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 u8 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 u8 *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   u32 i;
 182   u32 vcount = 0;
 183   u32 ticks;
 184   u32 dispstat;
 185   u8 load_filename[512];
 186   u8 bios_filename[512];
 187
 188 #ifdef PSP_BUILD
 189   sceKernelRegisterSubIntrHandler(PSP_VBLANK_INT, 0,
 190    vblank_interrupt_handler, NULL);
 191   sceKernelEnableSubIntr(PSP_VBLANK_INT, 0);
 192 #endif
 193
 194   extern char *cpu_mode_names[];
 195
 196   init_gamepak_buffer();
 197
 198   // Copy the directory path of the executable into main_path
 199
 200 #ifdef ARM_ARCH
 201   // ChangeWorkingDirectory will null out the filename out of the path
 202   ChangeWorkingDirectory(argv[0]);
 203 #endif
 204
 205   getcwd(main_path, 512);
 206   load_config_file();
 207
 208   gamepak_filename[0] = 0;
 209
 210 #ifdef PSP_BUILD
 211   delay_us(2500000);
 212 #endif
 213
 214 #ifndef PC_BUILD
 215   gpsp_plat_init();
 216 #endif
 217
 218   init_video();
 219
 220 #ifdef GP2X_BUILD
 221   sprintf(bios_filename, "%s/%s", main_path, "gba_bios.bin");
 222   if(load_bios(bios_filename) == -1)
 223 #else
 224   if(load_bios("gba_bios.bin") == -1)
 225 #endif
 226   {
 227     gui_action_type gui_action = CURSOR_NONE;
 228
 229     debug_screen_start();
 230     debug_screen_printl("Sorry, but gpSP requires a Gameboy Advance BIOS   ");
 231     debug_screen_printl("image to run correctly. Make sure to get an       ");
 232     debug_screen_printl("authentic one, it'll be exactly 16384 bytes large ");
 233     debug_screen_printl("and should have the following md5sum value:       ");
 234     debug_screen_printl("                                                  ");
 235     debug_screen_printl("a860e8c0b6d573d191e4ec7db1b1e4f6                  ");
 236     debug_screen_printl("                                                  ");
 237     debug_screen_printl("When you do get it name it gba_bios.bin and put it");
 238     debug_screen_printl("in the same directory as gpSP.                    ");
 239     debug_screen_printl("                                                  ");
 240     debug_screen_printl("Press any button to exit.                         ");
 241
 242     debug_screen_update();
 243
 244     while(gui_action == CURSOR_NONE)
 245     {
 246       gui_action = get_gui_input();
 247       delay_us(15000);
 248     }
 249
 250     debug_screen_end();
 251
 252     quit();
 253   }
 254
 255   if(bios_rom[0] != 0x18)
 256   {
 257     gui_action_type gui_action = CURSOR_NONE;
 258
 259     debug_screen_start();
 260     debug_screen_printl("You have an incorrect BIOS image.                 ");
 261     debug_screen_printl("While many games will work fine, some will not. It");
 262     debug_screen_printl("is strongly recommended that you obtain the       ");
 263     debug_screen_printl("correct BIOS file. Do NOT report any bugs if you  ");
 264     debug_screen_printl("are seeing this message.                          ");
 265     debug_screen_printl("                                                  ");
 266     debug_screen_printl("Press any button to resume, at your own risk.     ");
 267
 268     debug_screen_update();
 269
 270     while(gui_action == CURSOR_NONE)
 271     {
 272       gui_action = get_gui_input();
 273       delay_us(15000);
 274     }
 275
 276     debug_screen_end();
 277   }
 278
 279   init_main();
 280   init_sound();
 281
 282   init_input();
 283
 284   video_resolution_large();
 285
 286   if(argc > 1)
 287   {
 288     if(load_gamepak(argv[1]) == -1)
 289     {
 290 #ifndef PSP_BUILD
 291       printf("Failed to load gamepak %s, exiting.\n", load_filename);
 292 #endif
 293       exit(-1);
 294     }
 295
 296     set_gba_resolution(screen_scale);
 297     video_resolution_small();
 298
 299     init_cpu();
 300     init_memory();
 301   }
 302   else
 303   {
 304     if(load_file(file_ext, load_filename) == -1)
 305     {
 306       menu(copy_screen());
 307     }
 308     else
 309     {
 310       if(load_gamepak(load_filename) == -1)
 311       {
 312 #ifndef PSP_BUILD
 313         printf("Failed to load gamepak %s, exiting.\n", load_filename);
 314 #endif
 315         exit(-1);
 316       }
 317
 318       set_clock_speed();
 319       set_gba_resolution(screen_scale);
 320       video_resolution_small();
 321
 322       init_cpu();
 323       init_memory();
 324     }
 325   }
 326
 327   last_frame = 0;
 328
 329   // We'll never actually return from here.
