main.c

   1 /* gameplaySP
   2  *
   3  * Copyright (C) 2006 Exophase <exophase@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of
   8  * the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include "common.h"
  21
  22 #ifdef PSP_BUILD
  23
  24 //PSP_MODULE_INFO("gpSP", 0x1000, 0, 6);
  25 //PSP_MAIN_THREAD_ATTR(THREAD_ATTR_USER);
  26
  27 void vblank_interrupt_handler(u32 sub, u32 *parg);
  28
  29 #endif
  30
  31 timer_type timer[4];
  32
  33 //debug_state current_debug_state = COUNTDOWN_BREAKPOINT;
  34 //debug_state current_debug_state = PC_BREAKPOINT;
  35 u32 breakpoint_value = 0x7c5000;
  36 debug_state current_debug_state = RUN;
  37 //debug_state current_debug_state = STEP_RUN;
  38
  39 //u32 breakpoint_value = 0;
  40
  41 frameskip_type current_frameskip_type = auto_frameskip;
  42 u32 global_cycles_per_instruction = 1;
  43 u32 random_skip = 0;
  44 u32 fps_debug = 0;
  45
  46 u32 frameskip_value = 2;
  47
  48 u64 last_frame_interval_timestamp;
  49
  50 u32 skip_next_frame = 0;
  51
  52 u32 frameskip_counter = 0;
  53
  54 u32 cpu_ticks = 0;
  55 u32 frame_ticks = 0;
  56
  57 u32 execute_cycles = 960;
  58 s32 video_count = 960;
  59 u32 ticks;
  60
  61 u32 arm_frame = 0;
  62 u32 thumb_frame = 0;
  63 u32 last_frame = 0;
  64
  65 u32 cycle_memory_access = 0;
  66 u32 cycle_pc_relative_access = 0;
  67 u32 cycle_sp_relative_access = 0;
  68 u32 cycle_block_memory_access = 0;
  69 u32 cycle_block_memory_sp_access = 0;
  70 u32 cycle_block_memory_words = 0;
  71 u32 cycle_dma16_words = 0;
  72 u32 cycle_dma32_words = 0;
  73 u32 flush_ram_count = 0;
  74 u32 gbc_update_count = 0;
  75 u32 oam_update_count = 0;
  76
  77 u32 synchronize_flag = 1;
  78
  79 u32 update_backup_flag = 1;
  80 #ifdef GP2X_BUILD
  81 u32 clock_speed = 200;
  82 #else
  83 u32 clock_speed = 333;
  84 #endif
  85 char main_path[512];
  86
  87 void trigger_ext_event();
  88
  89 #define check_count(count_var)                                                \
  90   if(count_var < execute_cycles)                                              \
  91     execute_cycles = count_var;                                               \
  92
  93 #define check_timer(timer_number)                                             \
  94   if(timer[timer_number].status == TIMER_PRESCALE)                            \
  95     check_count(timer[timer_number].count);                                   \
  96
  97 #define update_timer(timer_number)                                            \
  98   if(timer[timer_number].status != TIMER_INACTIVE)                            \
  99   {                                                                           \
 100     if(timer[timer_number].status != TIMER_CASCADE)                           \
 101     {                                                                         \
 102       timer[timer_number].count -= execute_cycles;                            \
 103       io_registers[REG_TM##timer_number##D] =                                 \
 104        -(timer[timer_number].count >> timer[timer_number].prescale);          \
 105     }                                                                         \
 106                                                                               \
 107     if(timer[timer_number].count <= 0)                                        \
 108     {                                                                         \
 109       if(timer[timer_number].irq == TIMER_TRIGGER_IRQ)                        \
 110         irq_raised |= IRQ_TIMER##timer_number;                                \
 111                                                                               \
