_file == NULL) {
lprintf("Failed to open ROM\n");
media_type = PM_ERROR;
goto out;
}
}
ret = PicoCartLoad(rom_file, rom, romsize, &rom_data, &rom_size, (PicoIn.AHW & PAHW_SMS) ? 1 : 0);
if (ret != 0) {
if (ret == 2) lprintf("Out of memory\n");
else if (ret == 3) lprintf("Read failed\n");
else lprintf("PicoCartLoad() failed.\n");
media_type = PM_ERROR;
goto out;
}
// detect wrong files
if (strncmp((char *)rom_data, "Pico", 4) == 0) {
lprintf("savestate selected?\n");
media_type = PM_BAD_DETECT;
goto out;
}
if (!(PicoIn.AHW & PAHW_SMS)) {
unsigned short *d = (unsigned short *)(rom_data + 4);
if ((((d[0] << 16) | d[1]) & 0xffffff) >= (int)rom_size) {
lprintf("bad reset vector\n");
media_type = PM_BAD_DETECT;
goto out;
}
}
// load config for this ROM (do this before insert to get correct region)
if (!(PicoIn.AHW & PAHW_MCD)) {
memcpy(media_id_header, rom_data + 0x100, sizeof(media_id_header));
if (do_region_override != NULL)
do_region_override(filename);
}
if (PicoCartInsert(rom_data, rom_size, carthw_cfg_fname)) {
media_type = PM_ERROR;
goto out;
}
rom_data = NULL; // now belongs to PicoCart
// simple test for GG. Do this here since m.hardware is nulled in Insert
if ((PicoIn.AHW & PAHW_SMS) && !PicoIn.hwSelect) {
const char *ext = NULL;
if (rom_file && rom_file->ext && (*rom_file->ext != '\0')) {
ext = rom_file->ext;
}
else if ((ext = strrchr(filename, '.'))) {
if (*(++ext) == '\0') {
ext = NULL;
}
}
if (ext && !strcmp(ext,"gg") && !PicoIn.hwSelect) {
Pico.m.hardware |= PMS_HW_GG;
lprintf("detected GG ROM\n");
} else if (ext && !strcmp(ext,"sg")) {
Pico.m.hardware |= PMS_HW_SG;
lprintf("detected SG-1000 ROM\n");
} else
lprintf("detected SMS ROM\n");
}
// insert CD if it was detected
Pico.m.ncart_in = 0;
if (cd_img_type != CT_UNKNOWN) {
ret = cdd_load(filename, cd_img_type);
if (ret != 0) {
PicoCartUnload();
media_type = PM_BAD_CD;
goto out;
}
Pico.m.ncart_in = 1;
}
if (PicoIn.quirks & PQUIRK_FORCE_6BTN)
PicoSetInputDevice(0, PICO_INPUT_PAD_6BTN);
out:
if (rom_file)
pm_close(rom_file);
if (rom_data)
free(rom_data);
return media_type;
}
// vim:shiftwidth=2:ts=2:expandtab