Mercurial > repos > blastem
view system.c @ 1337:d092c15246a3
Initial stab at horizontal border when VDP test register layer selection is in effect for H40. Extended horizontal borders in Titancade scene and ninja escape scene mostly correct now
author | Michael Pavone <pavone@retrodev.com> |
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date | Sat, 29 Apr 2017 16:51:57 -0700 |
parents | aee2177a1630 |
children | a763523dadf4 360d5bab199f |
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#include <string.h> #include "system.h" #include "genesis.h" #include "sms.h" uint8_t safe_cmp(char *str, long offset, uint8_t *buffer, long filesize) { long len = strlen(str); return filesize >= offset+len && !memcmp(str, buffer + offset, len); } system_type detect_system_type(system_media *media) { if (safe_cmp("SEGA", 0x100, media->buffer, media->size)) { //TODO: Differentiate between vanilla Genesis and Sega CD/32X games return SYSTEM_GENESIS; } if (safe_cmp("TMR SEGA", 0x1FF0, media->buffer, media->size) || safe_cmp("TMR SEGA", 0x3FF0, media->buffer, media->size) || safe_cmp("TMR SEGA", 0x7FF0, media->buffer, media->size) ) { return SYSTEM_SMS; } //TODO: Detect Jaguar ROMs here //Header based detection failed, examine filename for clues if (media->extension) { if (!strcmp("md", media->extension) || !strcmp("gen", media->extension)) { return SYSTEM_GENESIS; } if (!strcmp("sms", media->extension)) { return SYSTEM_SMS; } if (!strcmp("j64", media->extension)) { return SYSTEM_JAGUAR; } } //More certain checks failed, look for a valid 68K reset vector if (media->size >= 8) { char *rom = media->buffer; uint32_t reset = rom[4] << 24 | rom[5] << 16 | rom[6] << 8 | rom[7]; if (!(reset & 1) && reset < media->size) { //we have a valid looking reset vector, assume it's a Genesis ROM return SYSTEM_GENESIS; } } return SYSTEM_UNKNOWN; } system_header *alloc_config_system(system_type stype, system_media *media, uint32_t opts, uint8_t force_region, rom_info *info_out) { void *lock_on = NULL; uint32_t lock_on_size = 0; if (media->chain) { lock_on = media->chain->buffer; lock_on_size = media->chain->size; } switch (stype) { case SYSTEM_GENESIS: return &(alloc_config_genesis(media->buffer, media->size, lock_on, lock_on_size, opts, force_region, info_out))->header; #ifndef NO_Z80 case SYSTEM_SMS: return &(alloc_configure_sms(media, opts, force_region, info_out))->header; #endif default: return NULL; } }