15eb0001 |
1 | \r |
4abeeb4b |
2 | // This file is part of the PicoDrive Megadrive Emulator\r |
3 | \r |
4 | // This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r |
5 | // You can choose the license that has the most advantages for you.\r |
6 | \r |
7 | // SVN repository can be found at http://code.google.com/p/cyclone68000/\r |
8 | \r |
15eb0001 |
9 | #include "PicoInt.h"\r |
10 | \r |
11 | typedef unsigned char u8;\r |
12 | typedef unsigned short u16;\r |
13 | typedef unsigned int u32;\r |
14 | \r |
15 | static int PicoMemBase(u32 pc)\r |
16 | {\r |
17 | int membase=0;\r |
18 | \r |
19 | if (pc<Pico.romsize)\r |
20 | {\r |
21 | membase=(int)Pico.rom; // Program Counter in Rom\r |
22 | }\r |
23 | else if ((pc&0xe00000)==0xe00000)\r |
24 | {\r |
25 | membase=(int)Pico.ram-(pc&0xff0000); // Program Counter in Ram\r |
26 | }\r |
27 | else\r |
28 | {\r |
29 | // Error - Program Counter is invalid\r |
30 | membase=(int)Pico.rom;\r |
31 | }\r |
32 | \r |
33 | return membase;\r |
34 | }\r |
35 | \r |
36 | #ifdef EMU_A68K\r |
37 | extern "C" u8 *OP_ROM=NULL,*OP_RAM=NULL;\r |
38 | \r |
39 | static void CPU_CALL PicoCheckPc(u32 pc)\r |
40 | {\r |
41 | OP_ROM=(u8 *)PicoMemBase(pc);\r |
42 | \r |
43 | // don't bother calling us back unless it's outside the 64k segment\r |
44 | M68000_regs.AsmBank=(pc>>16);\r |
45 | }\r |
46 | #endif\r |
47 | \r |
48 | #ifdef EMU_C68K\r |
49 | static u32 PicoCheckPc(u32 pc)\r |
50 | {\r |
51 | pc-=PicoCpu.membase; // Get real pc\r |
52 | pc&=0xffffff;\r |
53 | \r |
54 | PicoCpu.membase=PicoMemBase(pc);\r |
55 | \r |
56 | return PicoCpu.membase+pc;\r |
57 | }\r |
58 | #endif\r |
59 | \r |
60 | #ifdef EMU_NULL\r |
61 | static u32 PicoCheckPc(u32) { return 0; }\r |
62 | #endif\r |
63 | \r |
64 | \r |
65 | int PicoInitPc(u32 pc)\r |
66 | {\r |
67 | PicoCheckPc(pc);\r |
68 | return 0;\r |
69 | }\r |
70 | \r |
71 | // -----------------------------------------------------------------\r |
72 | static int PadRead(int i)\r |
73 | {\r |
74 | int pad=0,value=0;\r |
75 | pad=~PicoPad[i]; // Get inverse of pad\r |
76 | \r |
77 | if (Pico.m.padSelect[i]) value=0x40|(pad&0x3f); // 01CB RLDU\r |
78 | else value=((pad&0xc0)>>2)|(pad&3); // 00SA 00DU\r |
79 | \r |
80 | return (value<<8)|value; // Mirror bytes\r |
81 | }\r |
82 | \r |
83 | static u32 OtherRead16(u32 a)\r |
84 | {\r |
85 | u32 d=0;\r |
86 | \r |
87 | if ((a&0xffe000)==0xa00000)\r |
88 | {\r |
89 | // Z80 ram\r |
90 | d=*(u16 *)(Pico.zram+(a&0x1fff));\r |
91 | \r |
92 | if (Pico.m.rotate&2) { d=(Pico.m.rotate>>2)&0xff; d|=d<<8; } // Fake z80\r |
93 | Pico.m.rotate++;\r |
94 | \r |
95 | goto end;\r |
96 | }\r |
97 | \r |
98 | if ((a&0xffe000)==0xa00000)\r |
99 | {\r |
100 | // Fake Z80 ram\r |
