| 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 | typedef unsigned char u8;\r |
| 14 | typedef unsigned short u16;\r |
| 15 | typedef unsigned int u32;\r |
| 16 | \r |
| 17 | static int PicoMemBase(u32 pc)\r |
| 18 | {\r |
| 19 | int membase=0;\r |
| 20 | \r |
| 21 | if (pc<Pico.romsize)\r |
| 22 | {\r |
| 23 | membase=(int)Pico.rom; // Program Counter in Rom\r |
| 24 | }\r |
| 25 | else if ((pc&0xe00000)==0xe00000)\r |
| 26 | {\r |
| 27 | membase=(int)Pico.ram-(pc&0xff0000); // Program Counter in Ram\r |
| 28 | }\r |
| 29 | else\r |
| 30 | {\r |
| 31 | // Error - Program Counter is invalid\r |
| 32 | membase=(int)Pico.rom;\r |
| 33 | }\r |
| 34 | \r |
| 35 | return membase;\r |
| 36 | }\r |
| 37 | \r |
| 38 | #ifdef EMU_A68K\r |
| 39 | extern "C" u8 *OP_ROM=NULL,*OP_RAM=NULL;\r |
| 40 | \r |
| 41 | static void CPU_CALL PicoCheckPc(u32 pc)\r |
| 42 | {\r |
| 43 | OP_ROM=(u8 *)PicoMemBase(pc);\r |
| 44 | \r |
| 45 | // don't bother calling us back unless it's outside the 64k segment\r |
| 46 | M68000_regs.AsmBank=(pc>>16);\r |
| 47 | }\r |
| 48 | #endif\r |
| 49 | \r |
| 50 | #ifdef EMU_C68K\r |
| 51 | static u32 PicoCheckPc(u32 pc)\r |
| 52 | {\r |
| 53 | pc-=PicoCpu.membase; // Get real pc\r |
| 54 | pc&=0xffffff;\r |
| 55 | \r |
| 56 | PicoCpu.membase=PicoMemBase(pc);\r |
| 57 | \r |
| 58 | return PicoCpu.membase+pc;\r |
| 59 | }\r |
| 60 | #endif\r |
| 61 | \r |
| 62 | #ifdef EMU_NULL\r |
| 63 | static u32 PicoCheckPc(u32) { return 0; }\r |
| 64 | #endif\r |
| 65 | \r |
| 66 | \r |
| 67 | int PicoInitPc(u32 pc)\r |
| 68 | {\r |
| 69 | PicoCheckPc(pc);\r |
| 70 | return 0;\r |
| 71 | }\r |
| 72 | \r |
| 73 | // -----------------------------------------------------------------\r |
| 74 | static int PadRead(int i)\r |
| 75 | {\r |
| 76 | int pad=0,value=0;\r |
| 77 | pad=~PicoPad[i]; // Get inverse of pad\r |
| 78 | \r |
| 79 | if (Pico.m.padSelect[i]) value=0x40|(pad&0x3f); // 01CB RLDU\r |
| 80 | else value=((pad&0xc0)>>2)|(pad&3); // 00SA 00DU\r |
| 81 | \r |
| 82 | return (value<<8)|value; // Mirror bytes\r |
| 83 | }\r |
| 84 | \r |
| 85 | static u32 OtherRead16(u32 a)\r |
| 86 | {\r |
| 87 | u32 d=0;\r |
| 88 | \r |
| 89 | if ((a&0xffe000)==0xa00000)\r |
| 90 | {\r |
| 91 | // Z80 ram\r |
| 92 | d=*(u16 *)(Pico.zram+(a&0x1fff));\r |
| 93 | \r |
| 94 | if (Pico.m.rotate&2) { d=(Pico.m.rotate>>2)&0xff; d|=d<<8; } // Fake z80\r |
| 95 | Pico.m.rotate++;\r |
| 96 | \r |
| 97 | goto end;\r |
| 98 | }\r |
| 99 | \r |
| 100 | if ((a&0xffe000)==0xa00000)\r |
| 101 | {\r |
| 102 | // Fake Z80 ram\r |
| 103 | d=((Pico.m.rotate++)>>2)&0xff; d|=d<<8;\r |
| 104 | goto end;\r |
| 105 | }\r |
| 106 | \r |
| 107 | if (a==0xa04000) { d=Pico.m.rotate&3; Pico.m.rotate++; goto end; } // Fudge\r |
