media.c 8.0 KB

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  1. /*
  2. * PicoDrive
  3. * (C) notaz, 2006-2010,2013
  4. *
  5. * This work is licensed under the terms of MAME license.
  6. * See COPYING file in the top-level directory.
  7. */
  8. #include <string.h>
  9. #include "pico_int.h"
  10. #include "cd/cd_parse.h"
  11. unsigned char media_id_header[0x100];
  12. static void strlwr_(char *string)
  13. {
  14. char *p;
  15. for (p = string; *p; p++)
  16. if ('A' <= *p && *p <= 'Z')
  17. *p += 'a' - 'A';
  18. }
  19. static void get_ext(const char *file, char *ext)
  20. {
  21. const char *p;
  22. p = file + strlen(file) - 4;
  23. if (p < file) p = file;
  24. strncpy(ext, p, 4);
  25. ext[4] = 0;
  26. strlwr_(ext);
  27. }
  28. static int detect_media(const char *fname)
  29. {
  30. static const short sms_offsets[] = { 0x7ff0, 0x3ff0, 0x1ff0 };
  31. static const char *sms_exts[] = { "sms", "gg", "sg" };
  32. static const char *md_exts[] = { "gen", "bin", "smd" };
  33. char buff0[32], buff[32];
  34. unsigned short *d16;
  35. pm_file *pmf;
  36. char ext[5];
  37. int i;
  38. get_ext(fname, ext);
  39. // detect wrong extensions
  40. if (!strcmp(ext, ".srm") || !strcmp(ext, "s.gz") || !strcmp(ext, ".mds")) // s.gz ~ .mds.gz
  41. return PM_BAD_DETECT;
  42. /* don't believe in extensions, except .cue */
  43. if (strcasecmp(ext, ".cue") == 0 || strcasecmp(ext, ".chd") == 0)
  44. return PM_CD;
  45. pmf = pm_open(fname);
  46. if (pmf == NULL)
  47. return PM_BAD_DETECT;
  48. if (pm_read(buff0, 32, pmf) != 32) {
  49. pm_close(pmf);
  50. return PM_BAD_DETECT;
  51. }
  52. if (strncasecmp("SEGADISCSYSTEM", buff0 + 0x00, 14) == 0 ||
  53. strncasecmp("SEGADISCSYSTEM", buff0 + 0x10, 14) == 0) {
  54. pm_close(pmf);
  55. return PM_CD;
  56. }
  57. /* check for SMD evil */
  58. if (pmf->size >= 0x4200 && (pmf->size & 0x3fff) == 0x200) {
  59. if (pm_seek(pmf, sms_offsets[0] + 0x200, SEEK_SET) == sms_offsets[0] + 0x200 &&
  60. pm_read(buff, 16, pmf) == 16 &&
  61. strncmp("TMR SEGA", buff, 8) == 0)
  62. goto looks_like_sms;
  63. /* could parse further but don't bother */
  64. goto extension_check;
  65. }
  66. /* MD header? Act as TMSS BIOS here */
  67. if (pm_seek(pmf, 0x100, SEEK_SET) == 0x100 && pm_read(buff, 16, pmf) == 16) {
  68. if (strncmp(buff, "SEGA", 4) == 0 || strncmp(buff, " SEG", 4) == 0)
  69. goto looks_like_md;
  70. }
  71. for (i = 0; i < ARRAY_SIZE(sms_offsets); i++) {
  72. if (pm_seek(pmf, sms_offsets[i], SEEK_SET) != sms_offsets[i])
  73. continue;
  74. if (pm_read(buff, 16, pmf) != 16)
  75. continue;
  76. if (strncmp("TMR SEGA", buff, 8) == 0)
  77. goto looks_like_sms;
  78. }
  79. extension_check:
  80. /* probably some headerless thing. Maybe check the extension after all. */
  81. for (i = 0; i < ARRAY_SIZE(md_exts); i++)
  82. if (strcasecmp(pmf->ext, md_exts[i]) == 0)
  83. goto looks_like_md;
  84. for (i = 0; i < ARRAY_SIZE(sms_exts); i++)
  85. if (strcasecmp(pmf->ext, sms_exts[i]) == 0)
  86. goto looks_like_sms;
  87. /* If everything else fails, make a guess on the reset vector */
  88. d16 = (unsigned short *)(buff0 + 4);
  89. if ((((d16[0] << 16) | d16[1]) & 0xffffff) >= pmf->size) {
  90. lprintf("bad MD reset vector, assuming SMS\n");
  91. goto looks_like_sms;
  92. }
  93. looks_like_md:
  94. pm_close(pmf);
  95. return PM_MD_CART;
  96. looks_like_sms:
