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1 | \r |
4abeeb4b |
2 | // This file is part of the PicoDrive Megadrive Emulator\r |
3 | \r |
c41b9b97 |
4 | // Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r |
5 | \r |
4abeeb4b |
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 |
15eb0001 |
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 |