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comparison blastem.c @ 88:c339559f1d4f

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Forgot to add blastem main file earlier
author Mike Pavone <pavone@retrodev.com>
date Wed, 26 Dec 2012 21:50:48 -0800
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children 9757b4c6c33f
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87:60b5c9e2f4e0 88:c339559f1d4f
1 #include "68kinst.h"
2 #include "m68k_to_x86.h"
3 #include "mem.h"
4 #include "vdp.h"
5 #include "render.h"
6 #include "blastem.h"
7 #include <stdio.h>
8 #include <stdlib.h>
9
10 #define CARTRIDGE_WORDS 0x200000
11 #define RAM_WORDS 32 * 1024
12 #define MCLKS_PER_68K 7
13 //TODO: Figure out the exact value for this
14 #define MCLKS_PER_FRAME (MCLKS_LINE*262)
15 #define CYCLE_NEVER 0xFFFFFFFF
16
17 uint16_t cart[CARTRIDGE_WORDS];
18 uint16_t ram[RAM_WORDS];
19
20 io_port gamepad_1;
21 io_port gamepad_2;
22
23 #ifndef MIN
24 #define MIN(a,b) ((a) < (b) ? (a) : (b))
25 #endif
26
27 int load_rom(char * filename)
28 {
29 FILE * f = fopen(filename, "rb");
30 if (!f) {
31 return 0;
32 }
33 fseek(f, 0, SEEK_END);
34 long filesize = ftell(f);
35 fseek(f, 0, SEEK_SET);
36 fread(cart, 2, MIN(filesize/2, CARTRIDGE_WORDS), f);
37 fclose(f);
38 for(unsigned short * cur = cart; cur - cart < (filesize/2); ++cur)
39 {
40 *cur = (*cur >> 8) | (*cur << 8);
41 }
42 //TODO: Mirror ROM
43 return 1;
44 }
45
46 uint16_t read_dma_value(uint32_t address)
47 {
48 //addresses here are word addresses (i.e. bit 0 corresponds to A1), so no need to do div by 2
49 if (address < 0x200000) {
50 return cart[address];
51 } else if(address >= 0x700000) {
52 return ram[address & 0x7FFF];
53 }
54 //TODO: Figure out what happens when you try to DMA from weird adresses like IO or banked Z80 area
55 return 0;
56 }
57
58 #define VINT_CYCLE ((MCLKS_LINE * 226)/MCLKS_PER_68K)
59
60 m68k_context * sync_components(m68k_context * context)
61 {
62 //TODO: Handle sync targets smaller than a single frame
63 vdp_context * v_context = context->next_context;
64 uint32_t mclks = context->current_cycle * MCLKS_PER_68K;
65 if (mclks >= MCLKS_PER_FRAME) {
66 //printf("reached frame end | 68K Cycles: %d, MCLK Cycles: %d\n", context->current_cycle, mclks);
67 vdp_run_context(v_context, MCLKS_PER_FRAME);
68 wait_render_frame(v_context);
69 mclks -= MCLKS_PER_FRAME;
70 vdp_adjust_cycles(v_context, MCLKS_PER_FRAME);
71 io_adjust_cycles(&gamepad_1, context->current_cycle, MCLKS_PER_FRAME/MCLKS_PER_68K);
72 io_adjust_cycles(&gamepad_2, context->current_cycle, MCLKS_PER_FRAME/MCLKS_PER_68K);
73 context->current_cycle -= MCLKS_PER_FRAME/MCLKS_PER_68K;
74 if (mclks) {
75 vdp_run_context(v_context, mclks);
76 }
77 if (v_context->regs[REG_MODE_2] & 0x20 && ((context->status & 0x7) < 6)) {
78 if (context->int_cycle > VINT_CYCLE) {
79 context->int_cycle = VINT_CYCLE;
80 context->int_num = 6;
81 if (context->int_cycle < context->sync_cycle) {
82 context->target_cycle = context->int_cycle;
83 }
84 }
85 } else {
86 context->int_cycle = 0xFFFFFFFF;
87 context->target_cycle = context->sync_cycle;
88 }
89 } else {
90 //printf("running VDP for %d cycles\n", mclks - v_context->cycles);
91 vdp_run_context(v_context, mclks);
92 if (v_context->regs[REG_MODE_2] & 0x20 && ((context->status & 0x7) < 6)) {
93 if (context->int_cycle > VINT_CYCLE) {
94 context->int_cycle = VINT_CYCLE;
95 context->int_num = 6;
96 if (context->int_cycle < context->sync_cycle && context->int_cycle < context->current_cycle) {
97 context->target_cycle = context->int_cycle;
98 }
99 }
100 if (context->int_cycle <= context->current_cycle) {
101 context->int_cycle = CYCLE_NEVER;
102 context->target_cycle = context->sync_cycle;
103 }
104 } else {