 112       if((timer_number != 3) &&                                               \
 113        (timer[timer_number + 1].status == TIMER_CASCADE))                     \
 114       {                                                                       \
 115         timer[timer_number + 1].count--;                                      \
 116         io_registers[REG_TM0D + (timer_number + 1) * 2] =                     \
 117          -(timer[timer_number + 1].count);                                    \
 118       }                                                                       \
 119                                                                               \
 120       if(timer_number < 2)                                                    \
 121       {                                                                       \
 122         if(timer[timer_number].direct_sound_channels & 0x01)                  \
 123           sound_timer(timer[timer_number].frequency_step, 0);                 \
 124                                                                               \
 125         if(timer[timer_number].direct_sound_channels & 0x02)                  \
 126           sound_timer(timer[timer_number].frequency_step, 1);                 \
 127       }                                                                       \
 128                                                                               \
 129       timer[timer_number].count +=                                            \
 130        (timer[timer_number].reload << timer[timer_number].prescale);          \
 131     }                                                                         \
 132   }                                                                           \
 133
 134 static const char *file_ext[] = { ".gba", ".bin", ".zip", NULL };
 135
 136 #ifdef ARM_ARCH
 137 void ChangeWorkingDirectory(char *exe)
 138 {
 139 #ifndef _WIN32_WCE
 140   char *s = strrchr(exe, '/');
 141   if (s != NULL) {
 142     *s = '\0';
 143     chdir(exe);
 144     *s = '/';
 145   }
 146 #endif
 147 }
 148 #endif
 149
 150 void init_main()
 151 {
 152   u32 i;
 153
 154   skip_next_frame = 0;
 155
 156   for(i = 0; i < 4; i++)
 157   {
 158     dma[i].start_type = DMA_INACTIVE;
 159     dma[i].direct_sound_channel = DMA_NO_DIRECT_SOUND;
 160     timer[i].status = TIMER_INACTIVE;
 161     timer[i].reload = 0x10000;
 162     timer[i].stop_cpu_ticks = 0;
 163   }
 164
 165   timer[0].direct_sound_channels = TIMER_DS_CHANNEL_BOTH;
 166   timer[1].direct_sound_channels = TIMER_DS_CHANNEL_NONE;
 167
 168   cpu_ticks = 0;
 169   frame_ticks = 0;
 170
 171   execute_cycles = 960;
 172   video_count = 960;
 173
 174   flush_translation_cache_rom();
 175   flush_translation_cache_ram();
 176   flush_translation_cache_bios();
 177 }
 178
 179 int main(int argc, char *argv[])
 180 {
 181 #ifdef PSP_BUILD
 182   sceKernelRegisterSubIntrHandler(PSP_VBLANK_INT, 0,
 183    vblank_interrupt_handler, NULL);
 184   sceKernelEnableSubIntr(PSP_VBLANK_INT, 0);
 185 #endif
 186
 187   init_gamepak_buffer();
 188
 189   // Copy the directory path of the executable into main_path
 190
 191 #ifdef ARM_ARCH
 192   // ChangeWorkingDirectory will null out the filename out of the path
 193   ChangeWorkingDirectory(argv[0]);
 194 #endif
 195
 196   getcwd(main_path, 512);
 197
 198 #ifdef PSP_BUILD
 199   delay_us(2500000);
 200 #endif
 201
 202 #ifndef PC_BUILD
 203   gpsp_plat_init();
 204 #endif
 205   load_config_file();
 206
 207   gamepak_filename[0] = 0;
 208
 209   init_video();
 210
 211 #ifdef GP2X_BUILD
