Mercurial > repos > blastem
view system.c @ 1637:95880d947257
Fix for VRAM byte write order broke VDP FIFO testing ROM results. This change cleans up VRAM writes and fixes the regression while preserving the correct VRAM byte write order
author | Michael Pavone <pavone@retrodev.com> |
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date | Sun, 11 Nov 2018 22:39:29 -0800 |
parents | 360d5bab199f |
children | 5dacaef602a7 7b62e6805e6a |
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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) { 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))->header; #ifndef NO_Z80 case SYSTEM_SMS: return &(alloc_configure_sms(media, opts, force_region))->header; #endif default: return NULL; } }