101 | d=((Pico.m.rotate++)>>2)&0xff; d|=d<<8;\r |
102 | goto end;\r |
103 | }\r |
104 | \r |
105 | if (a==0xa04000) { d=Pico.m.rotate&3; Pico.m.rotate++; goto end; } // Fudge\r |
106 | if (a==0xa10000) { d=Pico.m.hardware; goto end; } // Hardware value\r |
107 | if (a==0xa10002) { d=PadRead(0); goto end; }\r |
108 | if (a==0xa10004) { d=PadRead(1); goto end; }\r |
109 | if (a==0xa11100) { d=((Pico.m.rotate++)&4)<<6; goto end; } // Fudge z80 reset\r |
110 | \r |
111 | if ((a&0xffffe0)==0xc00000) { d=PicoVideoRead(a); goto end; }\r |
112 | \r |
113 | end:\r |
114 | return d;\r |
115 | }\r |
116 | \r |
117 | static void OtherWrite8(u32 a,u32 d)\r |
118 | {\r |
119 | if ((a&0xffe000)==0xa00000) { Pico.zram[(a^1)&0x1fff]=(u8)d; return; } // Z80 ram\r |
120 | if ((a&0xfffffc)==0xa04000) { PsndFm(a,d); return; } // FM Sound\r |
121 | \r |
122 | if (a==0xa11100) { Pico.m.z80Run=(u8)(d^1); return; }\r |
123 | if (a==0xa10003) { Pico.m.padSelect[0]=(u8)((d>>6)&1); return; } // Joypad 1 select\r |
124 | if (a==0xa10005) { Pico.m.padSelect[1]=(u8)((d>>6)&1); return; } // Joypad 2 select\r |
125 | \r |
126 | if ((a&0xffffe0)==0xc00000) { PicoVideoWrite(a,d|(d<<8)); return; } // Byte access gets mirrored\r |
127 | }\r |
128 | \r |
129 | static void OtherWrite16(u32 a,u32 d)\r |
130 | {\r |
131 | if ((a&0xffffe0)==0xc00000) { PicoVideoWrite(a,d); return; }\r |
132 | if ((a&0xffe000)==0xa00000) { *(u16 *)(Pico.zram+(a&0x1ffe))=(u16)d; return; } // Z80 ram\r |
133 | \r |
134 | OtherWrite8(a, d>>8);\r |
135 | OtherWrite8(a+1,d&0xff);\r |
136 | }\r |
137 | \r |
138 | // -----------------------------------------------------------------\r |
139 | // Read Rom and read Ram\r |
140 | \r |
141 | static u8 CPU_CALL PicoRead8(u32 a)\r |
142 | {\r |
143 | u32 d=0;\r |
144 | a&=0xffffff;\r |
145 | \r |
146 | if (a<Pico.romsize) return *(u8 *)(Pico.rom+(a^1)); // Rom\r |
147 | if ((a&0xe00000)==0xe00000) return *(u8 *)(Pico.ram+((a^1)&0xffff)); // Ram\r |
148 | \r |
149 | d=OtherRead16(a&~1); if ((a&1)==0) d>>=8;\r |
150 | return (u8)d;\r |
151 | }\r |
152 | \r |
153 | u16 CPU_CALL PicoRead16(u32 a)\r |
154 | {\r |
155 | a&=0xfffffe;\r |
156 | \r |
157 | if (a<Pico.romsize) { u16 *pm=(u16 *)(Pico.rom+a); return pm[0]; } // Rom\r |
158 | if ((a&0xe00000)==0xe00000) { u16 *pm=(u16 *)(Pico.ram+(a&0xffff)); return pm[0]; } // Ram\r |
159 | \r |
160 | return (u16)OtherRead16(a);\r |
161 | }\r |
162 | \r |
163 | u32 CPU_CALL PicoRead32(u32 a)\r |
164 | {\r |
165 | a&=0xfffffe;\r |
166 | \r |
167 | if (a<Pico.romsize) { u16 *pm=(u16 *)(Pico.rom+a); return (pm[0]<<16)|pm[1]; } // Rom\r |
168 | if ((a&0xe00000)==0xe00000) { u16 *pm=(u16 *)(Pico.ram+(a&0xffff)); return (pm[0]<<16)|pm[1]; } // Ram\r |