 212   char bios_filename[512];
 213   sprintf(bios_filename, "%s/%s", main_path, "gba_bios.bin");
 214   if(load_bios(bios_filename) == -1)
 215 #else
 216   if(load_bios("gba_bios.bin") == -1)
 217 #endif
 218   {
 219     gui_action_type gui_action = CURSOR_NONE;
 220
 221     debug_screen_start();
 222     debug_screen_printl("Sorry, but gpSP requires a Gameboy Advance BIOS   ");
 223     debug_screen_printl("image to run correctly. Make sure to get an       ");
 224     debug_screen_printl("authentic one, it'll be exactly 16384 bytes large ");
 225     debug_screen_printl("and should have the following md5sum value:       ");
 226     debug_screen_printl("                                                  ");
 227     debug_screen_printl("a860e8c0b6d573d191e4ec7db1b1e4f6                  ");
 228     debug_screen_printl("                                                  ");
 229     debug_screen_printl("When you do get it name it gba_bios.bin and put it");
 230 #ifdef PND_BUILD
 231     debug_screen_printl("in <CD card>/pandora/appdata/gpsp/ .              ");
 232 #else
 233     debug_screen_printl("in the same directory as gpSP.                    ");
 234 #endif
 235     debug_screen_printl("                                                  ");
 236     debug_screen_printl("Press any button to exit.                         ");
 237
 238     debug_screen_update();
 239
 240     while(gui_action == CURSOR_NONE)
 241     {
 242       gui_action = get_gui_input();
 243       delay_us(15000);
 244     }
 245
 246     debug_screen_end();
 247
 248     quit();
 249   }
 250
 251   if(bios_rom[0] != 0x18)
 252   {
 253     gui_action_type gui_action = CURSOR_NONE;
 254
 255     debug_screen_start();
 256     debug_screen_printl("You have an incorrect BIOS image.                 ");
 257     debug_screen_printl("While many games will work fine, some will not. It");
 258     debug_screen_printl("is strongly recommended that you obtain the       ");
 259     debug_screen_printl("correct BIOS file. Do NOT report any bugs if you  ");
 260     debug_screen_printl("are seeing this message.                          ");
 261     debug_screen_printl("                                                  ");
 262     debug_screen_printl("Press any button to resume, at your own risk.     ");
 263
 264     debug_screen_update();
 265
 266     while(gui_action == CURSOR_NONE)
 267     {
 268       gui_action = get_gui_input();
 269       delay_us(15000);
 270     }
 271
 272     debug_screen_end();
 273   }
 274
 275   init_main();
 276   init_sound();
 277
 278   init_input();
 279
 280   video_resolution_large();
 281
 282   if(argc > 1)
 283   {
 284     if(load_gamepak(argv[1]) == -1)
 285     {
 286 #ifndef PSP_BUILD
 287       printf("Failed to load gamepak %s, exiting.\n", argv[1]);
 288 #endif
 289       exit(-1);
 290     }
 291
 292     set_gba_resolution(screen_scale);
 293     video_resolution_small();
 294
 295     init_cpu();
 296     init_memory();
 297   }
 298   else
 299   {
 300     char load_filename[512];
 301     if(load_file(file_ext, load_filename) == -1)
 302     {
 303       menu(copy_screen());
 304     }
 305     else
 306     {
 307       if(load_gamepak(load_filename) == -1)
 308       {
 309 #ifndef PSP_BUILD
 310         printf("Failed to load gamepak %s, exiting.\n", load_filename);
 311 #endif
 312         exit(-1);
 313       }
 314
 315       set_clock_speed();
 316       set_gba_resolution(screen_scale);
 317       video_resolution_small();
 318
 319       init_cpu();
 320       init_memory();
 321     }
 322   }
 323
 324   last_frame = 0;
 325
 326   // We'll never actually return from here.
