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lxdream.org :: lxdream/src/dreamcast.c
lxdream 0.9.1
released Jun 29
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filename src/dreamcast.c
changeset 742:e730ba4938f6
prev740:dd11269ee48b
next766:336858fb0160
author nkeynes
date Fri Jul 18 11:08:02 2008 +0000 (13 years ago)
permissions -rw-r--r--
last change Avoid writing out the flash if we never allocated it (eg, AICA mode)
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     1 /**
     2  * $Id$
     3  * Central switchboard for the system. This pulls all the individual modules
     4  * together into some kind of coherent structure. This is also where you'd
     5  * add Naomi support, if I ever get a board to play with...
     6  *
     7  * Copyright (c) 2005 Nathan Keynes.
     8  *
     9  * This program is free software; you can redistribute it and/or modify
    10  * it under the terms of the GNU General Public License as published by
    11  * the Free Software Foundation; either version 2 of the License, or
    12  * (at your option) any later version.
    13  *
    14  * This program is distributed in the hope that it will be useful,
    15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    17  * GNU General Public License for more details.
    18  */
    20 #include <errno.h>
    21 #include <glib.h>
    22 #include "lxdream.h"
    23 #include "dream.h"
    24 #include "mem.h"
    25 #include "dreamcast.h"
    26 #include "asic.h"
    27 #include "syscall.h"
    28 #include "gui.h"
    29 #include "aica/aica.h"
    30 #include "gdrom/ide.h"
    31 #include "maple/maple.h"
    32 #include "sh4/sh4.h"
    33 #include "sh4/sh4core.h"
    35 /**
    36  * Current state of the DC virtual machine
    37  */
    38 typedef enum { STATE_UNINIT=0, STATE_RUNNING, 
    39                STATE_STOPPING, STATE_STOPPED } dreamcast_state_t;
    41 static volatile dreamcast_state_t dreamcast_state = STATE_UNINIT;
    42 static gboolean dreamcast_has_bios = FALSE;
    43 static gboolean dreamcast_has_flash = FALSE;
    44 static gboolean dreamcast_exit_on_stop = FALSE;
    45 static gchar *dreamcast_program_name = NULL;
    46 static sh4addr_t dreamcast_entry_point = 0xA0000000;
    47 static uint32_t timeslice_length = DEFAULT_TIMESLICE_LENGTH;
    48 static uint64_t run_time_nanosecs = 0;
    50 #define MAX_MODULES 32
    51 static int num_modules = 0;
    52 dreamcast_module_t modules[MAX_MODULES];
    54 /**
    55  * The unknown module is used for logging files without an actual module
    56  * declaration
    57  */
    58 struct dreamcast_module unknown_module = { "****", NULL, NULL, NULL, NULL, 
    59         NULL, NULL, NULL };
    61 /**
    62  * This function is responsible for defining how all the pieces of the
    63  * dreamcast actually fit together. 
    64  *
    65  * Note currently the locations of the various MMIO pages are hard coded in
    66  * the MMIO definitions - they should probably be moved here.