105 context->int_cycle = CYCLE_NEVER;
106 context->target_cycle = context->sync_cycle;
107 }
108 }
109 return context;
110 }
111
112 m68k_context * vdp_port_write(uint32_t vdp_port, m68k_context * context, uint16_t value)
113 {
114 //printf("vdp_port write: %X, value: %X, cycle: %d\n", vdp_port, value, context->current_cycle);
115 sync_components(context);
116 vdp_context * v_context = context->next_context;
117 if (vdp_port < 0x10) {
118 if (vdp_port < 4) {
119 vdp_data_port_write(v_context, value);
120 } else if(vdp_port < 8) {
121 int blocked = vdp_control_port_write(v_context, value);
122 if (blocked) {
123 while(v_context->flags & FLAG_DMA_RUN) {
124 vdp_run_dma_done(v_context, MCLKS_PER_FRAME);
125 if (v_context->cycles >= MCLKS_PER_FRAME) {
126 wait_render_frame(v_context);
127 vdp_adjust_cycles(v_context, MCLKS_PER_FRAME);
128 io_adjust_cycles(&gamepad_1, v_context->cycles/MCLKS_PER_68K, MCLKS_PER_FRAME/MCLKS_PER_68K);
129 io_adjust_cycles(&gamepad_2, v_context->cycles/MCLKS_PER_68K, MCLKS_PER_FRAME/MCLKS_PER_68K);
130 }
131 }
132 context->current_cycle = v_context->cycles / MCLKS_PER_68K;
133 } else {
134 if (v_context->regs[REG_MODE_2] & 0x20 && ((context->status & 0x7) < 6)) {
135 if (context->int_cycle > VINT_CYCLE) {
136 context->int_cycle = VINT_CYCLE;
137 context->int_num = 6;
138 if (context->int_cycle < context->sync_cycle) {
139 context->target_cycle = context->int_cycle;
140 }
141 }
142 } else {
143 context->int_cycle = 0xFFFFFFFF;
144 context->target_cycle = context->sync_cycle;
145 }
146 }
147 } else {
148 printf("Illegal write to HV Counter port %X\n", vdp_port);
149 exit(1);
150 }
151 context->current_cycle = v_context->cycles/MCLKS_PER_68K;
152 } else if (vdp_port < 0x18) {
153 //TODO: Implement PSG
154 } else {
155 //TODO: Implement undocumented test register(s)
156 }
157 return context;
158 }
159
160 m68k_context * vdp_port_read(uint32_t vdp_port, m68k_context * context)
161 {
162 sync_components(context);
163 vdp_context * v_context = context->next_context;
164 if (vdp_port < 0x10) {
165 if (vdp_port < 4) {
166 context->value = vdp_data_port_read(v_context);
167 } else if(vdp_port < 8) {
168 context->value = vdp_control_port_read(v_context);
169 } else {
170 //TODO: Implement H/V counter
171 context->value = 0;
172 }
173 context->current_cycle = v_context->cycles/MCLKS_PER_68K;
174 } else {
175 printf("Illegal read from PSG or test register port %X\n", vdp_port);
176 exit(1);
177 }
178 return context;
179 }
180
181 #define TH 0x40
182 #define TH_TIMEOUT 8000
183 #define Z80_ACK_DELAY 3 //TODO: Calculate this on the fly based on how synced up the Z80 and 68K clocks are
184
185 uint8_t reset = 1;
186 uint8_t busreq = 0;
187 uint8_t busack = 0;
188 uint32_t busack_cycle = CYCLE_NEVER;
189 uint8_t new_busack = 0;
190
191 void io_adjust_cycles(io_port * pad, uint32_t current_cycle, uint32_t deduction)
192 {
193 uint8_t control = pad->control | 0x80;
194 uint8_t th = control & pad->output;
195 if (pad->input[GAMEPAD_TH0] || pad->input[GAMEPAD_TH1]) {
196 printf("adjust_cycles | control: %X, TH: %X, GAMEPAD_TH0: %X, GAMEPAD_TH1: %X, TH Counter: %d, Timeout: %d, Cycle: %d\n", control, th, pad->input[GAMEPAD_TH0], pad->input[GAMEPAD_TH1], pad->th_counter,pad->timeout_cycle, current_cycle);
197 }
198 if (current_cycle >= pad->timeout_cycle) {
199 pad->th_counter = 0;
200 } else {
201 pad->timeout_cycle -= deduction;
202 }
203 if (busack_cycle < CYCLE_NEVER && current_cycle < busack_cycle) {
204 busack_cycle -= deduction;
205 }
206 }
207
208 void io_data_write(io_port * pad, m68k_context * context, uint8_t value)
209 {
210 if (pad->control & TH) {
211 //check if TH has changed
212 if ((pad->output & TH) ^ (value & TH)) {
213 if (context->current_cycle >= pad->timeout_cycle) {
