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- /*
- * 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)
- {
- 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
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