 327
 328 #ifdef PSP_BUILD
 329   execute_arm_translate(execute_cycles);
 330 #else
 331
 332 /*  u8 current_savestate_filename[512];
 333   get_savestate_filename_noshot(savestate_slot,
 334    current_savestate_filename);
 335   load_state(current_savestate_filename); */
 336
 337 //  debug_on();
 338
 339   if(argc > 2)
 340   {
 341     current_debug_state = COUNTDOWN_BREAKPOINT;
 342     breakpoint_value = strtol(argv[2], NULL, 16);
 343   }
 344
 345   trigger_ext_event();
 346
 347   execute_arm_translate(execute_cycles);
 348   execute_arm(execute_cycles);
 349 #endif
 350   return 0;
 351 }
 352
 353 void print_memory_stats(u32 *counter, u32 *region_stats, char *stats_str)
 354 {
 355   u32 other_region_counter = region_stats[0x1] + region_stats[0xE] +
 356    region_stats[0xF];
 357   u32 rom_region_counter = region_stats[0x8] + region_stats[0x9] +
 358    region_stats[0xA] + region_stats[0xB] + region_stats[0xC] +
 359    region_stats[0xD];
 360   u32 _counter = *counter;
 361
 362   printf("memory access stats: %s (out of %d)\n", stats_str, _counter);
 363   printf("bios: %f%%\tiwram: %f%%\tewram: %f%%\tvram: %f\n",
 364    region_stats[0x0] * 100.0 / _counter, region_stats[0x3] * 100.0 /
 365    _counter,
 366    region_stats[0x2] * 100.0 / _counter, region_stats[0x6] * 100.0 /
 367    _counter);
 368
 369   printf("oam: %f%%\tpalette: %f%%\trom: %f%%\tother: %f%%\n",
 370    region_stats[0x7] * 100.0 / _counter, region_stats[0x5] * 100.0 /
 371    _counter,
 372    rom_region_counter * 100.0 / _counter, other_region_counter * 100.0 /
 373    _counter);
 374
 375   *counter = 0;
 376   memset(region_stats, 0, sizeof(u32) * 16);
 377 }
 378
 379 u32 event_cycles = 0;
 380 const u32 event_cycles_trigger = 60 * 5;
 381 u32 no_alpha = 0;
 382
 383 void trigger_ext_event()
 384 {
 385   static u32 event_number = 0;
 386   static u64 benchmark_ticks[16];
 387   u64 new_ticks;
 388   char current_savestate_filename[512];
 389
 390   return;
 391
 392   if(event_number)
 393   {
 394     get_ticks_us(&new_ticks);
 395     benchmark_ticks[event_number - 1] =
 396      new_ticks - benchmark_ticks[event_number - 1];
 397   }
 398
 399   current_frameskip_type = no_frameskip;
 400   no_alpha = 0;
 401   synchronize_flag = 0;
 402
 403   get_savestate_filename_noshot(savestate_slot,
 404    current_savestate_filename);
 405   load_state(current_savestate_filename);
 406
 407   switch(event_number)
 408   {
 409     case 0:
 410       // Full benchmark, run normally
 411       break;
 412
 413     case 1:
 414       // No alpha blending
 415       no_alpha = 1;
 416       break;
 417
 418     case 2:
 419       // No video benchmark
 420       // Set frameskip really high + manual
 421       current_frameskip_type = manual_frameskip;
 422       frameskip_value = 1000000;
 423       break;
 424
 425     case 3:
 426       // No CPU benchmark
 427       // Put CPU in halt mode, put it in IRQ mode with interrupts off
 428       reg[CPU_HALT_STATE] = CPU_HALT;
 429       reg[REG_CPSR] = 0xD2;
 430       break;
 431
 432     case 4:
 433       // No CPU or video benchmark
 434       reg[CPU_HALT_STATE] = CPU_HALT;
 435       reg[REG_CPSR] = 0xD2;
 436       current_frameskip_type = manual_frameskip;
 437       frameskip_value = 1000000;
 438       break;
 439
 440     case 5:
 441     {
 442       // Done
 443       char *print_strings[] =
 444       {
 445         "Full test   ",
 446         "No blending ",
 447         "No video    ",
 448         "No CPU      ",
