Initial support for Genesis/Megadrive PBC mode. VDP still needs Mode 4 to be useful.

1 files changed, 19 insertions, 2 deletions

diff --git a/system.c b/system.c
index 5d5e9f8..cef8575 100644
--- a/system.c
+++ b/system.c
@@ -1,14 +1,27 @@
 #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(uint8_t *rom, long filesize)
 {
-	if (filesize >= 0x104 && !memcmp("SEGA", rom + 0x100, 4)) {
+	if (safe_cmp("SEGA", 0x100, rom, filesize)) {
 		//TODO: Differentiate between vanilla Genesis and Sega CD/32X games
 		return SYSTEM_GENESIS;
 	}
-	//TODO: Detect SMS and Jaguar ROMs here
+	if (safe_cmp("TMR SEGA", 0x1FF0, rom, filesize) 
+		|| safe_cmp("TMR SEGA", 0x3FF0, rom, filesize) 
+		|| safe_cmp("TMR SEGA", 0x7FF0, rom, filesize) 
+	) {
+		return SYSTEM_SMS;
+	}
+	//TODO: Detect Jaguar ROMs here
 	
 	//More certain checks failed, look for a valid 68K reset vector
 	if (filesize >= 8) {
@@ -27,6 +40,10 @@ system_header *alloc_config_system(system_type stype, void *rom, uint32_t rom_si
 	{
 	case SYSTEM_GENESIS:
 		return &(alloc_config_genesis(rom, rom_size, lock_on, lock_on_size, opts, force_region, info_out))->header;
+#ifndef NO_Z80
+	case SYSTEM_SMS:
+		return &(alloc_configure_sms(rom, rom_size, lock_on, lock_on_size, opts, force_region, info_out))->header;
+#endif
 	default:
 		return NULL;
 	}