 330
 331 #ifdef PSP_BUILD
 332   execute_arm_translate(execute_cycles);
 333 #else
 334
 335 /*  u8 current_savestate_filename[512];
 336   get_savestate_filename_noshot(savestate_slot,
 337    current_savestate_filename);
 338   load_state(current_savestate_filename); */
 339
 340 //  debug_on();
 341
 342   if(argc > 2)
 343   {
 344     current_debug_state = COUNTDOWN_BREAKPOINT;
 345     breakpoint_value = strtol(argv[2], NULL, 16);
 346   }
 347
 348   trigger_ext_event();
 349
 350   execute_arm_translate(execute_cycles);
 351   execute_arm(execute_cycles);
 352 #endif
 353   return 0;
 354 }
 355
 356 void print_memory_stats(u32 *counter, u32 *region_stats, char *stats_str)
 357 {
 358   u32 other_region_counter = region_stats[0x1] + region_stats[0xE] +
 359    region_stats[0xF];
 360   u32 rom_region_counter = region_stats[0x8] + region_stats[0x9] +
 361    region_stats[0xA] + region_stats[0xB] + region_stats[0xC] +
 362    region_stats[0xD];
 363   u32 _counter = *counter;
 364
 365   printf("memory access stats: %s (out of %d)\n", stats_str, _counter);
 366   printf("bios: %f%%\tiwram: %f%%\tewram: %f%%\tvram: %f\n",
 367    region_stats[0x0] * 100.0 / _counter, region_stats[0x3] * 100.0 /
 368    _counter,
 369    region_stats[0x2] * 100.0 / _counter, region_stats[0x6] * 100.0 /
 370    _counter);
 371
 372   printf("oam: %f%%\tpalette: %f%%\trom: %f%%\tother: %f%%\n",
 373    region_stats[0x7] * 100.0 / _counter, region_stats[0x5] * 100.0 /
 374    _counter,
 375    rom_region_counter * 100.0 / _counter, other_region_counter * 100.0 /
 376    _counter);
 377
 378   *counter = 0;
 379   memset(region_stats, 0, sizeof(u32) * 16);
 380 }
 381
 382 u32 event_cycles = 0;
 383 const u32 event_cycles_trigger = 60 * 5;
 384 u32 no_alpha = 0;
 385
 386 void trigger_ext_event()
 387 {
 388   static u32 event_number = 0;
 389   static u64 benchmark_ticks[16];
 390   u64 new_ticks;
 391   u8 current_savestate_filename[512];
 392
 393   return;
 394
 395   if(event_number)
 396   {
 397     get_ticks_us(&new_ticks);
 398     benchmark_ticks[event_number - 1] =
 399      new_ticks - benchmark_ticks[event_number - 1];
 400   }
 401
 402   current_frameskip_type = no_frameskip;
 403   no_alpha = 0;
 404   synchronize_flag = 0;
 405
 406   get_savestate_filename_noshot(savestate_slot,
 407    current_savestate_filename);
 408   load_state(current_savestate_filename);
 409
 410   switch(event_number)
 411   {
 412     case 0:
 413       // Full benchmark, run normally
 414       break;
 415
 416     case 1:
 417       // No alpha blending
 418       no_alpha = 1;
 419       break;
 420
 421     case 2:
 422       // No video benchmark
 423       // Set frameskip really high + manual
 424       current_frameskip_type = manual_frameskip;
 425       frameskip_value = 1000000;
 426       break;
 427
 428     case 3:
 429       // No CPU benchmark
 430       // Put CPU in halt mode, put it in IRQ mode with interrupts off
 431       reg[CPU_HALT_STATE] = CPU_HALT;
 432       reg[REG_CPSR] = 0xD2;
 433       break;
 434
 435     case 4:
 436       // No CPU or video benchmark
 437       reg[CPU_HALT_STATE] = CPU_HALT;
 438       reg[REG_CPSR] = 0xD2;
 439       current_frameskip_type = manual_frameskip;
 440       frameskip_value = 1000000;
 441       break;
 442
 443     case 5:
 444     {
 445       // Done
 446       char *print_strings[] =
 447       {
 448         "Full test   ",
 449         "No blending ",
 450         "No video    ",
 451         "No CPU      ",