 449         "No CPU/video",
 450         "CPU speed   ",
 451         "Video speed ",
 452         "Alpha cost  "
 453       };
 454       u32 i;
 455
 456       benchmark_ticks[6] = benchmark_ticks[0] - benchmark_ticks[2];
 457       benchmark_ticks[5] = benchmark_ticks[0] - benchmark_ticks[4] -
 458        benchmark_ticks[6];
 459       benchmark_ticks[7] = benchmark_ticks[0] - benchmark_ticks[1];
 460
 461       printf("Benchmark results (%d frames): \n", event_cycles_trigger);
 462       for(i = 0; i < 8; i++)
 463       {
 464         printf("   %s: %d ms (%f ms per frame)\n",
 465          print_strings[i], (u32)benchmark_ticks[i] / 1000,
 466          (float)(benchmark_ticks[i] / (1000.0 * event_cycles_trigger)));
 467         if(i == 4)
 468           printf("\n");
 469       }
 470       quit();
 471     }
 472   }
 473
 474   event_cycles = 0;
 475
 476   get_ticks_us(benchmark_ticks + event_number);
 477   event_number++;
 478 }
 479
 480 static u32 fps = 60;
 481 static u32 frames_drawn = 60;
 482
 483 u32 update_gba()
 484 {
 485   irq_type irq_raised = IRQ_NONE;
 486
 487   do
 488   {
 489     cpu_ticks += execute_cycles;
 490
 491     reg[CHANGED_PC_STATUS] = 0;
 492
 493     if(gbc_sound_update)
 494     {
 495       gbc_update_count++;
 496       update_gbc_sound(cpu_ticks);
 497       gbc_sound_update = 0;
 498     }
 499
 500     update_timer(0);
 501     update_timer(1);
 502     update_timer(2);
 503     update_timer(3);
 504
 505     video_count -= execute_cycles;
 506
 507     if(video_count <= 0)
 508     {
 509       u32 vcount = io_registers[REG_VCOUNT];
 510       u32 dispstat = io_registers[REG_DISPSTAT];
 511
 512       if((dispstat & 0x02) == 0)
 513       {
 514         // Transition from hrefresh to hblank
 515         video_count += (272);
 516         dispstat |= 0x02;
 517
 518         if((dispstat & 0x01) == 0)
 519         {
 520           u32 i;
 521           if(oam_update)
 522             oam_update_count++;
 523
 524           if(no_alpha)
 525             io_registers[REG_BLDCNT] = 0;
 526           update_scanline();
 527
 528           // If in visible area also fire HDMA
 529           for(i = 0; i < 4; i++)
 530           {
 531             if(dma[i].start_type == DMA_START_HBLANK)
 532               dma_transfer(dma + i);
 533           }
 534         }
 535
 536         if(dispstat & 0x10)
 537           irq_raised |= IRQ_HBLANK;
 538       }
 539       else
 540       {
 541         // Transition from hblank to next line
 542         video_count += 960;
 543         dispstat &= ~0x02;
 544
 545         vcount++;
 546
 547         if(vcount == 160)
 548         {
 549           // Transition from vrefresh to vblank
 550           u32 i;
 551
 552           dispstat |= 0x01;
 553           if(dispstat & 0x8)
 554           {
 555             irq_raised |= IRQ_VBLANK;
 556           }
 557
 558           affine_reference_x[0] =
 559            (s32)(address32(io_registers, 0x28) << 4) >> 4;
 560           affine_reference_y[0] =
 561            (s32)(address32(io_registers, 0x2C) << 4) >> 4;
 562           affine_reference_x[1] =
 563            (s32)(address32(io_registers, 0x38) << 4) >> 4;
 564           affine_reference_y[1] =
 565            (s32)(address32(io_registers, 0x3C) << 4) >> 4;
 566
 567           for(i = 0; i < 4; i++)
 568           {
 569             if(dma[i].start_type == DMA_START_VBLANK)
 570               dma_transfer(dma + i);
 571           }
 572         }
 573         else