    67  */
    68 void dreamcast_configure( )
    69 {
    70     dreamcast_register_module( &eventq_module );
    71     /* Register the memory framework */
    72     dreamcast_register_module( &mem_module );
    74     /* Setup standard memory map */
    75     mem_create_repeating_ram_region( 0x0C000000, 16 MB, MEM_REGION_MAIN, 0x01000000, 0x0F000000 );
    76     mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );
    77     mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );
    78     mem_create_ram_region( 0x05000000, 8 MB, MEM_REGION_VIDEO );
    79     dreamcast_has_bios = mem_load_rom( lxdream_get_config_value(CONFIG_BIOS_PATH),
    80             0x00000000, 0x00200000, 0x89f2b1a1,
    81             MEM_REGION_BIOS );
    82     mem_create_ram_region( 0x00200000, 0x00020000, MEM_REGION_FLASH );
    83     mem_load_block( lxdream_get_config_value(CONFIG_FLASH_PATH),
    84                     0x00200000, 0x00020000 );
    85     dreamcast_has_flash = TRUE;
    87     /* Load in the rest of the core modules */
    88     dreamcast_register_module( &sh4_module );
    89     dreamcast_register_module( &asic_module );
    90     dreamcast_register_module( &pvr2_module );
    91     dreamcast_register_module( &aica_module );
    92     dreamcast_register_module( &maple_module );
    93     dreamcast_register_module( &ide_module );
    94 }
    96 void dreamcast_config_changed(void)
    97 {
    98     dreamcast_has_bios = mem_load_rom( lxdream_get_config_value(CONFIG_BIOS_PATH),
    99             0x00000000, 0x00200000, 0x89f2b1a1, 
   100             MEM_REGION_BIOS );
   101     mem_load_block( lxdream_get_config_value(CONFIG_FLASH_PATH),
   102                     0x00200000, 0x00020000 );
   103 }
   105 void dreamcast_save_flash()
   106 {
   107     if( dreamcast_has_flash ) {
   108         const char *file = lxdream_get_config_value(CONFIG_FLASH_PATH);
   109         mem_save_block( file, 0x00200000, 0x00020000 );
   110     }
   111 }
   113 /**
   114  * Constructs a system configuration for the AICA in standalone mode,
   115  * ie sound chip only.
   116  */
   117 void dreamcast_configure_aica_only( )
   118 {
   119     dreamcast_register_module( &mem_module );
   120     mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );
   121     mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );
   122     dreamcast_register_module( &aica_module );
   123     aica_enable();
   124     dreamcast_state = STATE_STOPPED;
   125 }
   127 void dreamcast_register_module( dreamcast_module_t module ) 
   128 {
   129     modules[num_modules++] = module;
   130     if( module->init != NULL )
   131         module->init();
   132 }
   134 void dreamcast_set_run_time( uint32_t secs, uint32_t nanosecs )
   135 {
   136     run_time_nanosecs = (((uint64_t)secs) * 1000000000) + nanosecs;
   137 }
   139 void dreamcast_set_exit_on_stop( gboolean flag )
   140 {
   141     dreamcast_exit_on_stop = flag;
   142 }
   144 void dreamcast_init( void )
   145 {
   146     dreamcast_configure();
   147     dreamcast_state = STATE_STOPPED;
   148 }
   150 void dreamcast_reset( void )
   151 {
   152     int i;
   153     for( i=0; i<num_modules; i++ ) {
   154         if( modules[i]->reset != NULL )
   155             modules[i]->reset();
   156     }
   157 }
   159 void dreamcast_run( void )
   160 {
   161     int i;
   163     if( dreamcast_state != STATE_RUNNING ) {
   164         for( i=0; i<num_modules; i++ ) {
   165             if( modules[i]->start != NULL )
   166                 modules[i]->start();
   167         }
   168     }
   170     dreamcast_state = STATE_RUNNING;
   172     if( run_time_nanosecs != 0 ) {
   173         while( dreamcast_state == STATE_RUNNING ) {
   174             uint32_t time_to_run = timeslice_length;
   175             if( run_time_nanosecs < time_to_run ) {
   176                 time_to_run = (uint32_t)run_time_nanosecs;
   177             }
   179             for( i=0; i<num_modules; i++ ) {
   180                 if( modules[i]->run_time_slice != NULL )
   181                     time_to_run = modules[i]->run_time_slice( time_to_run );
   182             }
   184             if( run_time_nanosecs > time_to_run ) {
   185                 run_time_nanosecs -= time_to_run;
   186             } else {
   187                 run_time_nanosecs = 0; // Finished
   188                 break;
   189             }
