| 1 | \r |
| 2 | // This file is part of the PicoDrive Megadrive Emulator\r |
| 3 | \r |
| 4 | // Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r |
| 5 | \r |
| 6 | // This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r |
| 7 | // You can choose the license that has the most advantages for you.\r |
| 8 | \r |
| 9 | // SVN repository can be found at http://code.google.com/p/cyclone68000/\r |
| 10 | \r |
| 11 | #include "PicoInt.h"\r |
| 12 | \r |
| 13 | static void Byteswap(unsigned char *data,int len)\r |
| 14 | {\r |
| 15 | int i=0;\r |
| 16 | \r |
| 17 | if (len<2) return; // Too short\r |
| 18 | \r |
| 19 | do\r |
| 20 | {\r |
| 21 | unsigned short *pd=(unsigned short *)(data+i);\r |
| 22 | int value=*pd; // Get 2 bytes\r |
| 23 | \r |
| 24 | value=(value<<8)|(value>>8); // Byteswap it\r |
| 25 | *pd=(unsigned short)value; // Put 2b ytes\r |
| 26 | i+=2;\r |
| 27 | } \r |
| 28 | while (i+2<=len);\r |
| 29 | }\r |
| 30 | \r |
| 31 | // Interleve a 16k block and byteswap\r |
| 32 | static int InterleveBlock(unsigned char *dest,unsigned char *src)\r |
| 33 | {\r |
| 34 | int i=0;\r |
| 35 | for (i=0;i<0x2000;i++) dest[(i<<1) ]=src[ i]; // Odd\r |
| 36 | for (i=0;i<0x2000;i++) dest[(i<<1)+1]=src[0x2000+i]; // Even\r |
| 37 | return 0;\r |
| 38 | }\r |
| 39 | \r |
| 40 | // Decode a SMD file\r |
| 41 | static int DecodeSmd(unsigned char *data,int len)\r |
| 42 | {\r |
| 43 | unsigned char *temp=NULL;\r |
| 44 | int i=0;\r |
| 45 | \r |
| 46 | temp=(unsigned char *)malloc(0x4000);\r |
| 47 | if (temp==NULL) return 1;\r |
| 48 | memset(temp,0,0x4000);\r |
| 49 | \r |
| 50 | // Interleve each 16k block and shift down by 0x200:\r |
| 51 | for (i=0; i+0x4200<=len; i+=0x4000)\r |
| 52 | {\r |
| 53 | InterleveBlock(temp,data+0x200+i); // Interleve 16k to temporary buffer\r |
| 54 | memcpy(data+i,temp,0x4000); // Copy back in\r |
| 55 | }\r |
| 56 | \r |
| 57 | free(temp);\r |
| 58 | return 0;\r |
| 59 | }\r |
| 60 | \r |
| 61 | int PicoCartLoad(FILE *f,unsigned char **prom,unsigned int *psize)\r |
| 62 | {\r |
| 63 | unsigned char *rom=NULL; int size=0;\r |
| 64 | if (f==NULL) return 1;\r |
| 65 | \r |
| 66 | fseek(f,0,SEEK_END); size=ftell(f); fseek(f,0,SEEK_SET);\r |
| 67 | \r |
| 68 | size=(size+3)&~3; // Round up to a multiple of 4\r |
| 69 | \r |
| 70 | // Allocate space for the rom plus padding\r |
| 71 | rom=(unsigned char *)malloc(size+4);\r |
| 72 | if (rom==NULL) { fclose(f); return 1; }\r |
| 73 | memset(rom,0,size+4);\r |
| 74 | \r |
| 75 | fread(rom,1,size,f); // Load up the rom\r |
| 76 | fclose(f);\r |
| 77 | \r |
| 78 | // Check for SMD:\r |
| 79 | if ((size&0x3fff)==0x200) { DecodeSmd(rom,size); size-=0x200; } // Decode and byteswap SMD\r |
| 80 | else Byteswap(rom,size); // Just byteswap\r |
| 81 | \r |
| 82 | if (prom) *prom=rom;\r |
| 83 | if (psize) *psize=size;\r |
| 84 | \r |
| 85 | return 0;\r |
| 86 | }\r |
| 87 | \r |
| 88 | // Insert/remove a cartridge:\r |
| 89 | int PicoCartInsert(unsigned char *rom,unsigned int romsize)\r |
| 90 | {\r |
| 91 | // Make sure movie playing/recording is stopped:\r |
| 92 | if (PmovFile) fclose(PmovFile);\r |
| 93 | PmovFile=NULL; PmovAction=0;\r |
| 94 | \r |
| 95 | memset(&Pico,0,sizeof(Pico)); // Blank Pico state\r |
| 96 | Pico.rom=rom;\r |
| 97 | Pico.romsize=romsize;\r |
| 98 | PicoReset();\r |
| 99 | \r |
| 100 | return 0;\r |
| 101 | }\r |