 574
 575         if(vcount == 228)
 576         {
 577           // Transition from vblank to next screen
 578           dispstat &= ~0x01;
 579           frame_ticks++;
 580
 581   #ifdef PC_BUILD
 582         printf("frame update (%x), %d instructions total, %d RAM flushes\n",
 583            reg[REG_PC], instruction_count - last_frame, flush_ram_count);
 584           last_frame = instruction_count;
 585
 586 /*          printf("%d gbc audio updates\n", gbc_update_count);
 587           printf("%d oam updates\n", oam_update_count); */
 588           gbc_update_count = 0;
 589           oam_update_count = 0;
 590           flush_ram_count = 0;
 591   #endif
 592
 593           if(update_input())
 594             continue;
 595
 596           update_gbc_sound(cpu_ticks);
 597
 598           if(fps_debug)
 599           {
 600             char print_buffer[32];
 601             sprintf(print_buffer, "%2d (%2d)", fps, frames_drawn);
 602             print_string(print_buffer, 0xFFFF, 0x000, 0, 0);
 603           }
 604           if(!synchronize_flag)
 605             print_string("-FF-", 0xFFFF, 0x000, 216, 0);
 606
 607           update_screen();
 608
 609           synchronize();
 610
 611           if(update_backup_flag)
 612             update_backup();
 613
 614           process_cheats();
 615
 616           event_cycles++;
 617           if(event_cycles == event_cycles_trigger)
 618           {
 619             trigger_ext_event();
 620             continue;
 621           }
 622
 623           vcount = 0;
 624         }
 625
 626         if(vcount == (dispstat >> 8))
 627         {
 628           // vcount trigger
 629           dispstat |= 0x04;
 630           if(dispstat & 0x20)
 631           {
 632             irq_raised |= IRQ_VCOUNT;
 633           }
 634         }
 635         else
 636         {
 637           dispstat &= ~0x04;
 638         }
 639
 640         io_registers[REG_VCOUNT] = vcount;
 641       }
 642       io_registers[REG_DISPSTAT] = dispstat;
 643     }
 644
 645     if(irq_raised)
 646       raise_interrupt(irq_raised);
 647
 648     execute_cycles = video_count;
 649
 650     check_timer(0);
 651     check_timer(1);
 652     check_timer(2);
 653     check_timer(3);
 654   } while(reg[CPU_HALT_STATE] != CPU_ACTIVE);
 655
 656   return execute_cycles;
 657 }
 658
 659 #ifdef PSP_BUILD
 660
 661 u32 real_frame_count = 0;
 662 u32 virtual_frame_count = 0;
 663 u32 num_skipped_frames = 0;
 664
 665 void vblank_interrupt_handler(u32 sub, u32 *parg)
 666 {
 667   real_frame_count++;
 668 }
 669
 670 void synchronize()
 671 {
 672   char char_buffer[64];
 673   u64 new_ticks, time_delta;
 674   s32 used_frameskip = frameskip_value;
 675
 676   if(!synchronize_flag)
 677   {
 678     used_frameskip = 4;
 679     virtual_frame_count = real_frame_count - 1;
 680   }
 681
 682   skip_next_frame = 0;
 683
 684   virtual_frame_count++;
 685
 686   if(real_frame_count >= virtual_frame_count)
 687   {
 688     if((real_frame_count > virtual_frame_count) &&
 689      (current_frameskip_type == auto_frameskip) &&
 690      (num_skipped_frames < frameskip_value))
 691     {
 692       skip_next_frame = 1;
 693       num_skipped_frames++;
 694     }
 695     else
 696     {
 697       virtual_frame_count = real_frame_count;
 698       num_skipped_frames = 0;
 699     }
 700
 701     // Here so that the home button return will eventually work.
 702     // If it's not running fullspeed anyway this won't really hurt
 703     // it much more.