| 108 | if (a==0xa10000) { d=Pico.m.hardware; goto end; } // Hardware value\r |
| 109 | if (a==0xa10002) { d=PadRead(0); goto end; }\r |
| 110 | if (a==0xa10004) { d=PadRead(1); goto end; }\r |
| 111 | if (a==0xa11100) { d=((Pico.m.rotate++)&4)<<6; goto end; } // Fudge z80 reset\r |
| 112 | \r |
| 113 | if ((a&0xffffe0)==0xc00000) { d=PicoVideoRead(a); goto end; }\r |
| 114 | \r |
| 115 | end:\r |
| 116 | return d;\r |
| 117 | }\r |
| 118 | \r |
| 119 | static void OtherWrite8(u32 a,u32 d)\r |
| 120 | {\r |
| 121 | if ((a&0xffe000)==0xa00000) { Pico.zram[(a^1)&0x1fff]=(u8)d; return; } // Z80 ram\r |
| 122 | if ((a&0xfffffc)==0xa04000) { PsndFm(a,d); return; } // FM Sound\r |
| 123 | \r |
| 124 | if (a==0xa11100) { Pico.m.z80Run=(u8)(d^1); return; }\r |
| 125 | if (a==0xa10003) { Pico.m.padSelect[0]=(u8)((d>>6)&1); return; } // Joypad 1 select\r |
| 126 | if (a==0xa10005) { Pico.m.padSelect[1]=(u8)((d>>6)&1); return; } // Joypad 2 select\r |
| 127 | \r |
| 128 | if ((a&0xffffe0)==0xc00000) { PicoVideoWrite(a,d|(d<<8)); return; } // Byte access gets mirrored\r |
| 129 | }\r |
| 130 | \r |
| 131 | static void OtherWrite16(u32 a,u32 d)\r |
| 132 | {\r |
| 133 | if ((a&0xffffe0)==0xc00000) { PicoVideoWrite(a,d); return; }\r |
| 134 | if ((a&0xffe000)==0xa00000) { *(u16 *)(Pico.zram+(a&0x1ffe))=(u16)d; return; } // Z80 ram\r |
| 135 | \r |
| 136 | OtherWrite8(a, d>>8);\r |
| 137 | OtherWrite8(a+1,d&0xff);\r |
| 138 | }\r |
| 139 | \r |
| 140 | // -----------------------------------------------------------------\r |
| 141 | // Read Rom and read Ram\r |
| 142 | \r |
| 143 | static u8 CPU_CALL PicoRead8(u32 a)\r |
| 144 | {\r |
| 145 | u32 d=0;\r |
| 146 | a&=0xffffff;\r |
| 147 | \r |
| 148 | if (a<Pico.romsize) return *(u8 *)(Pico.rom+(a^1)); // Rom\r |
| 149 | if ((a&0xe00000)==0xe00000) return *(u8 *)(Pico.ram+((a^1)&0xffff)); // Ram\r |
| 150 | \r |
| 151 | d=OtherRead16(a&~1); if ((a&1)==0) d>>=8;\r |
| 152 | return (u8)d;\r |
| 153 | }\r |
| 154 | \r |
| 155 | u16 CPU_CALL PicoRead16(u32 a)\r |
| 156 | {\r |
| 157 | a&=0xfffffe;\r |
| 158 | \r |
| 159 | if (a<Pico.romsize) { u16 *pm=(u16 *)(Pico.rom+a); return pm[0]; } // Rom\r |
| 160 | if ((a&0xe00000)==0xe00000) { u16 *pm=(u16 *)(Pico.ram+(a&0xffff)); return pm[0]; } // Ram\r |
| 161 | \r |
| 162 | return (u16)OtherRead16(a);\r |
| 163 | }\r |
| 164 | \r |
| 165 | u32 CPU_CALL PicoRead32(u32 a)\r |
| 166 | {\r |
| 167 | a&=0xfffffe;\r |
| 168 | \r |
| 169 | if (a<Pico.romsize) { u16 *pm=(u16 *)(Pico.rom+a); return (pm[0]<<16)|pm[1]; } // Rom\r |
| 170 | if ((a&0xe00000)==0xe00000) { u16 *pm=(u16 *)(Pico.ram+(a&0xffff)); return (pm[0]<<16)|pm[1]; } // Ram\r |
| 171 | \r |
| 172 | return (OtherRead16(a)<<16)|OtherRead16(a+2);\r |
| 173 | }\r |
| 174 | \r |