 452         "No CPU/video",
 453         "CPU speed   ",
 454         "Video speed ",
 455         "Alpha cost  "
 456       };
 457       u32 i;
 458
 459       benchmark_ticks[6] = benchmark_ticks[0] - benchmark_ticks[2];
 460       benchmark_ticks[5] = benchmark_ticks[0] - benchmark_ticks[4] -
 461        benchmark_ticks[6];
 462       benchmark_ticks[7] = benchmark_ticks[0] - benchmark_ticks[1];
 463
 464       printf("Benchmark results (%d frames): \n", event_cycles_trigger);
 465       for(i = 0; i < 8; i++)
 466       {
 467         printf("   %s: %d ms (%f ms per frame)\n",
 468          print_strings[i], (u32)benchmark_ticks[i] / 1000,
 469          (float)(benchmark_ticks[i] / (1000.0 * event_cycles_trigger)));
 470         if(i == 4)
 471           printf("\n");
 472       }
 473       quit();
 474     }
 475   }
 476
 477   event_cycles = 0;
 478
 479   get_ticks_us(benchmark_ticks + event_number);
 480   event_number++;
 481 }
 482
 483 static u32 fps = 60;
 484 static u32 frames_drawn = 60;
 485
 486 u32 update_gba()
 487 {
 488   irq_type irq_raised = IRQ_NONE;
 489
 490   do
 491   {
 492     cpu_ticks += execute_cycles;
 493
 494     reg[CHANGED_PC_STATUS] = 0;
 495
 496     if(gbc_sound_update)
 497     {
 498       gbc_update_count++;
 499       update_gbc_sound(cpu_ticks);
 500       gbc_sound_update = 0;
 501     }
 502
 503     update_timer(0);
 504     update_timer(1);
 505     update_timer(2);
 506     update_timer(3);
 507
 508     video_count -= execute_cycles;
 509
 510     if(video_count <= 0)
 511     {
 512       u32 vcount = io_registers[REG_VCOUNT];
 513       u32 dispstat = io_registers[REG_DISPSTAT];
 514
 515       if((dispstat & 0x02) == 0)
 516       {
 517         // Transition from hrefresh to hblank
 518         video_count += (272);
 519         dispstat |= 0x02;
 520
 521         if((dispstat & 0x01) == 0)
 522         {
 523           u32 i;
 524           if(oam_update)
 525             oam_update_count++;
 526
 527           if(no_alpha)
 528             io_registers[REG_BLDCNT] = 0;
 529           update_scanline();
 530
 531           // If in visible area also fire HDMA
 532           for(i = 0; i < 4; i++)
 533           {
 534             if(dma[i].start_type == DMA_START_HBLANK)
 535               dma_transfer(dma + i);
 536           }
 537         }
 538
 539         if(dispstat & 0x10)
 540           irq_raised |= IRQ_HBLANK;
 541       }
 542       else
 543       {
 544         // Transition from hblank to next line
 545         video_count += 960;
 546         dispstat &= ~0x02;
 547
 548         vcount++;
 549
 550         if(vcount == 160)
 551         {
 552           // Transition from vrefresh to vblank
 553           u32 i;
 554
 555           dispstat |= 0x01;
 556           if(dispstat & 0x8)
 557           {
 558             irq_raised |= IRQ_VBLANK;
 559           }
 560
 561           affine_reference_x[0] =
 562            (s32)(address32(io_registers, 0x28) << 4) >> 4;
 563           affine_reference_y[0] =
 564            (s32)(address32(io_registers, 0x2C) << 4) >> 4;
 565           affine_reference_x[1] =
 566            (s32)(address32(io_registers, 0x38) << 4) >> 4;
 567           affine_reference_y[1] =
 568            (s32)(address32(io_registers, 0x3C) << 4) >> 4;
 569
 570           for(i = 0; i < 4; i++)
 571           {
 572             if(dma[i].start_type == DMA_START_VBLANK)
 573               dma_transfer(dma + i);
 574           }
 575         }
 576         else