169 | \r |
170 | return (OtherRead16(a)<<16)|OtherRead16(a+2);\r |
171 | }\r |
172 | \r |
173 | // -----------------------------------------------------------------\r |
174 | // Write Ram\r |
175 | \r |
176 | static void CPU_CALL PicoWrite8(u32 a,u8 d)\r |
177 | {\r |
178 | if ((a&0xe00000)==0xe00000) { u8 *pm=(u8 *)(Pico.ram+((a^1)&0xffff)); pm[0]=d; return; } // Ram\r |
179 | \r |
180 | a&=0xffffff;\r |
181 | OtherWrite8(a,d);\r |
182 | }\r |
183 | \r |
184 | static void CPU_CALL PicoWrite16(u32 a,u16 d)\r |
185 | {\r |
186 | if ((a&0xe00000)==0xe00000) { *(u16 *)(Pico.ram+(a&0xfffe))=d; return; } // Ram\r |
187 | \r |
188 | a&=0xfffffe;\r |
189 | OtherWrite16(a,d);\r |
190 | }\r |
191 | \r |
192 | static void CPU_CALL PicoWrite32(u32 a,u32 d)\r |
193 | {\r |
194 | if ((a&0xe00000)==0xe00000)\r |
195 | {\r |
196 | // Ram:\r |
197 | u16 *pm=(u16 *)(Pico.ram+(a&0xfffe));\r |
198 | pm[0]=(u16)(d>>16); pm[1]=(u16)d;\r |
199 | return;\r |
200 | }\r |
201 | \r |
202 | a&=0xfffffe;\r |
203 | OtherWrite16(a, (u16)(d>>16));\r |
204 | OtherWrite16(a+2,(u16)d);\r |
205 | }\r |
206 | \r |
207 | \r |
208 | // -----------------------------------------------------------------\r |
209 | int PicoMemInit()\r |
210 | {\r |
211 | #ifdef EMU_C68K\r |
212 | // Setup memory callbacks:\r |
213 | PicoCpu.checkpc=PicoCheckPc;\r |
214 | PicoCpu.fetch8 =PicoCpu.read8 =PicoRead8;\r |
215 | PicoCpu.fetch16=PicoCpu.read16=PicoRead16;\r |
216 | PicoCpu.fetch32=PicoCpu.read32=PicoRead32;\r |
217 | PicoCpu.write8 =PicoWrite8;\r |
218 | PicoCpu.write16=PicoWrite16;\r |
219 | PicoCpu.write32=PicoWrite32;\r |
220 | #endif\r |
221 | return 0;\r |
222 | }\r |
223 | \r |
224 | #ifdef EMU_A68K\r |
225 | struct A68KInter\r |
226 | {\r |
227 | u32 unknown;\r |
228 | u8 (__fastcall *Read8) (u32 a);\r |
229 | u16 (__fastcall *Read16)(u32 a);\r |
230 | u32 (__fastcall *Read32)(u32 a);\r |
231 | void (__fastcall *Write8) (u32 a,u8 d);\r |
232 | void (__fastcall *Write16) (u32 a,u16 d);\r |
233 | void (__fastcall *Write32) (u32 a,u32 d);\r |
234 | void (__fastcall *ChangePc)(u32 a);\r |
235 | u8 (__fastcall *PcRel8) (u32 a);\r |
236 | u16 (__fastcall *PcRel16)(u32 a);\r |
237 | u32 (__fastcall *PcRel32)(u32 a);\r |
238 | u16 (__fastcall *Dir16)(u32 a);\r |
239 | u32 (__fastcall *Dir32)(u32 a);\r |
240 | };\r |
241 | \r |
242 | extern "C" struct A68KInter a68k_memory_intf=\r |
243 | {\r |
244 | 0,\r |
245 | PicoRead8,\r |
246 | PicoRead16,\r |
247 | PicoRead32,\r |
248 | PicoWrite8,\r |
249 | PicoWrite16,\r |
250 | PicoWrite32,\r |
251 | PicoCheckPc,\r |
252 | PicoRead8,\r |
253 | PicoRead16,\r |
254 | PicoRead32,\r |
255 | PicoRead16, // unused\r |
256 | PicoRead32, // unused\r |
257 | };\r |
258 | #endif\r |