  97. pm_close(pmf);
  98. return PM_MARK3;
  99. }
  100. /* checks if fname points to valid MegaCD image */
  101. int PicoCdCheck(const char *fname_in, int *pregion)
  102. {
  103. const char *fname = fname_in;
  104. unsigned char buf[32];
  105. pm_file *cd_f;
  106. int region = 4; // 1: Japan, 4: US, 8: Europe
  107. char ext[5];
  108. enum cd_track_type type = CT_UNKNOWN;
  109. cd_data_t *cd_data = NULL;
  110. // opens a cue, or searches for one
  111. if (!cd_data && (cd_data = cue_parse(fname_in)) == NULL) {
  112. get_ext(fname_in, ext);
  113. if (strcasecmp(ext, ".cue") == 0)
  114. return -1;
  115. }
  116. // opens a chd
  117. if (!cd_data && (cd_data = chd_parse(fname_in)) == NULL) {
  118. get_ext(fname_in, ext);
  119. if (strcasecmp(ext, ".chd") == 0)
  120. return -1;
  121. }
  122. if (cd_data != NULL) {
  123. // 1st track contains the code
  124. fname = cd_data->tracks[1].fname;
  125. type = cd_data->tracks[1].type;
  126. }
  127. cd_f = pm_open(fname);
  128. cdparse_destroy(cd_data);
  129. if (cd_f == NULL) return CT_UNKNOWN; // let the upper level handle this
  130. if (pm_read(buf, 32, cd_f) != 32) {
  131. pm_close(cd_f);
  132. return -1;
  133. }
  134. if (!strncasecmp("SEGADISCSYSTEM", (char *)buf+0x00, 14)) {
  135. if (type && type != CT_ISO)
  136. elprintf(EL_STATUS, ".cue has wrong type: %i", type);
  137. type = CT_ISO; // Sega CD (ISO)
  138. }
  139. if (!strncasecmp("SEGADISCSYSTEM", (char *)buf+0x10, 14)) {
  140. if (type && type != CT_BIN)
  141. elprintf(EL_STATUS, ".cue has wrong type: %i", type);
  142. type = CT_BIN; // Sega CD (BIN)
  143. }
  144. if (type == CT_UNKNOWN) {
  145. pm_close(cd_f);
  146. return 0;
  147. }
  148. pm_seek(cd_f, (type == CT_ISO) ? 0x100 : 0x110, SEEK_SET);
  149. pm_read(media_id_header, sizeof(media_id_header), cd_f);
  150. /* it seems we have a CD image here. Try to detect region now.. */
  151. pm_seek(cd_f, (type == CT_ISO) ? 0x100+0x10B : 0x110+0x10B, SEEK_SET);
  152. pm_read(buf, 1, cd_f);
  153. pm_close(cd_f);
  154. if (buf[0] == 0x64) region = 8; // EU
  155. if (buf[0] == 0xa1) region = 1; // JAP
  156. lprintf("detected %s Sega/Mega CD image with %s region\n",
  157. type == CT_BIN ? "BIN" : "ISO", region != 4 ? (region == 8 ? "EU" : "JAP") : "USA");
  158. if (pregion != NULL)
  159. *pregion = region;
  160. return type;
  161. }
  162. enum media_type_e PicoLoadMedia(const char *filename,
  163. const char *carthw_cfg_fname,
  164. const char *(*get_bios_filename)(int *region, const char *cd_fname),
  165. void (*do_region_override)(const char *media_filename))
  166. {
  167. const char *rom_fname = filename;
  168. enum media_type_e media_type;
  169. enum cd_track_type cd_img_type = CT_UNKNOWN;
  170. unsigned char *rom_data = NULL;
  171. unsigned int rom_size = 0;
  172. pm_file *rom = NULL;
  173. int cd_region = 0;
  174. int ret;
  175. media_type = detect_media(filename);
  176. if (media_type == PM_BAD_DETECT)
  177. goto out;
  178. if ((PicoIn.AHW & PAHW_MCD) && Pico_mcd != NULL)
  179. cdd_unload();
  180. PicoCartUnload();
  181. PicoIn.AHW = 0;
  182. PicoIn.quirks = 0;
  183. if (media_type == PM_CD)
  184. {
  185. // check for MegaCD image
  186. cd_img_type = PicoCdCheck(filename, &cd_region);
  187. if ((int)cd_img_type >= 0 && cd_img_type != CT_UNKNOWN)
  188. {
  189. // valid CD image, ask frontend for BIOS..