 704
 705     delay_us(1);
 706   }
 707   else
 708   {
 709     if(synchronize_flag)
 710       sceDisplayWaitVblankStart();
 711   }
 712
 713   if(current_frameskip_type == manual_frameskip)
 714   {
 715     frameskip_counter = (frameskip_counter + 1) %
 716      (used_frameskip + 1);
 717     if(random_skip)
 718     {
 719       if(frameskip_counter != (rand() % (used_frameskip + 1)))
 720         skip_next_frame = 1;
 721     }
 722     else
 723     {
 724       if(frameskip_counter)
 725         skip_next_frame = 1;
 726     }
 727   }
 728
 729 /*  sprintf(char_buffer, "%08d %08d %d %d %d\n",
 730    real_frame_count, virtual_frame_count, num_skipped_frames,
 731    real_frame_count - virtual_frame_count, skip_next_frame);
 732   print_string(char_buffer, 0xFFFF, 0x0000, 0, 10); */
 733
 734 /*
 735     sprintf(char_buffer, "%02d %02d %06d %07d", frameskip, (u32)ms_needed,
 736      ram_translation_ptr - ram_translation_cache, rom_translation_ptr -
 737      rom_translation_cache);
 738     print_string(char_buffer, 0xFFFF, 0x0000, 0, 0);
 739 */
 740 }
 741
 742 #else
 743
 744 u32 real_frame_count = 0;
 745 u32 virtual_frame_count = 0;
 746 u32 num_skipped_frames = 0;
 747 u32 interval_skipped_frames;
 748 u32 frames;
 749
 750 const u32 frame_interval = 60;
 751
 752 void synchronize()
 753 {
 754   u64 new_ticks;
 755   u64 time_delta;
 756
 757   get_ticks_us(&new_ticks);
 758
 759   skip_next_frame = 0;
 760   virtual_frame_count++;
 761
 762   real_frame_count = (new_ticks * 3) / 50000;
 763
 764   if(real_frame_count >= virtual_frame_count)
 765   {
 766     if((real_frame_count > virtual_frame_count) &&
 767      (current_frameskip_type == auto_frameskip) &&
 768      (num_skipped_frames < frameskip_value))
 769     {
 770       skip_next_frame = 1;
 771       num_skipped_frames++;
 772     }
 773     else
 774     {
 775       virtual_frame_count = real_frame_count;
 776       num_skipped_frames = 0;
 777     }
 778   }
 779   else if (synchronize_flag)
 780   {
 781 #if defined(PND_BUILD)
 782     fb_wait_vsync();
 783 #elif !defined(GP2X_BUILD) // sleeping on GP2X is a bad idea
 784     delay_us((u64)virtual_frame_count * 50000 / 3 - new_ticks + 2);
 785 #endif
 786   }
 787
 788   frames++;
 789
 790   if(frames == frame_interval)
 791   {
 792     u32 new_fps;
 793     u32 new_frames_drawn;
 794
 795     time_delta = new_ticks - last_frame_interval_timestamp;
 796     new_fps = (u64)((u64)1000000 * (u64)frame_interval) / time_delta;
 797     new_frames_drawn =
 798      (frame_interval - interval_skipped_frames) * (60 / frame_interval);
 799
 800     // Left open for rolling averages
 801     fps = new_fps;
 802     frames_drawn = new_frames_drawn;
 803
 804     last_frame_interval_timestamp = new_ticks;
 805     interval_skipped_frames = 0;
 806     frames = 0;
 807   }
 808
 809   if(current_frameskip_type == manual_frameskip)
 810   {
 811     frameskip_counter = (frameskip_counter + 1) %
 812      (frameskip_value + 1);
 813     if(random_skip)
 814     {
 815       if(frameskip_counter != (rand() % (frameskip_value + 1)))
 816         skip_next_frame = 1;
 817     }
 818     else
 819     {
 820       if(frameskip_counter)
 821         skip_next_frame = 1;
 822     }
 823   }
 824
 825   interval_skipped_frames += skip_next_frame;
 826
 827 #if !defined(GP2X_BUILD) && !defined(PND_BUILD)
 828   char char_buffer[64];
 829   sprintf(char_buffer, "gpSP: %2d (%2d) fps", fps, frames_drawn);