   190         }
   191     } else {
   192         while( dreamcast_state == STATE_RUNNING ) {
   193             int time_to_run = timeslice_length;
   194             for( i=0; i<num_modules; i++ ) {
   195                 if( modules[i]->run_time_slice != NULL )
   196                     time_to_run = modules[i]->run_time_slice( time_to_run );
   197             }
   199         }
   200     }
   202     for( i=0; i<num_modules; i++ ) {
   203         if( modules[i]->stop != NULL )
   204             modules[i]->stop();
   205     }
   206     dreamcast_state = STATE_STOPPED;
   208     if( dreamcast_exit_on_stop ) {
   209         dreamcast_shutdown();
   210         exit(0);
   211     }
   212 }
   214 void dreamcast_stop( void )
   215 {
   216     sh4_core_exit(CORE_EXIT_HALT); // returns only if not inside SH4 core
   217     if( dreamcast_state == STATE_RUNNING )
   218         dreamcast_state = STATE_STOPPING;
   219 }
   221 void dreamcast_shutdown()
   222 {
   223     // Don't do a dreamcast_stop - if we're calling this out of SH4 code,
   224     // it's a shutdown-and-quit event
   225     if( dreamcast_state == STATE_RUNNING )
   226         dreamcast_state = STATE_STOPPING;
   227     dreamcast_save_flash();
   228 #ifdef ENABLE_SH4STATS
   229     sh4_stats_print(stdout);
   230 #endif
   231 }
   233 void dreamcast_program_loaded( const gchar *name, sh4addr_t entry_point )
   234 {
   235     if( dreamcast_program_name != NULL ) {
   236         g_free(dreamcast_program_name);
   237     }
   238     dreamcast_program_name = g_strdup(name);
   239     dreamcast_entry_point = entry_point;
   240     sh4_set_pc(entry_point);
   241     bios_install();
   242     dcload_install();
   243     gui_update_state();
   244 }
   246 gboolean dreamcast_is_running( void )
   247 {
   248     return dreamcast_state == STATE_RUNNING;
   249 }
   251 gboolean dreamcast_can_run(void)
   252 {
   253     return dreamcast_state != STATE_UNINIT &&
   254     (dreamcast_has_bios || dreamcast_program_name != NULL);
   255 }
   257 /********************************* Save States *****************************/
   259 struct save_state_header {
   260     char magic[16];
   261     uint32_t version;
   262     uint32_t module_count;
   263 };
   265 struct chunk_header {
   266     char marker[4]; /* Always BLCK */
   267     char name[8]; /* Block (module) name */
   268     uint32_t block_length;
   269 };
   271 /**
   272  * Check the save state header to ensure that it is a valid, supported
   273  * file. 
   274  * @return the number of blocks following, or 0 if the file is invalid.
   275  */
   276 int dreamcast_read_save_state_header( FILE *f )
   277 {
   278     struct save_state_header header;
   279     if( fread( &header, sizeof(header), 1, f ) != 1 ) {
   280         return 0;
   281     }
   282     if( strncmp( header.magic, DREAMCAST_SAVE_MAGIC, 16 ) != 0 ) {
   283         ERROR( "Not a %s save state file", APP_NAME );
   284         return 0;
   285     }
   286     if( header.version != DREAMCAST_SAVE_VERSION ) {
   287         ERROR( "%s save state version not supported", APP_NAME );
   288         return 0;
   289     }
   290     if( header.module_count > MAX_MODULES ) {
   291         ERROR( "%s save state is corrupted (bad module count)", APP_NAME );
   292         return 0;
   293     }
   294     return header.module_count;
   295 }
   297 int dreamcast_write_chunk_header( const gchar *name, uint32_t length, FILE *f )
   298 {
   299     struct chunk_header head;
   301     memcpy( head.marker, "BLCK", 4 );
   302     memset( head.name, 0, 8 );
   303     memcpy( head.name, name, strlen(name) );
   304     head.block_length = length;
   305     return fwrite( &head, sizeof(head), 1, f );
   306 }
   309 frame_buffer_t dreamcast_load_preview( const gchar *filename )
   310 {
   311     int i;
   312     FILE *f = fopen( filename, "r" );
   313     if( f == NULL ) return NULL;
   315     int module_count = dreamcast_read_save_state_header(f);
   316     if( module_count <= 0 ) {
   317         fclose(f);
   318         return NULL;
   319     }
   320     for( i=0; i<module_count; i++ ) {
   321         struct chunk_header head;
   322         if( fread( &head, sizeof(head), 1, f ) != 1 ) {
   323             fclose(f);
   324             return NULL;
   325         }
   326         if( memcmp("BLCK", head.marker, 4) != 0 ) {