214 pad->th_counter = 0;
215 }
216 if (!(value & TH)) {
217 pad->th_counter++;
218 }
219 pad->timeout_cycle = context->current_cycle + TH_TIMEOUT;
220 }
221 }
222 pad->output = value;
223 }
224
225 void io_data_read(io_port * pad, m68k_context * context)
226 {
227 uint8_t control = pad->control | 0x80;
228 uint8_t th = control & pad->output;
229 uint8_t input;
230 if (context->current_cycle >= pad->timeout_cycle) {
231 pad->th_counter = 0;
232 }
233 if (pad->input[GAMEPAD_TH0] || pad->input[GAMEPAD_TH1]) {
234 printf("io_data_read | control: %X, TH: %X, GAMEPAD_TH0: %X, GAMEPAD_TH1: %X, TH Counter: %d, Timeout: %d, Cycle: %d\n", control, th, pad->input[GAMEPAD_TH0], pad->input[GAMEPAD_TH1], pad->th_counter,pad->timeout_cycle, context->current_cycle);
235 }
236 if (th) {
237 if (pad->th_counter == 2) {
238 input = pad->input[GAMEPAD_EXTRA];
239 } else {
240 input = pad->input[GAMEPAD_TH1];
241 }
242 } else {
243 if (pad->th_counter == 2) {
244 input = pad->input[GAMEPAD_TH0] | 0xF;
245 } else if(pad->th_counter == 3) {
246 input = pad->input[GAMEPAD_TH0] & 0x30;
247 } else {
248 input = pad->input[GAMEPAD_TH0];
249 }
250 }
251 context->value = ((~input) & (~control)) | (pad->output & control);
252 /*if (pad->input[GAMEPAD_TH0] || pad->input[GAMEPAD_TH1]) {
253 printf ("value: %X\n", context->value);
254 }*/
255 }
256
257 m68k_context * io_write(uint32_t location, m68k_context * context, uint8_t value)
258 {
259 if (location < 0x100) {
260 switch(location/2)
261 {
262 case 0x1:
263 io_data_write(&gamepad_1, context, value);
264 break;
265 case 0x2:
266 io_data_write(&gamepad_2, context, value);
267 break;
268 case 0x3://PORT C Data
269 break;
270 case 0x4:
271 gamepad_1.control = value;
272 break;
273 case 0x5:
274 gamepad_2.control = value;
275 break;
276 }
277 } else {
278 if (location == 0x1100) {
279 if (busack_cycle > context->current_cycle) {
280 busack = new_busack;
281 busack_cycle = CYCLE_NEVER;
282 }
283 if (value & 1) {
284 busreq = 1;
285 if(!reset) {
286 busack_cycle = context->current_cycle + Z80_ACK_DELAY;
287 new_busack = 1;
288 }
289 } else {
290 busreq = 0;
291 busack_cycle = CYCLE_NEVER;
292 busack = 0;
293 }
294 } else if (location == 0x1200) {
295 if (value & 1) {
296 if (reset && busreq) {
297 new_busack = 1;
298 busack_cycle = context->current_cycle + Z80_ACK_DELAY;
299 }
300 reset = 0;
301 } else {
302 busack = 0;
303 reset = 1;
304 }
305 }
306 }
307 return context;
308 }
309
310 m68k_context * io_write_w(uint32_t location, m68k_context * context, uint16_t value)
311 {
312 if (location < 0x100) {
313 switch(location/2)
314 {
315 case 0x1:
316 io_data_write(&gamepad_1, context, value);
317 break;
318 case 0x2:
319 io_data_write(&gamepad_2, context, value);
320 break;
321 case 0x3://PORT C Data
322 break;
323 case 0x4:
324 gamepad_1.control = value;
325 break;
326 case 0x5:
327 gamepad_2.control = value;
328 break;
329 }
330 } else {
331 printf("IO Write of %X to %X\n", value, location);
332 if (location == 0x1100) {
333 if (busack_cycle > context->current_cycle) {
334 busack = new_busack;
335 busack_cycle = CYCLE_NEVER;
336 }
337 if (value & 0x100) {
338 busreq = 1;
339 if(!reset) {
340 busack_cycle = context->current_cycle + Z80_ACK_DELAY;
341 new_busack = 1;
342 }
343 } else {
344 busreq = 0;
345 busack_cycle = CYCLE_NEVER;
346 busack = 0;
347 }
348 } else if (location == 0x1200) {
349 if (value & 0x100) {
350 if (reset && busreq) {
351 new_busack = 1;
352 busack_cycle = context->current_cycle + Z80_ACK_DELAY;
353 }
354 reset = 0;
355 } else {
356 busack = 0;
357 reset = 1;
358 }
359 }
360 }
361 return context;
362 }
363
364 m68k_context * io_read(uint32_t location, m68k_context * context)
365 {
366 if (location < 0x100) {