| 175 | // -----------------------------------------------------------------\r |
| 176 | // Write Ram\r |
| 177 | \r |
| 178 | static void CPU_CALL PicoWrite8(u32 a,u8 d)\r |
| 179 | {\r |
| 180 | if ((a&0xe00000)==0xe00000) { u8 *pm=(u8 *)(Pico.ram+((a^1)&0xffff)); pm[0]=d; return; } // Ram\r |
| 181 | \r |
| 182 | a&=0xffffff;\r |
| 183 | OtherWrite8(a,d);\r |
| 184 | }\r |
| 185 | \r |
| 186 | static void CPU_CALL PicoWrite16(u32 a,u16 d)\r |
| 187 | {\r |
| 188 | if ((a&0xe00000)==0xe00000) { *(u16 *)(Pico.ram+(a&0xfffe))=d; return; } // Ram\r |
| 189 | \r |
| 190 | a&=0xfffffe;\r |
| 191 | OtherWrite16(a,d);\r |
| 192 | }\r |
| 193 | \r |
| 194 | static void CPU_CALL PicoWrite32(u32 a,u32 d)\r |
| 195 | {\r |
| 196 | if ((a&0xe00000)==0xe00000)\r |
| 197 | {\r |
| 198 | // Ram:\r |
| 199 | u16 *pm=(u16 *)(Pico.ram+(a&0xfffe));\r |
| 200 | pm[0]=(u16)(d>>16); pm[1]=(u16)d;\r |
| 201 | return;\r |
| 202 | }\r |
| 203 | \r |
| 204 | a&=0xfffffe;\r |
| 205 | OtherWrite16(a, (u16)(d>>16));\r |
| 206 | OtherWrite16(a+2,(u16)d);\r |
| 207 | }\r |
| 208 | \r |
| 209 | \r |
| 210 | // -----------------------------------------------------------------\r |
| 211 | int PicoMemInit()\r |
| 212 | {\r |
| 213 | #ifdef EMU_C68K\r |
| 214 | // Setup memory callbacks:\r |
| 215 | PicoCpu.checkpc=PicoCheckPc;\r |
| 216 | PicoCpu.fetch8 =PicoCpu.read8 =PicoRead8;\r |
| 217 | PicoCpu.fetch16=PicoCpu.read16=PicoRead16;\r |
| 218 | PicoCpu.fetch32=PicoCpu.read32=PicoRead32;\r |
| 219 | PicoCpu.write8 =PicoWrite8;\r |
| 220 | PicoCpu.write16=PicoWrite16;\r |
| 221 | PicoCpu.write32=PicoWrite32;\r |
| 222 | #endif\r |
| 223 | return 0;\r |
| 224 | }\r |
| 225 | \r |
| 226 | #ifdef EMU_A68K\r |
| 227 | struct A68KInter\r |
| 228 | {\r |
| 229 | u32 unknown;\r |
| 230 | u8 (__fastcall *Read8) (u32 a);\r |
| 231 | u16 (__fastcall *Read16)(u32 a);\r |
| 232 | u32 (__fastcall *Read32)(u32 a);\r |
| 233 | void (__fastcall *Write8) (u32 a,u8 d);\r |
| 234 | void (__fastcall *Write16) (u32 a,u16 d);\r |
| 235 | void (__fastcall *Write32) (u32 a,u32 d);\r |
| 236 | void (__fastcall *ChangePc)(u32 a);\r |
| 237 | u8 (__fastcall *PcRel8) (u32 a);\r |
| 238 | u16 (__fastcall *PcRel16)(u32 a);\r |
| 239 | u32 (__fastcall *PcRel32)(u32 a);\r |
| 240 | u16 (__fastcall *Dir16)(u32 a);\r |
| 241 | u32 (__fastcall *Dir32)(u32 a);\r |
| 242 | };\r |
| 243 | \r |
| 244 | extern "C" struct A68KInter a68k_memory_intf=\r |
| 245 | {\r |
| 246 | 0,\r |
| 247 | PicoRead8,\r |
| 248 | PicoRead16,\r |
| 249 | PicoRead32,\r |
| 250 | PicoWrite8,\r |
| 251 | PicoWrite16,\r |
| 252 | PicoWrite32,\r |
| 253 | PicoCheckPc,\r |
| 254 | PicoRead8,\r |
| 255 | PicoRead16,\r |
| 256 | PicoRead32,\r |
| 257 | PicoRead16, // unused\r |
| 258 | PicoRead32, // unused\r |
| 259 | };\r |
| 260 | #endif\r |