 577
 578         if(vcount == 228)
 579         {
 580           // Transition from vblank to next screen
 581           dispstat &= ~0x01;
 582           frame_ticks++;
 583
 584   #ifdef PC_BUILD
 585         printf("frame update (%x), %d instructions total, %d RAM flushes\n",
 586            reg[REG_PC], instruction_count - last_frame, flush_ram_count);
 587           last_frame = instruction_count;
 588
 589 /*          printf("%d gbc audio updates\n", gbc_update_count);
 590           printf("%d oam updates\n", oam_update_count); */
 591           gbc_update_count = 0;
 592           oam_update_count = 0;
 593           flush_ram_count = 0;
 594   #endif
 595
 596           if(update_input())
 597             continue;
 598
 599           update_gbc_sound(cpu_ticks);
 600
 601           if(fps_debug)
 602           {
 603             char print_buffer[32];
 604             sprintf(print_buffer, "%2d (%2d)", fps, frames_drawn);
 605             print_string(print_buffer, 0xFFFF, 0x000, 0, 0);
 606           }
 607           if(!synchronize_flag)
 608             print_string("-FF-", 0xFFFF, 0x000, 216, 0);
 609
 610           update_screen();
 611
 612           synchronize();
 613
 614           if(update_backup_flag)
 615             update_backup();
 616
 617           process_cheats();
 618
 619           event_cycles++;
 620           if(event_cycles == event_cycles_trigger)
 621           {
 622             trigger_ext_event();
 623             continue;
 624           }
 625
 626           vcount = 0;
 627         }
 628
 629         if(vcount == (dispstat >> 8))
 630         {
 631           // vcount trigger
 632           dispstat |= 0x04;
 633           if(dispstat & 0x20)
 634           {
 635             irq_raised |= IRQ_VCOUNT;
 636           }
 637         }
 638         else
 639         {
 640           dispstat &= ~0x04;
 641         }
 642
 643         io_registers[REG_VCOUNT] = vcount;
 644       }
 645       io_registers[REG_DISPSTAT] = dispstat;
 646     }
 647
 648     if(irq_raised)
 649       raise_interrupt(irq_raised);
 650
 651     execute_cycles = video_count;
 652
 653     check_timer(0);
 654     check_timer(1);
 655     check_timer(2);
 656     check_timer(3);
 657   } while(reg[CPU_HALT_STATE] != CPU_ACTIVE);
 658
 659   return execute_cycles;
 660 }
 661
 662 #ifdef PSP_BUILD
 663
 664 u32 real_frame_count = 0;
 665 u32 virtual_frame_count = 0;
 666 u32 num_skipped_frames = 0;
 667
 668 void vblank_interrupt_handler(u32 sub, u32 *parg)
 669 {
 670   real_frame_count++;
 671 }
 672
 673 void synchronize()
 674 {
 675   char char_buffer[64];
 676   u64 new_ticks, time_delta;
 677   s32 used_frameskip = frameskip_value;
 678
 679   if(!synchronize_flag)
 680   {
 681     used_frameskip = 4;
 682     virtual_frame_count = real_frame_count - 1;
 683   }
 684
 685   skip_next_frame = 0;
 686
 687   virtual_frame_count++;
 688
 689   if(real_frame_count >= virtual_frame_count)
 690   {
 691     if((real_frame_count > virtual_frame_count) &&
 692      (current_frameskip_type == auto_frameskip) &&
 693      (num_skipped_frames < frameskip_value))
 694     {
 695       skip_next_frame = 1;
 696       num_skipped_frames++;
 697     }
 698     else
 699     {
 700       virtual_frame_count = real_frame_count;
 701       num_skipped_frames = 0;
 702     }
 703
 704     // Here so that the home button return will eventually work.
 705     // If it's not running fullspeed anyway this won't really hurt
 706     // it much more.
