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comparison system.c @ 1111:2eb54e24914e

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Mostly working changes to allow support for multiple emulated system types in main blastem program
author Michael Pavone <pavone@retrodev.com>
date Mon, 19 Dec 2016 13:28:18 -0800
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children 928a65750345
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1110:d1eed3b1121c 1111:2eb54e24914e
1 #include <string.h>
2 #include "system.h"
3 #include "genesis.h"
4
5 system_type detect_system_type(uint8_t *rom, long filesize)
6 {
7 if (filesize >= 0x104 && !memcmp("SEGA", rom + 0x100, 4)) {
8 //TODO: Differentiate between vanilla Genesis and Sega CD/32X games
9 return SYSTEM_GENESIS;
10 }
11 //TODO: Detect SMS and Jaguar ROMs here
12
13 //More certain checks failed, look for a valid 68K reset vector
14 if (filesize >= 8) {
15 uint32_t reset = rom[4] << 24 | rom[5] << 16 | rom[6] << 8 | rom[7];
16 if (!(reset & 1) && reset < filesize) {
17 //we have a valid looking reset vector, assume it's a Genesis ROM
18 return SYSTEM_GENESIS;
19 }
20 }
21 return SYSTEM_UNKNOWN;
22 }
23
24 system_header *alloc_config_system(system_type stype, void *rom, uint32_t rom_size, void *lock_on, uint32_t lock_on_size, uint32_t opts, uint8_t force_region, rom_info *info_out)
25 {
26 switch (stype)
27 {
28 case SYSTEM_GENESIS:
29 return &(alloc_config_genesis(rom, rom_size, lock_on, lock_on_size, opts, force_region, info_out))->header;
30 default:
31 return NULL;
32 }
33 }