367 switch(location/2)
368 {
369 case 0x0:
370 //version bits should be 0 for now since we're not emulating TMSS
371 //Not sure about the other bits
372 context->value = 0;
373 break;
374 case 0x1:
375 io_data_read(&gamepad_1, context);
376 break;
377 case 0x2:
378 io_data_read(&gamepad_2, context);
379 break;
380 case 0x3://PORT C Data
381 break;
382 case 0x4:
383 context->value = gamepad_1.control;
384 break;
385 case 0x5:
386 context->value = gamepad_2.control;
387 break;
388 }
389 } else {
390 if (location == 0x1100) {
391 if (busack_cycle > context->current_cycle) {
392 busack = new_busack;
393 busack_cycle = CYCLE_NEVER;
394 }
395 context->value = (!reset) && busack;
396 printf("Byte read of BUSREQ returned %d\n", context->value);
397 } else if (location == 0x1200) {
398 context->value = !reset;
399 } else {
400 printf("Byte read of unknown IO location: %X\n", location);
401 }
402 }
403 return context;
404 }
405
406 m68k_context * io_read_w(uint32_t location, m68k_context * context)
407 {
408 if (location < 0x100) {
409 switch(location/2)
410 {
411 case 0x0:
412 //version bits should be 0 for now since we're not emulating TMSS
413 //Not sure about the other bits
414 context->value = 0;
415 break;
416 case 0x1:
417 io_data_read(&gamepad_1, context);
418 break;
419 case 0x2:
420 io_data_read(&gamepad_2, context);
421 break;
422 case 0x3://PORT C Data
423 break;
424 case 0x4:
425 context->value = gamepad_1.control;
426 break;
427 case 0x5:
428 context->value = gamepad_2.control;
429 break;
430 case 0x6:
431 //PORT C Control
432 context->value = 0;
433 break;
434 }
435 context->value = context->value | (context->value << 8);
436 printf("Word read to %X returned %d\n", location, context->value);
437 } else {
438 if (location == 0x1100) {
439 if (busack_cycle > context->current_cycle) {
440 busack = new_busack;
441 busack_cycle = CYCLE_NEVER;
442 }
443 context->value = ((!reset) && busack) << 8;
444 printf("Word read of BUSREQ returned %d\n", context->value);
445 } else if (location == 0x1200) {
446 context->value = (!reset) << 8;
447 } else {
448 printf("Word read of unknown IO location: %X\n", location);
449 }
450 }
451 return context;
452 }
453
454 int main(int argc, char ** argv)
455 {
456 if (argc < 2) {
457 fputs("Usage: blastem FILENAME\n", stderr);
458 return 1;
459 }
460 if(!load_rom(argv[1])) {
461 fprintf(stderr, "Failed to open %s for reading\n", argv[1]);
462 return 1;
463 }
464 int width = 320;
465 int height = 240;
466 if (argc > 2) {
467 width = atoi(argv[2]);
468 if (argc > 3) {
469 height = atoi(argv[3]);
470 } else {
471 height = (width/320) * 240;
472 }
473 }
474 render_init(width, height);
475 size_t size = 1024 * 1024;
476 uint8_t * transbuf = alloc_code(&size);
477
478 x86_68k_options opts;
479 m68k_context context;
480 vdp_context v_context;
481
482 init_x86_68k_opts(&opts);
483 init_68k_context(&context, opts.native_code_map, &opts);
484 init_vdp_context(&v_context);
485 context.next_context = &v_context;
486 //cartridge ROM
487 context.mem_pointers[0] = cart;
488 context.target_cycle = context.sync_cycle = MCLKS_PER_FRAME/MCLKS_PER_68K;
489 //work RAM
490 context.mem_pointers[1] = ram;
491 uint32_t address;
492 address = cart[0x68/2] << 16 | cart[0x6A/2];
493 uint8_t * end = transbuf + size;
494 transbuf = translate_m68k_stream(transbuf, end, address, &context);
495 address = cart[0x70/2] << 16 | cart[0x72/2];
496 transbuf = translate_m68k_stream(transbuf, end, address, &context);
497 address = cart[0x78/2] << 16 | cart[0x7A/2];
498 transbuf = translate_m68k_stream(transbuf, end, address, &context);
499 address = cart[2] << 16 | cart[3];
500 translate_m68k_stream(transbuf, end, address, &context);
501 m68k_reset(&context);
502 return 0;
503 }