 707
 708     delay_us(1);
 709   }
 710   else
 711   {
 712     if(synchronize_flag)
 713       sceDisplayWaitVblankStart();
 714   }
 715
 716   if(current_frameskip_type == manual_frameskip)
 717   {
 718     frameskip_counter = (frameskip_counter + 1) %
 719      (used_frameskip + 1);
 720     if(random_skip)
 721     {
 722       if(frameskip_counter != (rand() % (used_frameskip + 1)))
 723         skip_next_frame = 1;
 724     }
 725     else
 726     {
 727       if(frameskip_counter)
 728         skip_next_frame = 1;
 729     }
 730   }
 731
 732 /*  sprintf(char_buffer, "%08d %08d %d %d %d\n",
 733    real_frame_count, virtual_frame_count, num_skipped_frames,
 734    real_frame_count - virtual_frame_count, skip_next_frame);
 735   print_string(char_buffer, 0xFFFF, 0x0000, 0, 10); */
 736
 737 /*
 738     sprintf(char_buffer, "%02d %02d %06d %07d", frameskip, (u32)ms_needed,
 739      ram_translation_ptr - ram_translation_cache, rom_translation_ptr -
 740      rom_translation_cache);
 741     print_string(char_buffer, 0xFFFF, 0x0000, 0, 0);
 742 */
 743 }
 744
 745 #else
 746
 747 u32 real_frame_count = 0;
 748 u32 virtual_frame_count = 0;
 749 u32 num_skipped_frames = 0;
 750 u32 interval_skipped_frames;
 751 u32 frames;
 752
 753 const u32 frame_interval = 60;
 754
 755 void synchronize()
 756 {
 757   u64 new_ticks;
 758   u64 time_delta;
 759
 760   get_ticks_us(&new_ticks);
 761
 762   skip_next_frame = 0;
 763   virtual_frame_count++;
 764
 765   real_frame_count = (new_ticks * 3) / 50000;
 766
 767   if(real_frame_count >= virtual_frame_count)
 768   {
 769     if((real_frame_count > virtual_frame_count) &&
 770      (current_frameskip_type == auto_frameskip) &&
 771      (num_skipped_frames < frameskip_value))
 772     {
 773       skip_next_frame = 1;
 774       num_skipped_frames++;
 775     }
 776     else
 777     {
 778       virtual_frame_count = real_frame_count;
 779       num_skipped_frames = 0;
 780     }
 781   }
 782   else if (synchronize_flag)
 783   {
 784 #if defined(PND_BUILD)
 785     fb_wait_vsync();
 786 #elif !defined(GP2X_BUILD) // sleeping on GP2X is a bad idea
 787     delay_us((u64)virtual_frame_count * 50000 / 3 - new_ticks + 2);
 788 #endif
 789   }
 790
 791   frames++;
 792
 793   if(frames == frame_interval)
 794   {
 795     u32 new_fps;
 796     u32 new_frames_drawn;
 797
 798     time_delta = new_ticks - last_frame_interval_timestamp;
 799     new_fps = (u64)((u64)1000000 * (u64)frame_interval) / time_delta;
 800     new_frames_drawn =
 801      (frame_interval - interval_skipped_frames) * (60 / frame_interval);
 802
 803     // Left open for rolling averages
 804     fps = new_fps;
 805     frames_drawn = new_frames_drawn;
 806
 807     last_frame_interval_timestamp = new_ticks;
 808     interval_skipped_frames = 0;
 809     frames = 0;
 810   }
 811
 812   if(current_frameskip_type == manual_frameskip)
 813   {
 814     frameskip_counter = (frameskip_counter + 1) %
 815      (frameskip_value + 1);
 816     if(random_skip)
 817     {
 818       if(frameskip_counter != (rand() % (frameskip_value + 1)))
 819         skip_next_frame = 1;
 820     }
 821     else
 822     {
 823       if(frameskip_counter)
 824         skip_next_frame = 1;
 825     }
 826   }
 827
 828   interval_skipped_frames += skip_next_frame;
 829
 830 #if !defined(GP2X_BUILD) && !defined(PND_BUILD)
 831   char char_buffer[64];
 832   sprintf(char_buffer, "gpSP: %2d (%2d) fps", fps, frames_drawn);
