/* * 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 #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) { static const short sms_offsets[] = { 0x7ff0, 0x3ff0, 0x1ff0 }; static const char *sms_exts[] = { "sms", "gg", "sg" }; static const char *md_exts[] = { "gen", "smd" }; char buff0[512], buff[32]; unsigned short *d16; pm_file *pmf; char ext[5]; int i; get_ext(fname, ext); // detect wrong extensions if (!strcmp(ext, ".srm") || !strcmp(ext, "s.gz") || !strcmp(ext, ".mds")) // s.gz ~ .mds.gz return PM_BAD_DETECT; /* don't believe in extensions, except .cue */ if (strcasecmp(ext, ".cue") == 0 || strcasecmp(ext, ".chd") == 0) return PM_CD; pmf = pm_open(fname); if (pmf == NULL) return PM_BAD_DETECT; if (pm_read(buff0, 512, pmf) != 512) { pm_close(pmf); return PM_BAD_DETECT; } if (strncasecmp("SEGADISCSYSTEM", buff0 + 0x00, 14) == 0 || strncasecmp("SEGADISCSYSTEM", buff0 + 0x10, 14) == 0) { pm_close(pmf); return PM_CD; } /* check for SMD evil */ if (pmf->size >= 0x4200 && (pmf->size & 0x3fff) == 0x200) { if (pm_seek(pmf, sms_offsets[0] + 0x200, SEEK_SET) == sms_offsets[0] + 0x200 && pm_read(buff, 16, pmf) == 16 && strncmp("TMR SEGA", buff, 8) == 0) goto looks_like_sms; /* could parse further but don't bother */ goto extension_check; } /* MD header? Act as TMSS BIOS here */ if (pm_seek(pmf, 0x100, SEEK_SET) == 0x100 && pm_read(buff, 16, pmf) == 16) { 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 (pm_seek(pmf, sms_offsets[i], SEEK_SET) != sms_offsets[i]) continue; if (pm_read(buff, 16, pmf) != 16) continue; 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(pmf->ext, md_exts[i]) == 0) goto looks_like_md; for (i = 0; i < ARRAY_SIZE(sms_exts); i++) if (strcasecmp(pmf->ext, sms_exts[i]) == 0) goto looks_like_sms; /* If everything else fails, make a guess on the reset vector */ d16 = (unsigned short *)(buff0 + 4); if ((((d16[0] << 16) | d16[1]) & 0xffffff) >= pmf->size) { 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; } /* 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 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; unsigned char *rom_data = NULL; unsigned int rom_size = 0; pm_file *rom = NULL; int cd_region = 0; int ret; media_type = detect_media(filename); 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; } rom = pm_open(rom_fname); if (rom == NULL) { lprintf("Failed to open ROM\n"); media_type = PM_ERROR; goto out; } ret = PicoCartLoad(rom, &rom_data, &rom_size, (PicoIn.AHW & PAHW_SMS) ? 1 : 0); pm_close(rom); 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) { if (strstr(filename,".gg")) { Pico.m.hardware |= 0x1; lprintf("detected GG 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_data) free(rom_data); return media_type; } // vim:shiftwidth=2:ts=2:expandtab