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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 727:f934967b77a3
prev689:9868667e3525
next736:a02d1475ccfd
author nkeynes
date Sun Jul 06 04:52:37 2008 +0000 (13 years ago)
permissions -rw-r--r--
last change Fix exit code from exit() being lost (from SH4 code)
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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 "mem.h"
    24 #include "dreamcast.h"
    25 #include "asic.h"
    26 #include "syscall.h"
    27 #include "gui.h"
    28 #include "aica/aica.h"
    29 #include "gdrom/ide.h"
    30 #include "maple/maple.h"
    31 #include "sh4/sh4.h"
    32 #include "sh4/sh4trans.h"
    34 /**
    35  * Current state of the DC virtual machine
    36  */
    37 typedef enum { STATE_UNINIT=0, STATE_RUNNING, 
    38 	       STATE_STOPPING, STATE_STOPPED } dreamcast_state_t;
    40 static volatile dreamcast_state_t dreamcast_state = STATE_UNINIT;
    41 static gboolean dreamcast_has_bios = FALSE;
    42 static gboolean dreamcast_exit_on_stop = FALSE;
    43 static gchar *dreamcast_program_name = NULL;
    44 static sh4addr_t dreamcast_entry_point = 0xA0000000;
    45 static uint32_t timeslice_length = DEFAULT_TIMESLICE_LENGTH;
    46 static uint64_t run_time_nanosecs = 0;
    48 #define MAX_MODULES 32
    49 static int num_modules = 0;
    50 dreamcast_module_t modules[MAX_MODULES];
    52 /**
    53  * The unknown module is used for logging files without an actual module
    54  * declaration
    55  */
    56 struct dreamcast_module unknown_module = { "****", NULL, NULL, NULL, NULL, 
    57 					   NULL, NULL, NULL };
    59 /**
    60  * This function is responsible for defining how all the pieces of the
    61  * dreamcast actually fit together. 
    62  *
    63  * Note currently the locations of the various MMIO pages are hard coded in
    64  * the MMIO definitions - they should probably be moved here.
    65  */
    66 void dreamcast_configure( )
    67 {
    68     dreamcast_register_module( &eventq_module );
    69     /* Register the memory framework */
    70     dreamcast_register_module( &mem_module );
    72     /* Setup standard memory map */
    73     mem_create_repeating_ram_region( 0x0C000000, 16 MB, MEM_REGION_MAIN, 0x01000000, 0x0F000000 );
    74     mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );
    75     mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );
    76     mem_create_ram_region( 0x05000000, 8 MB, MEM_REGION_VIDEO );
    77     dreamcast_has_bios = mem_load_rom( lxdream_get_config_value(CONFIG_BIOS_PATH),
    78 				       0x00000000, 0x00200000, 0x89f2b1a1,
    79 				       MEM_REGION_BIOS );
    80     mem_create_ram_region( 0x00200000, 0x00020000, MEM_REGION_FLASH );
    81     mem_load_block( lxdream_get_config_value(CONFIG_FLASH_PATH),
    82 		    0x00200000, 0x00020000 );
    84     /* Load in the rest of the core modules */
    85     dreamcast_register_module( &sh4_module );
    86     dreamcast_register_module( &asic_module );
    87     dreamcast_register_module( &pvr2_module );
    88     dreamcast_register_module( &aica_module );
    89     dreamcast_register_module( &maple_module );
    90     dreamcast_register_module( &ide_module );
    91 }
    93 void dreamcast_config_changed(void)
    94 {
    95     dreamcast_has_bios = mem_load_rom( lxdream_get_config_value(CONFIG_BIOS_PATH),
    96 				       0x00000000, 0x00200000, 0x89f2b1a1, 
    97 				       MEM_REGION_BIOS );
    98     mem_load_block( lxdream_get_config_value(CONFIG_FLASH_PATH),
    99 		    0x00200000, 0x00020000 );
   100 }
   102 void dreamcast_save_flash()
   103 {
   104     const char *file = lxdream_get_config_value(CONFIG_FLASH_PATH);
   105     mem_save_block( file, 0x00200000, 0x00020000 );
   106 }
   108 /**
   109  * Constructs a system configuration for the AICA in standalone mode,
   110  * ie sound chip only.
   111  */
   112 void dreamcast_configure_aica_only( )
   113 {
   114     dreamcast_register_module( &mem_module );
   115     mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );
   116     mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );
   117     dreamcast_register_module( &aica_module );
   118     aica_enable();
   119     dreamcast_state = STATE_STOPPED;
   120 }
   122 void dreamcast_register_module( dreamcast_module_t module ) 
   123 {
   124     modules[num_modules++] = module;
   125     if( module->init != NULL )
   126 	module->init();
   127 }
   129 void dreamcast_set_run_time( uint32_t secs, uint32_t nanosecs )
   130 {
   131     run_time_nanosecs = (((uint64_t)secs) * 1000000000) + nanosecs;
   132 }
   134 void dreamcast_set_exit_on_stop( gboolean flag )
   135 {
   136     dreamcast_exit_on_stop = flag;
   137 }
   139 void dreamcast_init( void )
   140 {
   141     dreamcast_configure();
   142     dreamcast_state = STATE_STOPPED;
   143 }
   145 void dreamcast_reset( void )
   146 {
   147     int i;
   148     if( sh4_xlat_is_running() ) {
   149 	sh4_translate_exit( XLAT_EXIT_SYSRESET );
   150     }
   151     for( i=0; i<num_modules; i++ ) {
   152 	if( modules[i]->reset != NULL )
   153 	    modules[i]->reset();
   154     }
   155 }
   157 void dreamcast_run( void )
   158 {
   159     int i;
   161     if( dreamcast_state != STATE_RUNNING ) {
   162         for( i=0; i<num_modules; i++ ) {
   163             if( modules[i]->start != NULL )
   164                 modules[i]->start();
   165         }
   166     }
   168     dreamcast_state = STATE_RUNNING;
   170     if( run_time_nanosecs != 0 ) {
   171         while( dreamcast_state == STATE_RUNNING ) {
   172             uint32_t time_to_run = timeslice_length;
   173             if( run_time_nanosecs < time_to_run ) {
   174                 time_to_run = (uint32_t)run_time_nanosecs;
   175             }
   177             for( i=0; i<num_modules; i++ ) {
   178                 if( modules[i]->run_time_slice != NULL )
   179                     time_to_run = modules[i]->run_time_slice( time_to_run );
   180             }
   182             if( run_time_nanosecs > time_to_run ) {
   183                 run_time_nanosecs -= time_to_run;
   184             } else {
   185                 run_time_nanosecs = 0; // Finished
   186                 break;
   187             }
   188         }
   189     } else {
   190         while( dreamcast_state == STATE_RUNNING ) {
   191             int time_to_run = timeslice_length;
   192             for( i=0; i<num_modules; i++ ) {
   193                 if( modules[i]->run_time_slice != NULL )
   194                     time_to_run = modules[i]->run_time_slice( time_to_run );
   195             }
   197         }
   198     }
   200     for( i=0; i<num_modules; i++ ) {
   201         if( modules[i]->stop != NULL )
   202             modules[i]->stop();
   203     }
   204     dreamcast_state = STATE_STOPPED;
   206     if( dreamcast_exit_on_stop ) {
   207         dreamcast_shutdown();
   208         exit(0);
   209     }
   210 }
   212 void dreamcast_stop( void )
   213 {
   214     if( sh4_xlat_is_running() ) {
   215 	sh4_translate_exit( XLAT_EXIT_HALT );
   216     }
   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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