 833   SDL_WM_SetCaption(char_buffer, "gpSP");
 834 #endif
 835 }
 836
 837 #endif
 838
 839 void quit()
 840 {
 841   if(!update_backup_flag)
 842     update_backup_force();
 843
 844   sound_exit();
 845
 846 #ifdef REGISTER_USAGE_ANALYZE
 847   print_register_usage();
 848 #endif
 849
 850 #ifdef PSP_BUILD
 851   sceKernelExitGame();
 852 #else
 853   SDL_Quit();
 854
 855 #ifndef PC_BUILD
 856   gpsp_plat_quit();
 857 #endif
 858
 859   exit(0);
 860 #endif
 861 }
 862
 863 void reset_gba()
 864 {
 865   init_main();
 866   init_memory();
 867   init_cpu();
 868   reset_sound();
 869 }
 870
 871 #ifdef PSP_BUILD
 872
 873 u32 file_length(u8 *filename, s32 dummy)
 874 {
 875   SceIoStat stats;
 876   sceIoGetstat(filename, &stats);
 877   return stats.st_size;
 878 }
 879
 880 void delay_us(u32 us_count)
 881 {
 882   sceKernelDelayThread(us_count);
 883 }
 884
 885 void get_ticks_us(u64 *tick_return)
 886 {
 887   u64 ticks;
 888   sceRtcGetCurrentTick(&ticks);
 889
 890   *tick_return = (ticks * 1000000) / sceRtcGetTickResolution();
 891 }
 892
 893 #else
 894
 895 u32 file_length(u8 *dummy, FILE *fp)
 896 {
 897   u32 length;
 898
 899   fseek(fp, 0, SEEK_END);
 900   length = ftell(fp);
 901   fseek(fp, 0, SEEK_SET);
 902
 903   return length;
 904 }
 905
 906 #ifdef PC_BUILD
 907
 908 void delay_us(u32 us_count)
 909 {
 910   SDL_Delay(us_count / 1000);
 911 }
 912
 913 void get_ticks_us(u64 *ticks_return)
 914 {
 915   *ticks_return = (u64)SDL_GetTicks() * 1000;
 916 }
 917
 918 #else
 919
 920 void delay_us(u32 us_count)
 921 {
 922   //usleep(us_count);
 923   SDL_Delay(us_count / 1000);
 924 }
 925
 926 void get_ticks_us(u64 *ticks_return)
 927 {
 928   struct timeval current_time;
 929   gettimeofday(&current_time, NULL);
 930
 931   *ticks_return =
 932    (u64)current_time.tv_sec * 1000000 + current_time.tv_usec;
 933 }
 934
 935 #endif
 936
 937 #endif
 938
 939 void change_ext(u8 *src, u8 *buffer, u8 *extension)
 940 {
 941   u8 *dot_position;
 942   strcpy(buffer, src);
 943   dot_position = strrchr(buffer, '.');
 944
 945   if(dot_position)
 946     strcpy(dot_position, extension);
 947 }
 948
 949 #define main_savestate_builder(type)                                          \
 950 void main_##type##_savestate(file_tag_type savestate_file)                    \
 951 {                                                                             \
 952   file_##type##_variable(savestate_file, cpu_ticks);                          \
 953   file_##type##_variable(savestate_file, execute_cycles);                     \
 954   file_##type##_variable(savestate_file, video_count);                        \
 955   file_##type##_array(savestate_file, timer);                                 \
 956 }                                                                             \
 957
 958 main_savestate_builder(read);
 959 main_savestate_builder(write_mem);
 960
 961
 962 void printout(void *str, u32 val)
 963 {
 964   printf(str, val);
 965 }
 966
 967 void set_clock_speed()
 968 {
 969   static u32 clock_speed_old = default_clock_speed;
 970   if (clock_speed != clock_speed_old)
 971   {
 972     printf("about to set CPU clock to %iMHz\n", clock_speed);
 973   #ifdef PSP_BUILD
 974     scePowerSetClockFrequency(clock_speed, clock_speed, clock_speed / 2);
 975   #elif defined(GP2X_BUILD)
 976     set_FCLK(clock_speed);
 977   #endif
 978     clock_speed_old = clock_speed;
 979   }
 980 }
 981