   327             fclose(f);
   328             return NULL;
   329         }
   331         if( strcmp("PVR2", head.name) == 0 ) {
   332             uint32_t buf_count;
   333             int has_front;
   334             fread( &buf_count, sizeof(buf_count), 1, f );
   335             fread( &has_front, sizeof(has_front), 1, f );
   336             if( buf_count != 0 && has_front ) {
   337                 frame_buffer_t result = read_png_from_stream(f);
   338                 fclose(f);
   339                 return result;
   340             }
   341             break;
   342         } else {
   343             fseek( f, head.block_length, SEEK_CUR );
   344         }
   345     }
   346     return NULL;
   347 }
   349 int dreamcast_load_state( const gchar *filename )
   350 {
   351     int i,j;
   352     int module_count;
   353     int have_read[MAX_MODULES];
   355     FILE *f = fopen( filename, "r" );
   356     if( f == NULL ) return errno;
   358     module_count = dreamcast_read_save_state_header(f);
   359     if( module_count <= 0 ) {
   360         fclose(f);
   361         return 1;
   362     }
   364     for( i=0; i<MAX_MODULES; i++ ) {
   365         have_read[i] = 0;
   366     }
   368     for( i=0; i<module_count; i++ ) {
   369         struct chunk_header chunk;
   370         fread( &chunk, sizeof(chunk), 1, f );
   371         if( strncmp(chunk.marker, "BLCK", 4) != 0 ) {
   372             ERROR( "%s save state is corrupted (missing block header %d)", APP_NAME, i );
   373             fclose(f);
   374             return 2;
   375         }
   377         /* Find the matching module by name */
   378         for( j=0; j<num_modules; j++ ) {
   379             if( strcmp(modules[j]->name,chunk.name) == 0 ) {
   380                 have_read[j] = 1;
   381                 if( modules[j]->load == NULL ) {
   382                     ERROR( "%s save state is corrupted (no loader for %s)", APP_NAME, modules[j]->name );
   383                     fclose(f);
   384                     return 2;
   385                 } else if( modules[j]->load(f) != 0 ) {
   386                     ERROR( "%s save state is corrupted (%s failed)", APP_NAME, modules[j]->name );
   387                     fclose(f);
   388                     return 2;
   389                 }
   390                 break;
   391             }
   392         }
   393         if( j == num_modules ) {
   394             fclose(f);
   395             ERROR( "%s save state contains unrecognized section", APP_NAME );
   396             return 2;
   397         }
   398     }
   400     /* Any modules that we didn't load - reset to the default state.
   401      * (ie it's not an error to skip a module if you don't actually
   402      * care about its state).
   403      */
   404     for( j=0; j<num_modules; j++ ) {
   405         if( have_read[j] == 0 && modules[j]->reset != NULL ) {
   406             modules[j]->reset();
   407         }
   408     }
   409     fclose(f);
   410     INFO( "Save state read from %s", filename );
   411     return 0;
   412 }
   414 int dreamcast_save_state( const gchar *filename )
   415 {
   416     int i;
   417     FILE *f;
   418     struct save_state_header header;
   420     f = fopen( filename, "w" );
   421     if( f == NULL )
   422         return errno;
   423     strcpy( header.magic, DREAMCAST_SAVE_MAGIC );
   424     header.version = DREAMCAST_SAVE_VERSION;
   425     header.module_count = 0;
   427     for( i=0; i<num_modules; i++ ) {
   428         if( modules[i]->save != NULL )
   429             header.module_count++;
   430     }
   431     fwrite( &header, sizeof(header), 1, f );
   432     for( i=0; i<num_modules; i++ ) {
   433         if( modules[i]->save != NULL ) {
   434             uint32_t blocklen, posn1, posn2;
   435             dreamcast_write_chunk_header( modules[i]->name, 0, f );
   436             posn1 = ftell(f);
   437             modules[i]->save(f);
   438             posn2 = ftell(f);
   439             blocklen = posn2 - posn1;
   440             fseek( f, posn1-4, SEEK_SET );
   441             fwrite( &blocklen, sizeof(blocklen), 1, f );
   442             fseek( f, posn2, SEEK_SET );
   443         }
   444     }
   445     fclose( f );
   446     INFO( "Save state written to %s", filename );
   447     return 0;
   448 }
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