 830   SDL_WM_SetCaption(char_buffer, "gpSP");
 831 #endif
 832 }
 833
 834 #endif
 835
 836 void quit()
 837 {
 838   if(!update_backup_flag)
 839     update_backup_force();
 840
 841   sound_exit();
 842
 843 #ifdef REGISTER_USAGE_ANALYZE
 844   print_register_usage();
 845 #endif
 846
 847 #ifdef PSP_BUILD
 848   sceKernelExitGame();
 849 #else
 850   SDL_Quit();
 851
 852 #ifndef PC_BUILD
 853   gpsp_plat_quit();
 854 #endif
 855
 856   exit(0);
 857 #endif
 858 }
 859
 860 void reset_gba()
 861 {
 862   init_main();
 863   init_memory();
 864   init_cpu();
 865   reset_sound();
 866 }
 867
 868 #ifdef PSP_BUILD
 869
 870 u32 file_length(char *filename, s32 dummy)
 871 {
 872   SceIoStat stats;
 873   sceIoGetstat(filename, &stats);
 874   return stats.st_size;
 875 }
 876
 877 void delay_us(u32 us_count)
 878 {
 879   sceKernelDelayThread(us_count);
 880 }
 881
 882 void get_ticks_us(u64 *tick_return)
 883 {
 884   u64 ticks;
 885   sceRtcGetCurrentTick(&ticks);
 886
 887   *tick_return = (ticks * 1000000) / sceRtcGetTickResolution();
 888 }
 889
 890 #else
 891
 892 u32 file_length(char *dummy, FILE *fp)
 893 {
 894   u32 length;
 895
 896   fseek(fp, 0, SEEK_END);
 897   length = ftell(fp);
 898   fseek(fp, 0, SEEK_SET);
 899
 900   return length;
 901 }
 902
 903 #ifdef PC_BUILD
 904
 905 void delay_us(u32 us_count)
 906 {
 907   SDL_Delay(us_count / 1000);
 908 }
 909
 910 void get_ticks_us(u64 *ticks_return)
 911 {
 912   *ticks_return = (u64)SDL_GetTicks() * 1000;
 913 }
 914
 915 #else
 916
 917 void delay_us(u32 us_count)
 918 {
 919   //usleep(us_count);
 920   SDL_Delay(us_count / 1000);
 921 }
 922
 923 void get_ticks_us(u64 *ticks_return)
 924 {
 925   struct timeval current_time;
 926   gettimeofday(&current_time, NULL);
 927
 928   *ticks_return =
 929    (u64)current_time.tv_sec * 1000000 + current_time.tv_usec;
 930 }
 931
 932 #endif
 933
 934 #endif
 935
 936 void change_ext(const char *src, char *buffer, const char *extension)
 937 {
 938   char *dot_position;
 939   strcpy(buffer, src);
 940   dot_position = strrchr(buffer, '.');
 941
 942   if(dot_position)
 943     strcpy(dot_position, extension);
 944 }
 945
 946 #define main_savestate_builder(type)                                          \
 947 void main_##type##_savestate(file_tag_type savestate_file)                    \
 948 {                                                                             \
 949   file_##type##_variable(savestate_file, cpu_ticks);                          \
 950   file_##type##_variable(savestate_file, execute_cycles);                     \
 951   file_##type##_variable(savestate_file, video_count);                        \
 952   file_##type##_array(savestate_file, timer);                                 \
 953 }                                                                             \
 954
 955 main_savestate_builder(read);
 956 main_savestate_builder(write_mem);
 957
 958
 959 void printout(void *str, u32 val)
 960 {
 961   printf(str, val);
 962 }
 963
 964 void set_clock_speed()
 965 {
 966   static u32 clock_speed_old = default_clock_speed;
 967   if (clock_speed != clock_speed_old)
 968   {
 969     printf("about to set CPU clock to %iMHz\n", clock_speed);
 970   #ifdef PSP_BUILD
 971     scePowerSetClockFrequency(clock_speed, clock_speed, clock_speed / 2);
 972   #elif defined(GP2X_BUILD)
 973     set_FCLK(clock_speed);
 974   #endif
 975     clock_speed_old = clock_speed;
 976   }
 977 }
 978