  190. rom_fname = NULL;
  191. if (get_bios_filename != NULL)
  192. rom_fname = get_bios_filename(&cd_region, filename);
  193. if (rom_fname == NULL) {
  194. media_type = PM_BAD_CD_NO_BIOS;
  195. goto out;
  196. }
  197. PicoIn.AHW |= PAHW_MCD;
  198. }
  199. else {
  200. media_type = PM_BAD_CD;
  201. goto out;
  202. }
  203. }
  204. else if (media_type == PM_MARK3) {
  205. lprintf("detected SMS ROM\n");
  206. PicoIn.AHW = PAHW_SMS;
  207. }
  208. rom = pm_open(rom_fname);
  209. if (rom == NULL) {
  210. lprintf("Failed to open ROM\n");
  211. media_type = PM_ERROR;
  212. goto out;
  213. }
  214. ret = PicoCartLoad(rom, &rom_data, &rom_size, (PicoIn.AHW & PAHW_SMS) ? 1 : 0);
  215. pm_close(rom);
  216. if (ret != 0) {
  217. if (ret == 2) lprintf("Out of memory\n");
  218. else if (ret == 3) lprintf("Read failed\n");
  219. else lprintf("PicoCartLoad() failed.\n");
  220. media_type = PM_ERROR;
  221. goto out;
  222. }
  223. // detect wrong files
  224. if (strncmp((char *)rom_data, "Pico", 4) == 0) {
  225. lprintf("savestate selected?\n");
  226. media_type = PM_BAD_DETECT;
  227. goto out;
  228. }
  229. if (!(PicoIn.AHW & PAHW_SMS)) {
  230. unsigned short *d = (unsigned short *)(rom_data + 4);
  231. if ((((d[0] << 16) | d[1]) & 0xffffff) >= (int)rom_size) {
  232. lprintf("bad reset vector\n");
  233. media_type = PM_BAD_DETECT;
  234. goto out;
  235. }
  236. }
  237. // load config for this ROM (do this before insert to get correct region)
  238. if (!(PicoIn.AHW & PAHW_MCD)) {
  239. memcpy(media_id_header, rom_data + 0x100, sizeof(media_id_header));
  240. if (do_region_override != NULL)
  241. do_region_override(filename);
  242. }
  243. if (PicoCartInsert(rom_data, rom_size, carthw_cfg_fname)) {
  244. media_type = PM_ERROR;
  245. goto out;
  246. }
  247. rom_data = NULL; // now belongs to PicoCart
  248. Pico.m.ncart_in = 0;
  249. // insert CD if it was detected
  250. if (cd_img_type != CT_UNKNOWN) {
  251. ret = cdd_load(filename, cd_img_type);
  252. if (ret != 0) {
  253. PicoCartUnload();
  254. media_type = PM_BAD_CD;
  255. goto out;
  256. }
  257. Pico.m.ncart_in = 1;
  258. }
  259. if (PicoIn.quirks & PQUIRK_FORCE_6BTN)
  260. PicoSetInputDevice(0, PICO_INPUT_PAD_6BTN);
  261. out:
  262. if (rom_data)
  263. free(rom_data);
  264. return media_type;
  265. }
  266. // vim:shiftwidth=2:ts=2:expandtab